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1

Design of an Alternative Coolant Inlet Flow Configuaration for the Modular Helium Reactor  

SciTech Connect

The coolant outlet temperature for the Modular Helium Reactor (MHR) was increased to improve the overall efficiency of nuclear hydrogen production using either thermochemical or high temperature electrolysis (HTE) processes. The inlet temperature was also increased to keep about the same _T across the reactor core. Thermal hydraulic analyses of the current MHR design were performed with these updated temperatures to determine the impact of these highter temperatures on pressure drops, coolant flow rates and temperature profiles within the vessel and core regions. Due to these increased operating temperatures, the overall efficiency of hydrogen production processes increases but the steady state reactor vessel temperature is found to be well above the ASME code limits for current vessel materials. Using the RELAP5-3D/ATHENA computer code, an alternative configuration for the MHR coolant inlet flow path was evaluated in an attempt to reduce the reactor vessel temperatures. The coolant inlet flow was shifted from channel boxes located in the annular region between the reactor core barrel and the inner wall of the reactor vessel to a flow path through the outer permanent reflector. Considering the available thickness of graphite in the permanent outer reflector, the total flow area, the number of coolant holes and the coolant-hole diameter were varied to optimize the pressure drop, the coolant inlet velocity and the percentage of graphite removed from the core. The resulting thermal hydraulic analyses of the optimized design showed that peak vessel and fuel temperatures were within acceptable limits for both steady-state and transient operating conditions.

SM Mohsin Reza; E. A. Harvego; Matt Richards; Arkal Shenoy; Kenneth Lee Peddicord

2006-06-01

2

Turbine vane coolant flow variations and calculated effects on metal temperatures  

NASA Technical Reports Server (NTRS)

Seventy-two air-cooled turbine vanes were tested to determine coolant flow variations among the vanes. Calculations were made to estimate the effect of measured coolant flow variations on local vane metal temperatures. The calculations were based on the following assumed operating conditions: turbine inlet temperature, 1700 K (2600 F); turbine inlet pressure, 31 N/sq cm (45 psia); coolant inlet temperature, 811 K (1000 F); and total coolant to gas flow ratio, 0.065. Variations of total coolant flow were not large (about 10 percent from the arithmetic mean) for all 72 vanes, but variations in local coolant flows were large. The local coolant flow variations ranged from 8 to 75 percent, and calculated metal temperature variations ranged from 8 to 60 K (15 to 180 F).

Yeh, F. C.; Meitner, P. L.; Russell, L. M.

1975-01-01

3

Predicted inlet gas temperatures for tungsten fiber reinforced superalloy turbine blades  

NASA Technical Reports Server (NTRS)

Tungsten fiber reinforced superalloy composite (TFRS) impingement cooled turbine blade inlet gas temperatures were calculated taking into account material spanwise strength, thermal conductivity, material oxidation resistance, fiber-matrix interaction, and coolant flow. Measured values of TFRS thermal conductivities are presented. Calculations indicate that blades made of 30 volume percent fiber content TFRS having a 12,000 N-m/kg stress-to-density ratio while operating at 40 atmospheres and a 0.06 coolant flow ratio could permit a turbine blade inlet gas temperature of over 1900K. This is more than 150K greater than similar superalloy blades.

Winsa, E. A.; Westfall, L. J.; Petrasek, D. W.

1978-01-01

4

Cooled-turbine aerodynamic performance prediction from reduced primary to coolant total-temperature-ratio results  

NASA Technical Reports Server (NTRS)

The prediction of the cooled aerodynamic performance, for both stators and turbines, at actual primary to coolant inlet total temperature ratios from the results obtained at a reduced total temperature ratio is described. Theoretical and available experimental results were compared for convection film and transpiration cooled stator vanes and for a film cooled, single stage core turbine. For these tests the total temperature ratio varied from near 1.0 to about 2.7. The agreement between the theoretical and the experimental results was, in general, reasonable.

Goldman, L. J.

1976-01-01

5

Stagnation region gas film cooling: Effects of dimensionless coolant temperature  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to mode the film cooling performance for a turbine vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio and dimensionless coolant temperature with free stream-to-wall temperature ratio approximately 1.7 and Re sub D = 90000. the cylindrical test surface was instrumented with miniature heat flux gages and wall thermocouples to determine the percentage reduction in the Stanton number as a function of the distance downstream from injection (x/d sub 0) and the location between adjacent holes (z/S). Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, from stagnation using a hole spacing ratio of S/d = 5. The film coolant was injected with T sub c T sub w with a dimensionless coolant temperature in the range 1.18 or equal to theta sub c or equal to 1.56. The data for local Stanton Number Reduction (SNR) showed a significant increase in SNR as theta sub c was increased above 1.0.

Bonnice, M. A.; Lecuyer, M. R.

1983-01-01

6

Stagnation region gas film cooling: Effects of dimensionless coolant temperature  

NASA Astrophysics Data System (ADS)

An experimental investigation was conducted to mode the film cooling performance for a turbine vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio and dimensionless coolant temperature with free stream-to-wall temperature ratio approximately 1.7 and Re sub D = 90000. the cylindrical test surface was instrumented with miniature heat flux gages and wall thermocouples to determine the percentage reduction in the Stanton number as a function of the distance downstream from injection (x/d sub 0) and the location between adjacent holes (z/S). Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, from stagnation using a hole spacing ratio of S/d = 5. The film coolant was injected with T sub c T sub w with a dimensionless coolant temperature in the range 1.18 or equal to theta sub c or equal to 1.56. The data for local Stanton Number Reduction (SNR) showed a significant increase in SNR as theta sub c was increased above 1.0.

Bonnice, M. A.; Lecuyer, M. R.

1983-07-01

7

Inductive modeling for predicting maximum turbine inlet temperatures  

Microsoft Academic Search

Engine, aircraft, and environmental data collected during the operation of eight GE TF-39 engines installed in US Air Force C-5 Galaxy cargo aircraft were used in a two part program to demonstrate, test, and evaluate the capability of polynomial neural networks (PNNs) to predict maximum turbine inlet temperatures (Max TITs). Input parameters were measured before, during, and shortly after the

Michel A. King; William T. Scherer

1994-01-01

8

Effect of pressure ratio and inlet pressure on performance of experimental gas turbine at inlet temperature of 800 R  

NASA Technical Reports Server (NTRS)

An experimental gas turbine was operated over a range of blade-jet speed ratios, total pressure ratios, and inlet total pressures at a constant inlet temperature of 800 R. Peak over-all efficiencies were obtained at blade-jet speed ratios from 0.525 to 0.575 for all runs. The variation in peak efficiency with inlet pressure and pressure ratio was of small magnitude for the conditions investigated.

Kohl, Robert C; Larkin, Robert G

1948-01-01

9

Ultra-lean combustion at high inlet temperatures  

NASA Technical Reports Server (NTRS)

Combustion at inlet air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12 cm diameter test section at a pressure of 2.5 x 10 to the 5th power Pa, with reference velocities of 32 to 60 m/sec and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple source fuel injector. Unburned hydrocarbons emissions were negligible for all test conditions. Nitrogen oxides emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet air temperatures higher than 1150 K, and residence times greater than 4.3 microseconds.

Anderson, D. N.

1981-01-01

10

Self-actuated nuclear reactor shutdown system using induction pump to facilitate sensing of core coolant temperature  

DOEpatents

A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly and in flow communication with the inlet thereof. The pump nozzle is operable to create an upward driving flow of primary coolant through the pump diffuser and then to the absorber bundles. The upward driving flow of primary coolant, in turn, creates a suction head within the outer flow channel of the top nozzle and thereby an auxiliary downward flow of the heated coolant portion exiting from the upper end of the adjacent fuel assemblies through the outer flow channel to the pump nozzle via the outer flow passage of the latching mechanism and an annular space between the outer and inner spaced ducts of the control assembly housing. The temperature of the heated coolant exiting from the adjacent fuel assemblies can thereby be sensed directly by the temperature sensitive magnetic material in the latching mechanism.

Sievers, Robert K. (N. Huntingdon, PA); Cooper, Martin H. (Churchill, PA); Tupper, Robert B. (Greensburg, PA)

1987-01-01

11

Development of a prototype automatic controller for liquid cooling garment inlet temperature  

NASA Technical Reports Server (NTRS)

The development of a computer control of a liquid cooled garment (LCG) inlet temperature is descirbed. An adaptive model of the LCG is used to predict the heat-removal rates for various inlet temperatures. An experimental system that contains a microcomputer was constructed. The LCG inlet and outlet temperatures and the heat exchanger outlet temperature form the inputs to the computer. The adaptive model prediction method of control is successful during tests where the inlet temperature is automatically chosen by the computer. It is concluded that the program can be implemented in a microprocessor of a size that is practical for a life support back-pack.

Weaver, C. S.; Webbon, B. W.; Montgomery, L. D.

1982-01-01

12

Comparison of Calculated and Experimental Temperatures and Coolant Pressure Losses for a Cascade of Small Air-Cooled Turbine Rotor Blades  

NASA Technical Reports Server (NTRS)

Average spanwise blade temperatures and cooling-air pressure losses through a small (1.4-in, span, 0.7-in, chord) air-cooled turbine blade were calculated and are compared with experimental nonrotating cascade data. Two methods of calculating the blade spanwise metal temperature distributions are presented. The method which considered the effect of the length-to-diameter ratio of the coolant passage on the blade-to-coolant heat-transfer coefficient and assumed constant coolant properties based on the coolant bulk temperature gave the best agreement with experimental data. The agreement obtained was within 3 percent at the midspan and tip regions of the blade. At the root region of the blade, the agreement was within 3 percent for coolant flows within the turbulent flow regime and within 10 percent for coolant flows in the laminar regime. The calculated and measured cooling-air pressure losses through the blade agreed within 5 percent. Calculated spanwise blade temperatures for assumed turboprop engine operating conditions of 2000 F turbine-inlet gas temperature and flight conditions of 300 knots at a 30,000-foot altitude agreed well with those obtained by the extrapolation of correlated experimental data of a static cascade investigation of these blades.

Stepka, Francis S

1958-01-01

13

Redistribution of an inlet temperature distortion in an axial flow turbine stage  

Microsoft Academic Search

The results of an experimental program aimed at determining the extent of the redistribution of an inlet temperature distortion in an axial flow turbine stage are presented. The program was conducted in a large-scale, low speed, single stage turbine where air, seeded with CO2 was introduced at one circumferential location upstream of the inlet guide vane. The migration of the

T. L. Butler; O. P. Sharma; H. D. Joslyn; R. P. Dring

1986-01-01

14

Effects of Temperature and Inlet Concentration on Acetone Biofiltration in a Composite Bead Biofilter  

Microsoft Academic Search

In this study, the effects of temperature and inlet concentration on acetone biofiltration in a composite bead biofilter were\\u000a investigated. Both microbial growth rate and biochemical reaction rate would be inhibited with increasing average inlet concentration.\\u000a The inhibitive effect was more pronounced at higher operation temperature for microbial growth rate, and it was more pronounced\\u000a at lower operation temperature for

Wu-Chung Chan; Liang-Yuan Chang

15

Experimental Investigation of an Air-Cooled Turbine Operating in a Turbojet Engine at Turbine Inlet Temperatures up to 2500 F  

NASA Technical Reports Server (NTRS)

An experimental investigation was made of an air-cooled turbine at average turbine inlet temperatures up to 2500 F. A modified production-model 12-stage axial-flow-compressor turbojet engine operating in a static sea-level stand was used as the test vehicle. The modifications to the engine consisted of the substitution of special combustor and turbine assemblies and double-walled exhaust ducting for the standard parts of the engine. All of these special parts were air-cooled to withstand the high operating temperatures of the investigation. The air-cooled turbine stator and rotor blades were of the corrugated-insert type. Leading-edge tip caps were installed on the rotor blades to improve leading-edge cooling by diverting the discharge of coolant to regions of lower gas pressure toward the trailing edge of the blade tip. Caps varying in length from 0.15- to 0.55-chord length were used in an attempt to determine the optimum cap length for this blade. The engine was operated over a range of average turbine inlet temperatures from about 1600 to about 2500 F, and a range of average coolant-flow ratios of 0.012 to 0.065. Temperatures of the air-cooled turbine rotor blades were measured at all test conditions by the use of thermocouples and temperature-indicating paints. The results of the investigation indicated that this type of blade is feasible for operation in turbojet engines at the average turbine inlet temperatures and stress levels tested(maximums of 2500 F and 24,000 psi, respectively). An average one-third-span blade temperature of 1300 F could be maintained on 0.35-chord tip cap blades with an average coolant-flow ratio of about 0.022 when the average turbine inlet temperature was 2500 F and cooling-air temperature was about 260 F. All of the leading-edge tip cap lengths improved the cooling of the leading-edge region of the blades, particularly at low average coolant-flow ratios. At high gas temperatures, such parts as the turbine stator and the combustor liners are likely to be as critical as the turbine rotor blades.

Cochran, Reeves P.; Dengler, Robert P.

1961-01-01

16

Response of a small-turboshaft-engine compression system to inlet temperature distortion  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted into the response of a small-turboshaft-engine compression system to steady-state and transient inlet temperature distortions. Transient temperature ramps range from less than 100 K/sec to above 610 K/sec and generated instantaneous temperatures to 420 K above ambient. Steady-state temperature distortion levels were limited by the engine hardware temperature list. Simple analysis of the steady-state distortion data indicated that a particle separator at the engine inlet permitted higher levels of temperature distortion before onset of compressor surge than would be expected without the separator.

Biesiadny, T. J.; Klann, G. A.; Little, J. K.

1984-01-01

17

Measurement of the Coolant Channel Temperatures and Pressures of a Cooled Radial-Inflow Turbine  

NASA Technical Reports Server (NTRS)

Instrumentation has been installed on the surface of a cooled radial-inflow turbine. Thermocouples and miniature integrated sensor pressure transducers were installed to measure steady state coolant temperatures, blade wall temperatures, and coolant pressures. These measurements will eventually be used to determine the heat transfer characteristics of the rotor. This paper will describe the procedures used to install and calibrate the instrumentation and the testing methods followed. A limited amount of data will compare the measured values to the predicted values.

Dicicco, L. Danielle; Nowlin, Brent C.; Tirres, Lizet

1994-01-01

18

Method of and apparatus for removing silicon from a high temperature sodium coolant  

DOEpatents

A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

Yunker, Wayne H. (Richland, WA); Christiansen, David W. (Kennewick, WA)

1987-01-01

19

Effect of spatial inlet temperature and pressure distortion on turbofan engine stability  

NASA Technical Reports Server (NTRS)

The effects of circumferential and radial inlet temperature distortion, circumferential pressure distortion, and combined temperature and pressure distortion on the stability of an advanced turbofan engine were investigated experimentally at simulated altitude conditions. With circumferential and radial inlet temperature distortion, a flow instability generated by the fan operating near stall caused the high-pressure compressor to surge at, or near, the same time as the fan. The effect of combined distortion was dependent on the relative location of the high-temperature and low-pressure regions; high-pressure compressor stalls occurred when the regions coincided, and fan stalls occurred with the regions separated.

Mehalic, Charles M.

1988-01-01

20

Apparatus and Method for Measuring Air Temperature Ahead of an Aircraft for Controlling a Variable Inlet/Engine Assembly  

NASA Technical Reports Server (NTRS)

The apparatus and method employ remote sensing to measure the air temperature a sufficient distance ahead of the aircraft to allow time for a variable inlet/engine assembly to be reconfigured in response to the measured temperature, to avoid inlet unstart and/or engine compressor stall. In one embodiment, the apparatus of the invention has a remote sensor for measuring at least one air temperature ahead of the vehicle and an inlet control system for varying the inlet. The remote sensor determines a change in temperature value using at least one temperature measurement and prior temperature measurements corresponding to the location of the aircraft. The control system uses the change in air temperature value to vary the inlet configuration to maintain the position of the shock wave during the arrival of the measured air in the inlet. In one embodiment, the method of the invention includes measuring at least one air temperature ahead of the vehicle, determining an air temperature at the vehicle from prior air temperature measurements, determining a change in temperature value using the air temperature at the vehicle and the at least one air temperature measurement ahead of the vehicle, and using the change in temperature value to-reposition the airflow inlet, to cause the shock wave to maintain substantially the same position within the inlet as the airflow temperature changes within the inlet.

Gary, Bruce L. (Inventor)

2001-01-01

21

Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles  

NASA Astrophysics Data System (ADS)

Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

Maqsood, Omar Shahzada

22

Performance of 19XB-2A Gas Turbine. 1; Effect of Pressure Ratio and Inlet Pressure on Turbine Performance for an Inlet Temperature of 800 degree R  

NASA Technical Reports Server (NTRS)

An investigation of the 19XB-2A gas turbine is being conducted at the Cleveland laboratory to determine the effect on turbine performance of various inlet pressures, inlet temperatures, pressure ratios, and wheel speeds. The engine of which this turbine is a component is designed to operate at an air flow of 30 pounds per second at a compressor rotor speed of 17,000 rpm at sea-level conditions. At these conditions the total-pressure ratio is 2.08 across the turbine and the turbine inlet total temperature is 2000 degrees R. Runs have been made with turbine inlet total pressures of 20, 30, 40, and 45 inches of mercury absolute for a constant total pressure ratio across the turbine of 2.40, the maximum value that could be obtained. Additional runs have been made with total pressure ratios of 1.50 and 2.00 at an inlet total pressure of 45 inches of mercury absolute. All runs were made with an inlet total temperature of 800 degrees R over a range of corrected turbine wheel speeds from 40 to 150 percent of the corrected speed at the design point. The turbine efficiencies at these conditions are presented.

Kohl, Robert C.; Larkin, Robert G.

1946-01-01

23

Analysis of a water-coolant leak into a very high-temperature vitrification chamber.  

SciTech Connect

A coolant-leakage incident occurred during non-radioactive operation of the Plasma Hearth Process waste-vitrification development system at Argonne National Laboratory when a stray electric arc ruptured az water-cooling jacket. Rapid evaporation of the coolant that entered the very high-temperature chamber pressurized the normally sub-atmospheric system above ambient pressure for over 13 minutes. Any positive pressurization, and particularly a lengthy one, is a safety concern since this can cause leakage of contaminants from the system. A model of the thermal phenomena that describe coolant/hot-material interactions was developed to better understand the characteristics of this type of incident. The model is described and results for a variety of hypothetical coolant-leak incidents are presented. It is shown that coolant leak rates above a certain threshold will cause coolant to accumulate in the chamber, and evaporation from this pool can maintain positive pressure in the system long after the leak has been stopped. Application of the model resulted in reasonably good agreement with the duration of the pressure measured during the incident. A closed-form analytic solution is shown to be applicable to the initial leak period in which the peak pressures are generated, and is presented and discussed.

Felicione, F. S.

1998-06-11

24

Afterburner performance of film-vaporizing V-gutters for inlet temperatures up to 1255 K  

NASA Technical Reports Server (NTRS)

Combustion tests of five variations of an integral, spray-bar - flameholder combination were conducted in a 0.49-m-diameter duct. Emphasis was on low levels of augmentation. Fuel impinged on guide plates, mixed with a controlled amount of inlet air, vaporized, and was guided into the V-gutter wake. Combustor length was 0.92 m. Good performance was demonstrated at fuel-air ratios less than 0.025 for inlet temperatures of 920 to 1255 K. Maximum combustion efficiency occured in the vicinity of fuel-air ratios of 0.02 and was 92 to 100 percent, depending on the inlet temperature. Lean blowout fuel-air ratios were in the vicinity of 0.005. Improvements in rich-limit blowout resulted from enlarging the guide-flow passageway areas. Other means of extending the operating range are suggested. A simplified afterburner concept for application to advanced engines is described.

Branstetter, J. R.; Reck, G. M.

1973-01-01

25

Method of and apparatus for removing silicon from a high temperature sodium coolant  

DOEpatents

This patent discloses a method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

Yunker, W.H.; Christiansen, D.W.

1983-11-25

26

Load following capability of CANDLE reactor by adjusting coolant operation condition  

SciTech Connect

The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and {sup 208}Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

Sekimoto, Hiroshi; Nakayama, Sinsuke [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-17, Ookayama, Meguro-ku 152-8550 (Japan)

2012-06-06

27

Load following capability of CANDLE reactor by adjusting coolant operation condition  

NASA Astrophysics Data System (ADS)

The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and 208Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

Sekimoto, Hiroshi; Nakayama, Sinsuke

2012-06-01

28

Computing Flows Of Coolants In Turbomachines  

NASA Technical Reports Server (NTRS)

Coolant Passage Flow (CPF) computer code developed to predict accurately coolant flow and heat transfer inside turbomachinery cooling passages (either radial or axial blading). Computes flow in one-inlet/one-outlet passage of any shape. Calculates rate of flow of coolant, temperature, pressure, velocity, and heat-transfer coefficients along passage. Integrates one-dimensional momentum and energy equations along defined flow path, taking into account change in area, addition or subtraction of mass, pumping, friction, and transfer of heat. Written in FORTRAN IV.

Meitner, P. L.

1994-01-01

29

Effect of Steady-State Temperature Distortion on Inlet Flow to a High-Bypass-Ratio Turbofan Engine  

NASA Technical Reports Server (NTRS)

The effects of circumferential inlet temperature distortion on the flow characteristics between a distortion generator and a high bypass ratio turbofan engine and through its compression system were evaluated to support the effort to generate analytical models. The flow characteristics are defined by the inlet duct, the flow angles, and the total temperature, total pressure, and static pressure profiles in the inlet duct and through the fan and compressor. The effects of Reynolds number, rotor speed, and distortion extent are also considered.

Soeder, R. H.; Mehalic, C. M.; Stancik, K.

1985-01-01

30

Effects of Non-Uniform Inlet Temperature Distribution on High-Pressure Turbine Blade Loading  

NASA Astrophysics Data System (ADS)

The effects of a non-uniform inlet field on the performance of a commercial, transonic, single-stage, high-pressure, axial turbine with a curved inlet duct have been investigated numerically by solving the unsteady Reynolds-averaged Navier-Stokes equations with the shear stress transport (SST) turbulence model. By adjusting the alignment of the experimentally-based inlet temperature field with respect to the stator vanes, two clocking configurations were generated: a Vane-Impinging (VI) case, in which each hot streak impinged on a vane and a Mid-Pitch (MP) case, in which each hot streak passed between two vanes. An additional case with a purely radial (PR) variation of inlet temperature was also investigated. In the VI case, it was observed that, as the hot streaks impinged on the stator vanes, they spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. In the MP case, the hot streaks were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration.

Smith, Craig I.; Chang, Dongil; Tavoularis, Stavros

2012-09-01

31

Temperature profile development in turbulent mixing of coolant jets with a confined hot cross flow  

Microsoft Academic Search

The mixing of coolant air jets with the hot gas exiting the primary zone is of major importance to the combustor exit temperature profile. Geometry and momentum flux ratios are the dominant parameters. A theoretical and experimental study of single as well as opposite wall jet injection into a hot cross flow reveals the applicability and limitations of existing correlations.

S. L. K. Wittig; O. M. F. Elbahar; B. E. Noll

1983-01-01

32

Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles  

SciTech Connect

This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from test data at 900 rpm. They are approximately 15 kW with 103 C coolant and 20 kW with 50 C coolant. To avoid this 25% drop1 in continuous power, design changes for improved heat dissipation and carefully managed changes in allowable thermal limits would be required in the hybrid subsystems. This study is designed to identify the technical barriers that potentially exist in moving to a high-temperature cooling loop prior to addressing the actual detailed design. For operation at a significantly higher coolant temperature, there were component-level issues that had to be addressed in this study. These issues generally pertained to the cost and reliability of existing or near-term components that would be suitable for use with the 105 C coolant. The assessed components include power electronic devices/modules such as diodes and insulated-gate bipolar transistors (IGBTs), inverter-grade high-temperature capacitors, permanent magnets (PM), and motor-grade wire insulation. The need for potentially modifying/resizing subassemblies such as inverters, motors, and heat exchangers was also addressed in the study. In order to obtain pertinent information to assist ORNL researchers address the thermal issues at the component, module, subassembly, and system levels, pre-existing laboratory test data conducted at varying temperatures was analyzed in conjunction with information obtained from technical literature searches and industry sources.

Staunton, Robert H [ORNL; Hsu, John S [ORNL; Starke, Michael R [ORNL

2006-09-01

33

Effects of Coolant Temperature Changes on Reactivity for Various Coolants in a Liquid Salt Cooled Very High Temperature Reactor (LS-VHTR)  

SciTech Connect

The purpose of this study is to perform an investigation into the relative merit of various salts and salt compounds being considered for use as coolants in the liquid salt cooled very high temperature reactor platform (LS-VHTR). Most of the non-nuclear properties necessary to evaluate these salts are known, but the neutronic characteristics important to reactor core design are still in need of a more extensive examination. This report provides a two-fold approach to further this investigation. First, a list of qualifying salts is assembled based upon acceptable non-nuclear properties. Second, the effect on system reactivity for a secondary system transient or an off-normal or accident condition is examined for each of these salt choices. The specific incident to be investigated is an increase in primary coolant temperature beyond normal operating parameters. In order to perform the relative merit comparison of each candidate salt, the System Temperature Coefficient of Reactivity is calculated for each candidate salt at various state points throughout the core burn history. (author)

Casino, William A. Jr. [AREVA - Framatome ANP, 3315 Old Forest Road OF-15, P.O. Box 10935, Lynchburg, VA 24506-0935 (United States)

2006-07-01

34

Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control  

NASA Technical Reports Server (NTRS)

A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

Anderson, D. N.

1978-01-01

35

A master-follower type distributed scheme for reactor inlet temperature control  

Microsoft Academic Search

This paper describes the implementation of a computer-based controller for regulating reactor inlet temperature in a pool-type power plant. The elements of the control system are organized in a master-follower hierarchical architecture that takes advantage of existing in-plant hardware and software to minimize the need for plant modifications. Low level control algorithms are executed on existing local digital controllers (followers)

H. E. Garcia; E. M. Dean; R. B. Vilim

1995-01-01

36

Water temperature of streams in the Cook Inlet basin, Alaska, and implications of climate change  

USGS Publications Warehouse

Water-temperature data from 32 sites in the Cook Inlet Basin, south-central Alaska, indicate various trends that depend on watershed characteristics. Basins with 25 percent or more of their area consisting of glaciers have the coldest water temperatures during the open-water season, mid-May to mid-October. Streams and rivers that drain lowlands have the warmest water temperatures. A model that uses air temperature as input to predict water temperature as output was utilized to simulate future trends in water temperature based on increased air temperatures due to climate warming. Based on the Nash-Sutcliffe coefficient, the model produced acceptable results for 27 sites. For basins with more than 25 percent glacial coverage, the model was not as accurate. Results indicate that 15 sites had a predicted water-temperature change of 3 degrees Celsius or more, a magnitude of change that is considered significant for the incidence of disease in fish populations.

Kyle, Rebecca E.; Brabets, Timothy P.

2001-01-01

37

The effect of inlet temperature and pressure distortion on turbojet performance  

NASA Technical Reports Server (NTRS)

The effects on stability of steady-state, 180 degree extent circumferential distortions of inlet total temperature and pressure were experimentally determined for a turbojet engine. Results for both individual and combined temperature and pressure distortions are presented showing the losses incurred in stall pressure ratio and are compared with results predicted using a simplified parallel compressor model. The loss due to combined distortions was dependent upon the relative orientation between the low pressure and high temperature regions. Reasonable agreement was achieved between the predicted and observed loss in stall pressure ratio when based on a constant corrected speed relationship.

Braithwaite, W. M.; Graber, E. J., Jr.; Mehalic, C. M.

1973-01-01

38

The effects of inlet temperature and pressure distortion on turbojet performance  

NASA Technical Reports Server (NTRS)

The effects on stability of steady-state, 180 degree extent circumferential distortions of inlet total temperature and pressure were experimentally determined for a turbojet engine. Results for both individual and combined temperature and pressure distortions are presented showing the losses incurred in stall pressure ratio and are compared with results predicted using a simplified parallel compressor model. The loss due to combined distortions was dependent upon the relative orientation between the low pressure and high temperature regions. Reasonable agreement was achieved between the predicted and observed loss in stall pressure ratio when based on a constant corrected speed relationship.

Braithwaite, W. M.; Graber, E. J., Jr.; Mehalic, C. M.

1973-01-01

39

Coolant Topology Options for High Temperature Superconducting Transmission and Distribution Systems  

NASA Astrophysics Data System (ADS)

This paper investigates coolant topologies for High Temperature Superconducting (HTS) transmission and distribution cable systems. We explore options that allow for flexibility of operation, low temperature rise in the superconductor and low refrigerator power consumption. Topologies for cooling the cryostat and HTS in long-distance electric power transmission systems are explored. For transmission, the goal is to achieve long spans between cooling stations along the transmission line, and low power consumption. For HTS distribution systems, the issue is cooling the superconductor and the current leads and the goals are to minimize the power consumption and to prevent excessive heating of the superconductor. Means are explored to cool distribution systems where cryogenic loads are dominated by current lead loss. Use of multiple fluids or multiple coolant circuits of the same fluid to decrease the energy ingress in the low temperature environment is described. Potential alternative coolants are proposed. We show that it is possible to reduce electrical consumption by about a factor of 2, while also decreasing the temperature rise of the superconductor.

Bromberg, L.; Michael, P. C.; Minervini, J. V.; Miles, C.

2010-04-01

40

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

41

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

42

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

43

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

44

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

45

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

46

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2013-07-01

47

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

48

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

49

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2010-07-01

50

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

51

40 CFR 60.1815 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1815 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

52

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2014-07-01

53

40 CFR 60.1325 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 60.1325 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2012-07-01

54

40 CFR 62.15270 - How do I monitor the temperature of flue gases at the inlet of my particulate matter control device?  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false How do I monitor the temperature of flue gases at the inlet of my particulate... § 62.15270 How do I monitor the temperature of flue gases at the inlet of my particulate...a device to continuously measure the temperature of the flue gas stream at the inlet...

2011-07-01

55

Experimental research of temperature and velocity fields in high-temperature flow of liquid heavy metal coolant  

SciTech Connect

Presented are the results of experimental research of temperature and velocity fields for lead and lead-bismuth coolant flows in channels having circular and annular cross sections under varying oxygen content in the coolant and varying characteristics of insulating coatings. Tests are performed under the following operating conditions: (1) lead-bismuth eutectic-temperature T = 400-520 Degree-Sign C, thermodynamic oxygen activity a = 10{sup -5}-10{sup 0}, average flow velocity of the coolant w = 0.12-1.84 m/s, value of magnetic induction B = 0-0.85 T, Reynolds number Re = (0.24-3.5) Multiplication-Sign 10{sup 5}, Hartmann number Ha = 0-500, and Peclet number Pe = 320-4600; (2) lead coolant-T = 400-550 Degree-Sign C, a = 10{sup -5}-10{sup 0}, w = 0.1-1.5 m/s, Re = (2.36-2.99) Multiplication-Sign 10{sup 5}, and Pe = 500-7000.

Besnosov, A. V., E-mail: ats@nntu.nnov.ru; Savinov, S. Yu., E-mail: Savinov.S@mail.ru; Novozhilova, O. O.; Antonenkov, M. A. [Nizhni Novgorod State Technical University (Russian Federation)

2011-12-15

56

On the dependence of the noise amplitude on the correlation length of inlet temperature fluctuations in PWRs  

E-print Network

effect Noise amplitude Moderator temperature fluctuation PWRs a b s t r a c t The dependence and technological processes, such as fluctuations in temperature, pressure, density, and displacement (movement. The effect of coolant temperature on the reactivity is ex- pressed via the Moderator Temperature Coefficient

Demazière, Christophe

57

Effect of inlet temperature and pressure on emissions from a premixing gas turbine primary zone combustor  

NASA Technical Reports Server (NTRS)

Experiments were conducted to determine the performance of a premixing prevaporizing gas turbine primary zone combustor design over a range of combustor inlet temperatures from 700 to 1000 K and a range of inlet pressures from 40 to 240 N/sq cm. The 1 meter long combustor could be operated at pressures up to and including 120 N/sq cm without autoignition in the premixing duct or flashback from the stabilized combustion zone. Autoignition occurred in the mixer tube at the 240 N/sq cm pressure level with an entrance temperature of 830 K and a mixer residence time of 4 msec. Measured NOx level, combustion inefficiency, and hydrocarbon emission index correlated well with adiabatic flame temperature. The NOx levels varied from approximately 0.2 to 2.0 g NO2/kg fuel at combustion inefficiencies from 4 to 0.04 percent, depending upon adiabatic flame temperature and pressure. Measured NOx levels were sensitive to pressure. Tests were made at equivalence ratios ranging from 0.35 to 0.65. The overall total pressure drop for the configuration varied slightly with reference velocity and equivalence ratio, but never exceeded 3 percent.

Roffe, G.

1976-01-01

58

The influence of the high-temperature coolant purification system at nuclear power stations equipped with VVER-1000 reactors on the formation of dose burdens  

NASA Astrophysics Data System (ADS)

It is shown that the effectiveness of using high-temperature filters for purifying the coolant at nuclear power stations equipped with VVER-1000 reactors is mainly determined by the precipitation constant of activated corrosion products dispersed in the coolant.

Gusev, B. A.; Krasnoperov, V. M.

2011-05-01

59

Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications  

SciTech Connect

Corrosion of ferritic steels in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such a beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li{sub 2}BeF{sub 4}) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. This paper also reports electrochemical impedance spectroscopy of steels at their corrosion potentials in high-temperature molten salt environments, with the complex impedance spectra interpreted in terms of the interfacial charge transfer resistance and capacitance, as well as the electrolyte conductivity. Such in situ measurement techniques provide valuable insight into the degradation of materials under realistic conditions.

Farmer, J; El-Dasher, B; de Caro, M S; Ferreira, J

2008-11-25

60

Inlet nozzle assembly  

DOEpatents

An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

Christiansen, David W. (Kennewick, WA); Karnesky, Richard A. (Richland, WA); Precechtel, Donald R. (Richland, WA); Smith, Bob G. (Richland, WA); Knight, Ronald C. (Richland, WA)

1987-01-01

61

The comparative performance of an aviation engine at normal and high inlet air temperatures  

NASA Technical Reports Server (NTRS)

This report presents some results obtained during an investigation to determine the effect of high inlet air temperature on the performance of a Liberty 12 aviation engine. The purpose of this investigation was to ascertain, for normal service carburetor adjustments and a fixed ignition advance, the relation between power and temperature for the range of carburetor air temperatures that may be encountered when supercharging to sea level pressure at altitudes of over 20,000 feet and without intercooling when using plain aviation gasoline and mixtures of benzol and gasoline. The results show that for the conditions of test, both the brake and indicated power decrease with increase in air temperature at a faster rate than given by the theoretical assumption that power varies inversely as the square root of the absolute temperature. On a brake basis, the order of the difference in power for a temperature difference of 120 degrees F. Is 3 to 5 per cent. The observed relation between power and temperature when using the 30-70 blend was found to be linear. But, although these differences are noted, the above theoretical assumption may be considered as generally applicable except where greater precision over a wide range of temperatures is desired, in which case it appears necessary to test the particular engine under the given conditions. (author)

Gardiner, Arthur W; Schey, Oscar W

1928-01-01

62

Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR)  

SciTech Connect

The Advanced High-Temperature Reactor (AHTR) is a novel reactor design that utilizes the graphite-matrix high-temperature fuel of helium-cooled reactors, but provides cooling with a high-temperature fluoride salt. For applications at temperatures greater than 900 C the AHTR is also referred to as a Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR). This report provides an assessment of candidate salts proposed as the primary coolant for the AHTR based upon a review of physical properties, nuclear properties, and chemical factors. The physical properties most relevant for coolant service were reviewed. Key chemical factors that influence material compatibility were also analyzed for the purpose of screening salt candidates. Some simple screening factors related to the nuclear properties of salts were also developed. The moderating ratio and neutron-absorption cross-section were compiled for each salt. The short-lived activation products, long-lived transmutation activity, and reactivity coefficients associated with various salt candidates were estimated using a computational model. Table A presents a summary of the properties of the candidate coolant salts. Certain factors in this table, such as melting point, vapor pressure, and nuclear properties, can be viewed as stand-alone parameters for screening candidates. Heat-transfer properties are considered as a group in Sect. 3 in order to evaluate the combined effects of various factors. In the course of this review, it became apparent that the state of the properties database was strong in some areas and weak in others. A qualitative map of the state of the database and predictive capabilities is given in Table B. It is apparent that the property of thermal conductivity has the greatest uncertainty and is the most difficult to measure. The database, with respect to heat capacity, can be improved with modern instruments and modest effort. In general, ''lighter'' (low-Z) salts tend to exhibit better heat transfer and nuclear performance metrics. Lighter salts also tend to have more favorable (larger) moderating ratios, and thus should have a more favorable coolant-voiding behavior in-core. Heavy (high-Z) salts tend to have lower heat capacities and thermal conductivities and more significant activation and transmutation products. However, all of the salts are relatively good heat-transfer agents. A detailed discussion of each property and the combination of properties that served as a heat-transfer metric is presented in the body of this report. In addition to neutronic metrics, such as moderating ratio and neutron absorption, the activation properties of the salts were investigated (Table C). Again, lighter salts tend to have more favorable activation properties compared to salts with high atomic-number constituents. A simple model for estimating the reactivity coefficients associated with a reduction of salt content in the core (voiding or thermal expansion) was also developed, and the primary parameters were investigated. It appears that reasonable design flexibility exists to select a safe combination of fuel-element design and salt coolant for most of the candidate salts. Materials compatibility is an overriding consideration for high-temperature reactors; therefore the question was posed whether any one of the candidate salts was inherently, or significantly, more corrosive than another. This is a very complex subject, and it was not possible to exclude any fluoride salts based on the corrosion database. The corrosion database clearly indicates superior container alloys, but the effect of salt identity is masked by many factors which are likely more important (impurities, redox condition) in the testing evidence than salt identity. Despite this uncertainty, some reasonable preferences can be recommended, and these are indicated in the conclusions. The reasoning to support these conclusions is established in the body of this report.

Williams, D.F.

2006-03-24

63

The effect of feed solids concentration and inlet temperature on the flavor of spray dried whey protein concentrate.  

PubMed

Previous research has demonstrated that unit operations in whey protein manufacture promote off-flavor production in whey protein. The objective of this study was to determine the effects of feed solids concentration in liquid retentate and spray drier inlet temperature on the flavor of dried whey protein concentrate (WPC). Cheddar cheese whey was manufactured, fat-separated, pasteurized, bleached (250 ppm hydrogen peroxide), and ultrafiltered (UF) to obtain WPC80 retentate (25% solids, wt/wt). The liquid retentate was then diluted with deionized water to the following solids concentrations: 25%, 18%, and 10%. Each of the treatments was then spray dried at the following temperatures: 180 °C, 200 °C, and 220 °C. The experiment was replicated 3 times. Flavor of the WPC80 was evaluated by sensory and instrumental analyses. Particle size and surface free fat were also analyzed. Both main effects (solids concentration and inlet temperature) and interactions were investigated. WPC80 spray dried at 10% feed solids concentration had increased surface free fat, increased intensities of overall aroma, cabbage and cardboard flavors and increased concentrations of pentanal, hexanal, heptanal, decanal, (E)2-decenal, DMTS, DMDS, and 2,4-decadienal (P < 0.05) compared to WPC80 spray dried at 25% feed solids. Product spray dried at lower inlet temperature also had increased surface free fat and increased intensity of cardboard flavor and increased concentrations of pentanal, (Z)4-heptenal, nonanal, decanal, 2,4-nonadienal, 2,4-decadienal, and 2- and 3-methyl butanal (P < 0.05) compared to product spray dried at higher inlet temperature. Particle size was higher for powders from increased feed solids concentration and increased inlet temperature (P < 0.05). An increase in feed solids concentration in the liquid retentate and inlet temperature within the parameters evaluated decreased off-flavor intensity in the resulting WPC80. PMID:24329978

Park, Curtis W; Bastian, Eric; Farkas, Brian; Drake, MaryAnne

2014-01-01

64

Effect of steady-state temperature distortion and combined distortion on inlet flow to a turbofan engine  

NASA Technical Reports Server (NTRS)

Flow angle, static pressure, total temperature and total pressure were measured in the inlet duct upstream of a turbofan engine operating with temperature distortion or combined pressure-temperature distortion. Such measurements are useful in the evaluation of analytical models of inlet distortion. A rotating gaseous-hydrogen burner and a circumferential 180 degrees-extent screen configuration mounted on a rotatable assembly generated the distortions. Reynolds number index was maintained at 0.5 and engine corrected low-rotor speeds were held at 6000 and 8600 rpm. The measurements showed that at the entrance to the engine, flow angle was largest in the hub region. As flow approached the engine, yaw angle (circumferential variation) increased and pitch angle (radial variation) decreased. The magnitude of static-pressure distortion measured along the inlet-duct and extended bullet nose walls increased exponentially as flow approached the engine.

Soeder, R. H.; Bobula, G. A.

1979-01-01

65

Effect of Fuel-Air Ratio, Inlet Temperature, and Exhaust Pressure on Detonation  

NASA Technical Reports Server (NTRS)

An accurate determination of the end-gas condition was attempted by applying a refined method of analysis to experimental results. The results are compared with those obtained in Technical Report no. 655. The experimental technique employed afforded excellent control over the engine variables and unusual cyclic reproducibility. This, in conjunction with the new analysis, made possible the determination of the state of the end-gas at any instant to a fair degree of precision. Results showed that for any given maximum pressure the maximum permissible end-gas temperature increased as the fuel-air ratio was increased. The tendency to detonate was slightly reduced by an increase in residual gas content resulting from an increase in exhaust backpressure with inlet pressure constant.

Taylor, E S; Leary, W A; Diver, J R

1940-01-01

66

Effects of core excess reactivity and coolant average temperature on maximum operable time of NIRR-1 miniature neutron source reactor  

Microsoft Academic Search

We appraised in this study the effects of core excess reactivity and average coolant temperature on the operable time of the Nigeria Research Reactor-1 (NIRR-1), which is a miniature neutron source reactor (MNSR). The duration of the reactor operating time and fluence depletion under different operation mode as well as change in core excess reactivity with temperature coefficient was investigated

Y. A. Ahmed; I. B. Mansir; I. Yusuf; G. I. Balogun; S. A. Jonah

2011-01-01

67

Evaluation of High Temperature Tensile and Creep Properties of Light Water Reactor Coolant Piping Materials for Severe Accident Analyses  

Microsoft Academic Search

It has been pointed out that the reactor coolant system piping could fail prior to the meltthrough of the reactor pressure vessel in a high pressure sequence of pressurized water reactor severe accidents. In order to apply to the evaluation of the piping failure which influences the subsequent accident progression, models for the strength of piping materials at high temperatures

Yuhei HARADA; Yu MARUYAMA; Akio MAEDA; Eiichi CHINO; Hiroaki SHIBAZAKI; Tamotsu KUDO; Akihide HIDAKA; Kazuichiro HASHIMOTO; Jun SUGIMOTO

2000-01-01

68

Transient Response of a Serpentine Finned-Tube Cross-Flow Heat Exchanger to a Step Change in Inlet Temperature  

Microsoft Academic Search

An analysis of the thermal response of a finned-tube, liquid-to-gas cross-flow heat exchanger due to a step change in the liquid inlet temperature is performed. Closed-form solutions for the liquid and gas temperatures as functions of space and time are obtained via the Laplace transform technique for both small and large arguments of the modified Bessel function of the first

S. Abdallah; S. Rooke

1997-01-01

69

Computer code for predicting coolant flow and heat transfer in turbomachinery  

NASA Technical Reports Server (NTRS)

A computer code was developed to analyze any turbomachinery coolant flow path geometry that consist of a single flow passage with a unique inlet and exit. Flow can be bled off for tip-cap impingement cooling, and a flow bypass can be specified in which coolant flow is taken off at one point in the flow channel and reintroduced at a point farther downstream in the same channel. The user may either choose the coolant flow rate or let the program determine the flow rate from specified inlet and exit conditions. The computer code integrates the 1-D momentum and energy equations along a defined flow path and calculates the coolant's flow rate, temperature, pressure, and velocity and the heat transfer coefficients along the passage. The equations account for area change, mass addition or subtraction, pumping, friction, and heat transfer.

Meitner, Peter L.

1990-01-01

70

Development of a coolant channel helium and nitrogen gas ratio sensor for a high temperature gas reactor  

SciTech Connect

To measure the changing gas composition of the coolant during a postulated High Temperature Gas Reactor (HTGR) accident, an instrument is needed. This instrument must be compact enough to measure the ratio of the coolant versus the break gas in an individual coolant channel. This instrument must minimally impact the fluid flow and provide for non-direct signal routing to allow minimal disturbance to adjacent channels. The instrument must have a flexible geometry to allow for the measurement of larger volumes such as in the upper or lower plenum of a HTGR. The instrument must be capable of accurately functioning through the full operating temperature and pressure of a HTGR. This instrument is not commercially available, but a literature survey has shown that building off of the present work on Capacitance Sensors and Cross-Capacitors will provide a basis for the development of the desired instrument. One difficulty in developing and instrument to operate at HTGR temperatures is acquiring an electrical conductor that will not melt at 1600 deg. C. This requirement limits the material selection to high temperature ceramics, graphite, and exotic metals. An additional concern for the instrument is properly accounting for the thermal expansion of both the sensing components and the gas being measured. This work covers the basic instrument overview with a thorough discussion of the associated uncertainty in making these measurements. (authors)

Cadell, S. R.; Woods, B. G. [Oregon State Univ., 116 Radiation Center, Corvallis, OR 97331 (United States)

2012-07-01

71

Effect of seasonal changes in use patterns and cold inlet water temperature on water-heating loads  

SciTech Connect

This paper presents long-term test data obtained in 20 commercial buildings and 16 residential sites. The information illustrates the effects of variations in hot water load determinants and the effect on energy use. It also is useful as a supplement to the load profiles presented in the ASHRAE Handbooks and other design references. The commercial facilities include supermarkets, fast-food restaurants, full-service restaurants, commercial kitchens, a motel, a nursing home, a hospital, a bakery, and laundry facilities. The residential sites ere selected to provide test sites with higher-than-average hot water use. They include 13 single-family detached residences, one 14-unit apartment building, and two apartment laundries. Test data are available at measurement intervals of 1 minute for the residential sites and 15 minutes for the commercial sites. Summary data in tabular and graphical form are presented for average daily volumetric hot water use and cold inlet water temperature. Measured cold inlet water temperature and volumetric hot water use figures are compared to values typically used for design and analysis. Conclusions are offered regarding the effect of cold water inlet temperature and variations in hot water use on water-heating load and energy use. Recommendations for the use of the information presented in water-heating system design, performance optimization, and performance analysis conclude the paper.

Abrams, D.W.; Shedd, A.C. [D.W. Abrams, P.E. and Associates, Atlanta, GA (United States)

1996-11-01

72

Inlet technology  

NASA Technical Reports Server (NTRS)

At hypersonic flight Mach numbers, particularly above Mo = 10, the inlet compression process is no longer adiabatic, real gas chemistry takes on extra importance, and the combined effects of entropy layer and viscous effects lead to highly nonuniform flow profile characteristics at the combustor entrance. Under such conditions, traditional inlet efficiency parameters can be unnecessarily cumbersome and/or lacking in the ability to appropriately characterize the inlet flow and to provide insight into propulsion system performance. Recent experience suggests that the use of inlet entropy increases inlet efficiency in hypersonic applications.

Kutschenreuter, Paul

1992-01-01

73

The Effect of Inlet Temperature and Pressure on the Efficiency of a Single-stage Impulse Turbine Having a 13.2-inch Pitch-line Diameter Wheel  

NASA Technical Reports Server (NTRS)

Efficiency tests have been conducted on a single-stage impulse turbine having a 13.2-inch pitch-line diameter wheel and a cast nozzle diaphram over a range of turbine speeds from 3000 to 17,000 rpm, pressure ratios from 1.5 to 5.0, inlet total temperatures from 1200 deg to 2000 deg R, and inlet total pressures from 18 to 59 inches of mercury absolute. The effect of inlet temperature and pressure on turbine efficiency for constant pressure ration and blade-to-jet speed ration is correlated against a factor derived from the equation for Reynolds number. The degree of correlation indicates that the change in turbine efficiency with inlet temperature and [ressure for constant pressure ration and blade-to-jet speed ration is principally a Reynolds number effect.

Chanes, Ernest R.; Carman, L. Robert

1945-01-01

74

Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement  

NASA Technical Reports Server (NTRS)

Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.

Lundin, Bruce T; Povolny, John H; Chelko, Louis J

1949-01-01

75

Transient simulation of coolant peak temperature due to prolonged fan and/or water pump operation after the vehicle is keyed-off  

NASA Astrophysics Data System (ADS)

Automotive designers should design a robust engine cooling system which works well in both normal and severe driving conditions. When vehicles are keyed-off suddenly after some distance of hill-climbing driving, the coolant temperature tends to increase drastically. This is because heat soak in the engine could not be transferred away in a timely manner, as both the water pump and cooling fan stop working after the vehicle is keyed-off. In this research, we aimed to visualize the coolant temperature trend over time before and after the vehicles were keyed-off. In order to prevent coolant temperature from exceeding its boiling point and jeopardizing engine life, a numerical model was further tested with prolonged fan and/or water pump operation after keying-off. One dimensional thermal-fluid simulation was exploited to model the vehicle's cooling system. The behaviour of engine heat, air flow, and coolant flow over time were varied to observe the corresponding transient coolant temperatures. The robustness of this model was proven by validation with industry field test data. The numerical results provided sensible insights into the proposed solution. In short, prolonging fan operation for 500 s and prolonging both fan and water pump operation for 300 s could reduce coolant peak temperature efficiently. The physical implementation plan and benefits yielded from implementation of the electrical fan and electrical water pump are discussed.

Pang, Suh Chyn; Masjuki, Haji Hassan; Kalam, Md. Abul; Hazrat, Md. Ali

2014-01-01

76

Investigation of X24C-2 10-Stage Axial-Flow Compressor. 2; Effect of Inlet-Air Pressure and Temperature of Performance  

NASA Technical Reports Server (NTRS)

Effect of inlet-air pressure and temperature on the performance of the X24-2 10-Stage Axial-Flow Compressor from the X24C-2 turbojet engine was evaluated. Speeds of 80, 89, and 100 percent of equivalent design speed with inlet-air pressures of 6 and 12 inches of mercury absolute and inlet-air temperaures of approximately 538 degrees, 459 degrees,and 419 degrees R ( 79 degrees, 0 degrees, and minus 40 degrees F). Results were compared with prior investigations.

Finger, Harold B.; Schum, Harold J.; Buckner, Howard Jr.

1947-01-01

77

Effect of inlet-air humidity, temperature, pressure, and reference Mach number on the formation of oxides of nitrogen in a gas turbine combustor  

NASA Technical Reports Server (NTRS)

Tests were conducted to determine the effect of inlet air humidity on the formation of oxides of nitrogen (NOx) from a gas turbine combustor. Combustor inlet air temperature ranged from 506 K (450 F) to 838 K (1050 F). The tests were primarily run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NOx emission index was found to decrease with increasing inlet air humidity at a constant exponential rate: NOx = NOx0e-19H (where H is the humidity and the subscript 0 denotes the value at zero humidity). the emission index increased exponentially with increasing normalized inlet air temperature to the 1.14 power. Additional tests made to determine the effect of pressure and reference Mach number on NOx showed that the NOx emission index varies directly with pressure to the 0.5 power and inversely with reference Mach number.

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

78

Physical properties of heavy liquid-metal coolants in a wide temperature range  

NASA Astrophysics Data System (ADS)

The pulse-phase method, the gamma-attenuation method and the method of dumping oscillation of a crucible with a melt were used for measuring the velocity of sound, the density and the kinematic viscosity of a set of liquid-metal coolants for perspective nuclear reactors. There are liquid gallium, indium, tin, lead, bismuth and lead-bismuth eutectic alloy among the melts investigated. The accuracy of the measurements was as high as 0.3%, 0.2 to 0.4% and 1.5% for the ultrasound velocity, the density and the viscosity, correspondingly.

Popel, P.; Stankus, S.; Mozgovoy, A.; Khairulin, R.; Pokrasin, M.; Yagodin, D.; Konstantinova, N.; Borisenko, A.; Guzachev, M.

2011-05-01

79

Unsteady Euler analysis of the redistribution of an inlet temperature distortion in a turbine  

Microsoft Academic Search

Temperature migration behavior in rotor flow fields was analyzed using a three-dimensional unsteady Euler code in the effort to explain why rotor airfoil surfaces and passage endwalls experience higher than expected temperatures in engine environments. The time-averaged unsteady solution shows the hotter gas tending to migrate toward the rotor pressure side and the colder gas toward the suction side. Secondary

R. K. Takahashi; R. H. Ni

1990-01-01

80

Sizing of focused solar collector fields with specified collector tube inlet temperature  

Microsoft Academic Search

An axial temperature differential analysis was used to size the collector field required to power a demonstration project in which 40 kW (electrical) output is required. The number of collectors required to furnish the desired energy and temperature rise in the collector fluid is determined by the requirements of several typical organic working fluid Rankine-cycle energy conversion systems. Calculations based

D. O. Lee; W. P. Schimmel Jr.; J. P. Abbin Jr.

1974-01-01

81

Muir Inlet  

USGS Multimedia Gallery

This ship-deck-based photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, is taken towards the north-northwest and shows the nearly 50-m-high retreating tidewater terminus of the glacier with part of its face capped by a few angular sé...

82

Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size  

Microsoft Academic Search

Radiofrequency (RF) ablation is a minimally invasive method for treatment of primary and metastatic liver tumors. One of the currently commercially available devices employs an internally cooled 17-gauge needle probe. Within the probe, cool water is circulated during ablation, which cools tissue close to the probe resulting in larger lesions. We evaluated the effect of different cooling water temperatures on

Dieter Haemmerich; Louay Chachati; Andrew S. Wright; David M. Mahvi; J. G. Webster

2003-01-01

83

Effect of moderate inlet temperatures in ultra-high-pressure homogenization treatments on physicochemical and sensory characteristics of milk.  

PubMed

The effect of ultra-high-pressure homogenization (UHPH) on raw whole milk (3.5% fat) was evaluated to obtain processing conditions for the sterilization of milk. Ultra-high-pressure homogenization treatments of 200 and 300 MPa at inlet temperatures (Ti) of 55, 65, 75, and 85 °C were compared with a UHT treatment (138 °C for 4s) in terms of microbial inactivation, particle size and microstructure, viscosity, color, buffering capacity, ethanol stability, propensity to proteolysis, and sensory evaluation. The UHPH-treated milks presented a high level of microbial reduction, under the detection limit, for treatments at 300 MPa with Ti of 55, 65, 75, and 85 °C, and at 200 MPa with Ti = 85 °C, and few survivors in milks treated at 200 MPa with Ti of 55, 65, and 75 °C. Furthermore, UHPH treatments performed at 300 MPa with Ti = 75 and 85 °C produced sterile milk after sample incubation (30 and 45 °C), obtaining similar or better characteristics than UHT milk in color, particle size, viscosity, buffer capacity, ethanol stability, propensity to protein hydrolysis, and lower scores in sensory evaluation for cooked flavor. PMID:24342690

Amador-Espejo, G G; Suŕrez-Berencia, A; Juan, B; Bárcenas, M E; Trujillo, A J

2014-02-01

84

Investigation of the Influence of Cooling Water Inlet Temperature on Characteristics and Ammonia Charging Quantity of Ammonia-Water Absorption Refrigerator  

NASA Astrophysics Data System (ADS)

For purposes such as freezing and ice accumulation which require temperatures below 0 degrees, ammonia-water absorption refrigerator is being looked at once again. If used for these purpose, it is usually driven all through the year. In this case, cooling water inlet temperature which greatly influences absorption cycle changes very widely. So in such conditions, it is hoped to be driven high efficiently. And ammonia's charging quantity is required as small as possible on account of poisonous. But when it driven all through the year, ammonia charging quantity influences the efficiency greatly. So this research aims to clarify the ammonia charging quantity with which ammonia-water absorption refrigerator can be driven high efficiently. So static simulation model was made. By using this tool, we investigated the influence of cooling water inlet temperature on COP, solution concentration. As a result, minimum ammonia charging quantity with which ammonia water absorption refrigerator can be driven was obtained.

Takei, Toshitaka; Saito, Kiyoshi; Kawai, Sunao

85

Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels  

NASA Technical Reports Server (NTRS)

The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.

Tower, Leonard K; Gammon, Benson E

1953-01-01

86

Thermal stratification potential in rocket engine coolant channels  

NASA Technical Reports Server (NTRS)

The potential for rocket engine coolant channel flow stratification was computationally studied. A conjugate, 3-D, conduction/advection analysis code (SINDA/FLUINT) was used. Core fluid temperatures were predicted to vary by over 360 K across the coolant channel, at the throat section, indicating that the conventional assumption of a fully mixed fluid may be extremely inaccurate. Because of the thermal stratification of the fluid, the walls exposed to the rocket engine exhaust gases will be hotter than an assumption of full mixing would imply. In this analysis, wall temperatures were 160 K hotter in the turbulent mixing case than in the full mixing case. The discrepancy between the full mixing and turbulent mixing analyses increased with increasing heat transfer. Both analysis methods predicted identical channel resistances at the coolant inlet, but in the stratified analysis the thermal resistance was negligible. The implications are significant. Neglect of thermal stratification could lead to underpredictions in nozzle wall temperatures. Even worse, testing at subscale conditions may be inadequate for modeling conditions that would exist in a full scale engine.

Kacynski, Kenneth J.

1992-01-01

87

Turbomachine injection nozzle including a coolant delivery system  

SciTech Connect

An injection nozzle for a turbomachine includes a main body having a first end portion that extends to a second end portion defining an exterior wall having an outer surface. A plurality of fluid delivery tubes extend through the main body. Each of the plurality of fluid delivery tubes includes a first fluid inlet for receiving a first fluid, a second fluid inlet for receiving a second fluid and an outlet. The injection nozzle further includes a coolant delivery system arranged within the main body. The coolant delivery system guides a coolant along at least one of a portion of the exterior wall and around the plurality of fluid delivery tubes.

Zuo, Baifang (Simpsonville, SC)

2012-02-14

88

Inlet Performance Analysis Code Developed  

NASA Technical Reports Server (NTRS)

The design characteristics of an inlet very much depend on whether the inlet is to be flown at subsonic, supersonic, or hypersonic speed. Whichever the case, the primary function of an inlet is to deliver free-stream air to the engine face at the highest stagnation pressure possible and with the lowest possible variation in both stagnation pressure and temperature. At high speeds, this is achieved by a system of oblique and/or normal shock waves, and possibly some isentropic compression. For both subsonic and supersonic flight, current design practice indicates that the inlet should deliver the air to the engine face at approximately Mach 0.45. As a result, even for flight in the high subsonic regime, the inlet must retard (or diffuse) the air substantially. Second, the design of an inlet is influenced largely by the compromise between high performance and low weight. This compromise involves tradeoffs between the mission requirements, flight trajectory, airframe aerodynamics, engine performance, and weight-all of which, in turn, influence each other. Therefore, to study the effects of some of these influential factors, the Propulsion System Analysis Office of the NASA Lewis Research Center developed the Inlet Performance Analysis Code (IPAC). This code uses oblique shock and Prandtl-Meyer expansion theory to predict inlet performance. It can be used to predict performance for a given inlet geometric design such as pitot, axisymmetric, and two-dimensional. IPAC also can be used to design preliminary inlet systems and to make subsequent performance analyses. It computes the total pressure, the recovery, the airflow, and the drag coefficients. The pressure recovery includes losses associated with normal and oblique shocks, internal and external friction, the sharp lip, and diffuser components. Flow rate includes captured, engine, spillage, bleed, and bypass flows. The aerodynamic drag calculation includes drags associated with spillage, cowl lip suction, wave, bleed, and bypass.

Jules, Kenol; Barnhart, Paul J.

1998-01-01

89

Coolant line hydrometer  

Microsoft Academic Search

This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein

M. D. Barber; W. G. Kipp

1987-01-01

90

Influence of HTR core inlet and outlet temperatures on hydrogen generation efficiency using the sulfur-iodine water-splitting cycle  

SciTech Connect

The performance of hydrogen production via thermochemical cycles is typically evaluated using thermal efficiency. In this study, the sulfur-iodine cycle with heat supplied by a high-temperature reactor (HTR) is analyzed. Two cases are examined: one flow sheet designed by General Atomics in the United States, the other by Commissariat a l'energie atomique et aux energies alternatives in France. In each case, HTR helium inlet and outlet temperatures are specified. Differences in these temperature specifications lead to process variations between the limy sheets and in how the hydrogen processes interface with the nuclear heat source. Two principal conclusions result from the analysis. First, the thermal efficiency tends to plateau above a certain outlet helium temperature. This is a characteristic effect of the method of Ozturk et al. for sulfuric acid decomposition. Second, it is clear that it is impractical to discuss efficiencies for the hydrogen process that are independent of defined operating parameters of the HTR. (authors)

Buckingham, Robert; Brown, Lloyd; Russ, Ben [Gen Atom Co, San Diego, CA 92121 (United States); Lovera, Patrick; Carles, Philippe; Borgard, Jean-Marc; Yvon, Pascal [CEA, DEN, F-91191 Gif Sur Yvette, (France)

2012-04-15

91

Coolant line hydrometer  

SciTech Connect

This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein individually as a function of the specific gravity of the coolant. The coolant receiving chamber means includes a closure cap which when connected to the tubular fitting forms a coolant receiving chamber, retaining means for retaining the indicating float elements within the coolant receiving chamber, a viewing window member of a substantially clear material through which the float elements can be visually observed within the coolant receiving chamber means, and air venturi means located within the coolant receiving chamber means for automatically removing air which may collect within the coolant chamber means.

Barber, M.D.; Kipp, W.G.

1987-03-17

92

Optimizations of packed sorbent and inlet temperature for large volume-direct aqueous injection-gas chromatography to determine high boiling volatile organic compounds in water.  

PubMed

For the expanded application area, fast trace analysis of certain high boiling point (i.e., 150-250 °C) volatile organic compounds (HVOCs) in water, a large volume-direct aqueous injection-gas chromatography (LV-DAI-GC) method was optimized for the following parameters: packed sorbent for sample on-line pretreatment, inlet temperature and detectors configuration. Using the composite packed sorbent self-prepared with lithium chloride and a type of diatomite, the method enabled safe injection of an approximately 50-100 ?L sample at an inlet temperature of 150 °C in the splitless mode and separated HVOCs from water matrix in 2 min. Coupled with a flame ionization detector (FID), an electron capture detector (ECD) and a flame photometric detector (FPD), the method could simultaneously quantify 27 HVOCs that belong to seven subclasses (i.e., halogenated aliphatic hydrocarbons, chlorobenzenes, nitrobenzenes, anilines, phenols, polycyclic aromatic hydrocarbons and organic sulfides) in 26 min. Injecting a 50 ?L sample without any enrichment step, such as cryotrap focusing, the limits of quantification (LOQs) for the 27 HVOCs was 0.01-3 ?g/L. Replicate analyses of the 27 HVOCs spiked source and river water samples exhibited good precision (relative standard deviations ? 11.3%) and accuracy (relative errors ? 17.6%). The optimized LV-DAI-GC was robust and applicable for fast determination and automated continuous monitoring of HVOCs in surface water. PMID:24997514

Yu, Bofan; Song, Yonghui; Han, Lu; Yu, Huibin; Liu, Yang; Liu, Hongliang

2014-08-22

93

Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core  

SciTech Connect

The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M. [Korea Atomic Energy Research Inst., Daedeok-daero 989-11, Yuseong-gu, Daejeon (Korea, Republic of)

2012-07-01

94

Measuring flow and pressure of lithium coolant under developmental testing of a high-temperature cooling system of a space nuclear power plant  

NASA Astrophysics Data System (ADS)

Sub-megawatt space NPP use lithium as a coolant and niobium alloy as a structural material. In order to refine the lithium-niobium technology of the material and design engineering, lithium-niobium loops were worked out in RSC Energia, and they were tested at a working temperature of lithium equal to 1070-1300 K. In order to measure the lithium flow and pressure, special gauges were developed, which made possible the calibration and checkout of the loops without their dismantling. The paper describes the architecture of the electromagnetic flowmeter and the electromagnetic vibrating-wire pressure transducer (gauge) for lithium coolant in the nuclear power plant cooling systems. The operating principles of these meters are presented. Flowmeters have been developed for channel diameters ranging from 10 to 100 mm, which are capable of measuring lithium flows in the range of 0.1 to 30 L/s with the error of 3% for design calibration and 1% for volume graduation. The temperature error of the pressure transducers does not exceed 0.4% per 100 K; the nonlinearity and hysteresis of the calibration curve do not exceed 0.3 and 0.4%, respectively. The transducer applications are illustrated by the examples of results obtained from tests on the NPP module mockup and heat pipes of a radiation cooler.

Sobolev, V. Ya.; Sinyavsky, V. V.

2014-12-01

95

Preliminary Study on Utilization of Carbon Dioxide as a Coolant of High Temperature Engineering Test Reactor with MOX and Minor Actinides Fuel  

NASA Astrophysics Data System (ADS)

High temperature engineering test reactor (HTTR) is an uranium oxide (UO2) fuel, graphite moderator and helium gas-cooled reactor with 30 MW in thermal output and outlet coolant temperature of 950° C. Instead of using helium gas, we have utilized carbon dioxide as a coolant in the present study. Beside that, uranium and plutonium oxide (mixed oxide, MOX) and minor actinides have been employed as a new fuel type of HTTR. Utilization of plutonium and minor actinide is one of the support system to non-proliferation issue in the nuclear development. The enrichment for uranium oxide has been varied of 6-20% with plutonium and minor actinides concentration of 10%. In this study, burnup period is 1100 days. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. Reactor core calculation was done by using CITATION module. The result shows that HTTR can achieve its criticality condition with 14% of 235U enrichment.

Fauzia, A. F.; Waris, A.; Novitrian

2010-06-01

96

Steady-state inlet temperature distortion effects on the stall limits of a J85-Ge-13 turbojet engine  

NASA Technical Reports Server (NTRS)

The effects of circumferential and radial temperature distortions and combined temperature and pressure distortion on the performance of a J85-GE-13 turbojet engine were investigated. In terms of loss of compressor pressure ratio at stall, the most severe pattern of temperature distortion was hub radial while a circumferential pattern of diametrically opposed sectors was least severe. The effect of combined temperature and pressure distortion was dependent on the location of the high temperature and low pressure regions. The most serious stall pressure ratio losses occurred when these regions coincided.

Mehalic, C. M.; Lottig, R. A.

1974-01-01

97

Afterburner Performance of Circular V-Gutters and a Sector of Parallel V-Gutters for a Range of Inlet Temperatures to 1255 K (1800 F)  

NASA Technical Reports Server (NTRS)

Combustion tests of two V-gutter types were conducted in a 19.25-in. diameter duct using vitiated air. Fuel spraybars were mounted in line with the V-gutters. Combustor length was set by flame-quench water sprays which were part of a calorimeter for measuring combustion efficiency. Although the levels of performance of the parallel and circular array afterburners were different, the trends with geometry variations were consistent. Therefore, parallel arrays can be used for evaluating V-gutter geometry effects on combustion performance. For both arrays, the highest inlet temperature produced combustion efficiencies near 100 percent. A 5-in. spraybar - to - V-gutter spacing gave higher efficiency and better lean blowout performance than a spacing twice as large. Gutter durability was good.

Brandstetter, J. Robert; Reck, Gregory M.

1973-01-01

98

Development of a high-sensitivity quantitative analytical method for determining polycarbamate by gas chromatography-mass spectrometry incorporating temperature-programmable inlet on-column injection.  

PubMed

A highly sensitive analytical method was developed using GC/MS with temperature-programmable inlet on-column injection (TPI on-column GC/MS) for determining methyl dimethyldithiocarbamate (DMDC-methyl) and dimethyl ethylenebisdithiocarbamate (EBDC-dimethyl), which are methyl derivatives of alkali decomposed polycarbamate. This method makes it possible to quantify 0.3 microg/l of polycarbamate in tap water, which is a 1/100 of the residual target value of 30 microg/l in Japan. Moreover, it now becomes possible to distinguish polycarbamate from other dithiocarbamate pesticides (DTCs) that have similar structures, including ziram and thiram, which only incorporate a DMDC side chain, or manzeb, maneb and zineb, which only incorporate an EBDC side chain, by simultaneously analyzing for DMDC-methyl and EBDC-dimethyl. PMID:15941051

Kawamoto, Tatsuhiko; Yano, Miho; Makihata, Nobuko

2005-05-13

99

Development of Wing Inlets  

NASA Technical Reports Server (NTRS)

Lift, drag, internal flow, and pressure distribution measurements were made on a low-drag airfoil incorporating various air inlet designs. Two leading-edge air inlets are developed which feature higher lift coefficients and critical Mach than the basic airfoil. Higher lift coefficients and critical speeds are obtained for leading half of these inlet sections but because of high suction pressures near exist, slightly lower critical speeds are obtained for the entire inlet section than the basic airfoil.

Racisz, Stanley F.

1946-01-01

100

Directly connected heat exchanger tube section and coolant-cooled structure  

DOEpatents

A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

2014-04-01

101

Experimental Investigation and Analysis of an Axial Compressor Stage with 45° Circumferential Inlet Flow Pressure Distortion  

Microsoft Academic Search

When designing compressors, inlet flow is always assumed to be uniform and axisymmetric. In fact, inlet flow is non-uniform and can cause quite a different result. The inlet flow distortion is caused by many reasons, such as aircraft attitude changes and inlet airframe effects. Usually, distortion is characterized by nonuniformity in the inlet flow parameters of velocity, pressure, temperature, flow

J. Huang; H. Wu; W. H. Du

2009-01-01

102

Experimental Surveys for Submerged Inlet  

NASA Astrophysics Data System (ADS)

The objective of the study is to define the Pareto set of designs for a subsonic submerged inlet that minimizes flow distortion and swirl at the engine face. A series of experimental surveys are performed to validate the accompanying computations and to provide additional information regarding the Pareto set. A stainless steel model with a removable submerged inlet (built using an FDM system) has been fabricated and installed in the Rutgers University subsonic wind tunnel. Boundary layer measurements upstream of the inlet are obtained by a computer-controlled traversing pitot tube. The estimated boundary layer thickness agrees closely with the computed profile. Detailed experiments are focused on the measurement of total pressure three diameters downstream of the exit of the inlet. A rotating multi-element pitot rack is fabricated and installed in the model, which is attached to the suction side of a blower to yield the appropriate mass flow rate through the inlet. Motion control, pressure and temperature data acquisition as well as management of the wind tunnel operations for all experiments are controlled by a LabView program developed at Rutgers University.

Jovanovic, Vasilije; Taskinoglu, Ezgi; Elliott, Gregory; Knight, Doyle

2003-11-01

103

Preliminary studies of coolant by-pass flows in a prismatic very high temperature reactor using computational fluid dynamics  

SciTech Connect

Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor core.

Hiroyuki Sato; Richard Johnson; Richard Schultz

2009-09-01

104

Machine coolant recycling system  

SciTech Connect

Machining processes at the 272W Site Fabrication Services (SFS) produce a waste stream consisting of dirty machine coolant. During use the coolant becomes contaminated with metal chips from milling, and oil, dirt and solvents from the machining process. The mixture is designated as a Washington State dangerous waste with WP02 (persistence), D007 (chromium) and D008 (lead) waste codes. This process results in the generation of 13.5 m{sup 3} of hazardous waste per year with an annual cost for coolant replacement, waste management and waste disposal of approximately $137,000. To identify alternatives to this situation, ICF Kaiser Hanford Company (ICF KH) North Environmental Services conducted a pollution prevention opportunity assessment (P20A) on the machining processes. A coolant recycler and sump sucker unit were selected as the most cost-effective waste reduction options. In December 1994, ICF KH received return on investment (ROI) funding from the U.S. Department of Energy Richland Operations Office (DOE-RL) to implement this option. The coolant recycling and the sump sucker units were purchased and installed in July 1995 at a total cost of $61,000. The sump sucker removes the dirty coolant from the fabrication machinery and filters it to remove shavings and sludge. The filtered coolant then is transferred to the coolant recycling system for further processing. The coolant recycling system reconditions the filtered coolant for use in the machining equipment, and mixes the concentrated coolant to the correct concentration. As a result of implementing this option, the annual generation of waste coolant was reduced by 12 m{sup 3}. The annual cost savings exceed $119,000 with an ROI of 186%. Additional benefits include reduced coolant usage; improved tool life, wheel life, finish, size control, corrosion protection, and operator working conditions; increase machine {open_quotes}up-time{close_quotes}; and reduced machine tool maintenance.

Grabner, T.A. [ICF Kaiser Hanford Company, Richland, WA (United States)

1996-12-31

105

Autoignition in a premixing-prevaporizing fuel duct using 3 different fuel injection systems at inlet air temperatures to 1250 K  

NASA Technical Reports Server (NTRS)

Conditions were determined in a continuous-flow, premixing-prevaporizing duct at which autoignition occurred. Test conditions were representative of an advanced, regenerative-cycle, automotive gas turbine. The test conditions inlet air temperatures from 600 to 1250 K (a vitiated preheater was used), pressures from 170 to 600 kPa, air velocities of 10 to 30 m/sec, equivalence ratios from 0.3 to 1.0, mixing lengths from 10 to 60 cm, and residence times of 2 to 100 ms. The fuel was diesel number 2. The duct was insulated and had an inside diameter of 12 cm. Three different fuel injection systems were used: One was a single simplex pressure atomizer, and the other two were multiple-source injectors. The data obtained with the simplex and one of the multiple-source injectors agreed satisfactorily with the references and correlated with an Arrenhius expression. The data obtained with the other multiple source injector, which used multiple cones to improve the fuel-air distribution, did not correlate well with residence time.

Tacina, R. R.

1983-01-01

106

Flow through aligned sequential orifice type inlets  

NASA Technical Reports Server (NTRS)

Chocked flow rate and pressure profile data were taken and studied for configurations consisting of four axially aligned, sequential orifice inlets of 0.5 length diameter ratio with separation distances of 0.66 and 32 diameters. A flow coefficient - reduced temperature plot represents the flow rate data for the two cases. At a separation distance of 32 diameters the pressure profiles dropped sharply at the entrance and partially recovered within each orifice - the exception being at low temperatures, where fluid jetting through the last orifice occurred. At a separation distance of 0.66 diameter fluid jetting was prevalent at the lower inlet temperatures. These results are in qualitative agreement with data for four axially aligned, sequential Borda inlets and for tubes with single sharp edge orifice or Borda inlets to L/D's of 105 and with a water flow visualization study.

Hendricks, R. C.; Stetz, T. T.

1982-01-01

107

Attic Inlet Technology Update  

Technology Transfer Automated Retrieval System (TEKTRAN)

Attic inlets are a popular addition for new construction and energy saving retrofits. Proper management of attic inlets is necessary to get maximum benefits from the system and reduce the likelihood of moisture-related problems in the structure. Solar energy levels were determined for the continen...

108

The induction of water to the inlet air as a means of internal cooling in aircraft-engine cylinders  

NASA Technical Reports Server (NTRS)

Report presents the results of investigations conducted on a full-scale air-cooled aircraft-engine cylinder of 202-cubic inch displacement to determine the effects of internal cooling by water induction on the maximum permissible power and output of an internal-combustion engine. For a range of fuel-air and water-fuel ratios, the engine inlet pressure was increased until knock was detected aurally, the power was then decreased 7 percent holding the ratios constant. The data indicated that water was a very effective internal coolant, permitting large increases in engine power as limited by either knock or by cylinder temperatures.

Rothrock, Addison M; Krsek, Alois, Jr; Jones, Anthony W

1943-01-01

109

Machine coolant waste reduction by optimizing coolant life. Project summary  

SciTech Connect

The project was designed to study the following: A specific water-soluble coolant (Blasocut 2000 Universal) in use with a variety of machines, tools, and materials; Coolant maintenance practices associated with three types of machines; Health effects of use and handling of recycled coolant; Handling practices for chips and waste coolant; Chip/coolant separation; and Oil/water separation.

Pallansch, J.

1995-08-01

110

Assessment of the Use of Nitrogen Trifluoride for Purifying Coolant and Heat Transfer Salts in the Fluoride Salt-Cooled High-Temperature Reactor  

SciTech Connect

This report provides an assessment of the use of nitrogen trifluoride for removing oxide and water-caused contaminants in the fluoride salts that will be used as coolants in a molten salt cooled reactor.

Scheele, Randall D.; Casella, Andrew M.

2010-09-28

111

Automobile coolant flow control  

Microsoft Academic Search

A two-stage flow controller is described for use in a vehicle heating circuit, comprising: a housing having an inlet and an outlet and a flow control chamber intermediate the inlet and outlet; structure defining a valve seat within the chamber; a flow controller assembly slidably disposed in the chamber for movement towards and away from the seat; biasing means urging

Yeoman

1989-01-01

112

On-site profiling and speciation of polycyclic aromatic hydrocarbons at manufactured gas plant sites by a high temperature transfer line, membrane inlet probe coupled to a photoionization detector and gas chromatography\\/mass spectrometer  

Microsoft Academic Search

A new high temperature transfer line, membrane inlet probe (HTTL-MIP) coupled to a photoionization detector (PID) and gas chromatograph\\/mass spectrometer (GC\\/MS) was used to rapidly profile and speciate polycyclic aromatic hydrocarbons (PAH) in the subsurface. PID signals were in agreement with GC\\/MS results. Correlation coefficients of 0.92 and 0.99 were obtained for discrete and composite samples collected from the same

Thomas Considine; Albert Robbat Jr

2008-01-01

113

DESIGN OF SUPERSONIC INLETS  

NASA Technical Reports Server (NTRS)

This FORTRAN IV computer program which incorporates the method of characteristics was written to assist in the design of supersonic inlets. There were two objectives: (1) to study a greater variety of supersonic inlet configurations and (2) to reduce the time required for trial-and-error procedures to arrive at optimum inlet design. The computer program was written with the intention of being able to construct a variety of inlet configurations by interchanging specific subroutines. In this manner, greater flexibility of choice was attained, and the time required to program a specific inlet configuration was greatly reduced. The second objective was accomplished by a reformulation of the boundary value problem for hyperbolic equations. By this reformulation of the boundary data, the engineering design quantities, throat Mach number and flow angle, were introduced as direct input quantities to the computer program. As a consequence of introducing the engineering parameters as input, the computer program will calculate the surface contours required to satisfy the specific throat conditions. Inviscid flow is assumed and the method used to calculate the inlet contour results in minimum distortion to the flow in the throat. This program was developed on an IBM 7094.

Anderson, B. H.

1994-01-01

114

Lead Coolant Test Facility Technical and Functional Requirements, Conceptual Design, Cost and Construction Schedule  

SciTech Connect

This report presents preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic. Based on review of current world lead or lead-bismuth test facilities and research need listed in the Generation IV Roadmap, five broad areas of requirements of basis are identified: Develop and Demonstrate Prototype Lead/Lead-Bismuth Liquid Metal Flow Loop Develop and Demonstrate Feasibility of Submerged Heat Exchanger Develop and Demonstrate Open-lattice Flow in Electrically Heated Core Develop and Demonstrate Chemistry Control Demonstrate Safe Operation and Provision for Future Testing. These five broad areas are divided into twenty-one (21) specific requirements ranging from coolant temperature to design lifetime. An overview of project engineering requirements, design requirements, QA and environmental requirements are also presented. The purpose of this T&FRs is to focus the lead fast reactor community domestically on the requirements for the next unique state of the art test facility. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 420oC. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M. It is also estimated that the facility will require two years to be constructed and ready for operation.

Soli T. Khericha

2006-09-01

115

Surface cooling of scramjet engine inlets using heat pipe, transpiration, and film cooling  

SciTech Connect

This article reports the results of applying a finite-difference-based computational technique to the problem of predicting the transient thermal behavior of a scramjet engine inlet exposed to a typical hypersonic flight aerodynamic surface heating environment, including type IV shock interference heating. The leading-edge cooling model utilized incorporates liquid metal heat pipe cooling with surface transpiration and film cooling. Results include transient structural temperature distributions, aerodynamic heat inputs, and surface coolant distributions. It seems that these cooling techniques may be used to hold maximum skin temperatures to near acceptable values during the severe aerodynamic and type IV shock interference heating effects expected on the leading edge of a hypersonic aerospace vehicle scramjet engine. 15 refs.

Modlin, J.M.; Colwell, G.T. (U.S. Army, Strategic Defense Command, Huntsville, AL (United States) Georgia Institute of Technology, Atlanta (United States))

1992-09-01

116

MACHINE COOLANT WASTE REDUCTION BY OPTIMIZING COOLANT LIFE  

EPA Science Inventory

Machine shops use coolants to improve the life and function of machine tools. hese coolants become contaminated with oils with use, and this contamination can lead to growth of anaerobic bacteria and shortened coolant life. his project investigated methods to extend coolant life ...

117

Water inlet blowdown  

NASA Astrophysics Data System (ADS)

A new blowdown system was developed for cleaning debris from the inlet grill of waterjet propulsion system on Boeing hydrofoil boats. A system was required to work with existing waterjet ducts which are open ended. The new blowdown system consists of an abrupt discharge of high pressure compressed air amidst the water inlet duct. It utilizes the open end of the propulsor discharge nozzle as a safety valve. Feasibility was proven by semi-steady state equations and was confirmed by full scale testing. A system was developed and installed and is now fully operational.

Timar, T.

1981-09-01

118

HSCT inlet development issues  

NASA Technical Reports Server (NTRS)

The purpose of this presentation is to highlight the issues affecting the development of engine air inlets for the HSCT. The Propulsion Airframe Integration Technology (PAIT) contract sponsored by NASA LeRC is an important element in the evolution of the propulsion system that will eventually power the HSCT. Most of the material presented here is based on work performed by The Boeing Company under Task 1 and 2 of PAIT. From the propulsion perspective, the premier technology issues associated with the HSCT are airport noise and high altitude emissions. The sources are the nozzle and combustor, respectively. For the inlet the most challenging issues are associated with integration. Among the issues are the following: integration with the main landing gear--protection from FOD and water and slush ingestion from the runway; integration with the engine--ensuring engine/inlet airflow matching, normal shock stability during engine airflow transients, and keeping total pressure distortion within acceptable limits; integration with the wing--minimizing nacelle/wing interference drag and inlet flowfield velocity distortion.

Koncsek, Joseph L.

1992-01-01

119

Interactions between an organic coolant and drops of molten lithium  

Microsoft Academic Search

Twenty scoping experiments were performed to investigate the behavior of nominally 0.5 g molten lithium drops when released into 0.7 L of the organic coolant Therminol 66 at local atmospheric pressure using a vortex insertion technique. Diagnostics consisted of video and photographic imaging and several chemical analyses. Six coolant\\/Li temperature pairs were used: 300\\/300; 300\\/530; 300\\/770; 464\\/530; 600\\/530 and 600\\/770,

L. S. Nelson; J. D. Krueger; M. L. Corradini

1994-01-01

120

Radiant energy receiver having improved coolant flow control means  

DOEpatents

An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

Hinterberger, H.

1980-10-29

121

Safety and environmental aspects of organic coolants for fusion facilities  

NASA Astrophysics Data System (ADS)

Organic coolants, such as OS-84, offer unique advantages for fusion reactor applications. These advantages are with respect to both reactor operation and safety. The key operational advantage is a coolant that can provide high temperature (350-400°C) at modest pressure (2-4 MPa). These temperatures are needed for conditioning the plasma-facing components and, in reactors, for achieving high thermodynamic conversion efficiencies (>40%). The key safety advantage of organic coolants is the low vapor pressure, which significantly reduces the containment pressurization transient (relative to water) following a loss of coolant event. Also, from an occupational dose viewpoint, organic coolants significantly reduce corrosion and erosion inside the cooling system and consequently reduce the quantity of activation products deposited in cooling system equipment. On the negative side, organic coolants undergo both pyrolytic and radiolytic decomposition, and are flammable. While the decomposition rate can be minimized by coolant system design (by reducing coolant inventories exposed to neutron flux and to high temperatures), decomposition products are formed and these degrade the coolant properties. Both heavy compounds and light gases are produced from the decomposition process, and both must be removed to maintain adequate coolant properties. As these hydrocarbons may become tritiated by permeation, or activated through impurities, their disposal could create an environmental concern. Because of this potential waste disposal problem, consideration has been given to the recycling of both the light and heavy products, thereby reducing the quantity of waste to be disposed. Preliminary assessments made for various fusion reactor designs, including ITER, suggest that it is feasible to use organic coolants for several applications. These applications range from first wall and blanket coolant (the most demanding with respect to decomposition), to shield and vacuum vessel cooling, to an intermediate cooling loop removing heat from a liquid metal loop and transferring it to a steam generator or heat exchanger.

Natalizio, A.; Hollies, R. E.; Gierszewski, P.

1993-06-01

122

Environmentally Friendly Coolant System  

SciTech Connect

Energy reduction through the use of the EFCS is most improved by increasing machining productivity. Throughout testing, nearly all machining operations demonstrated less land wear on the tooling when using the EFCS which results in increased tool life. These increases in tool life advance into increased productivity. Increasing productivity reduces cycle times and therefore reduces energy consumption. The average energy savings by using the EFCS in these machining operations with these materials is 9%. The advantage for end milling stays with flood coolant by about 6.6% due to its use of a low pressure pump. Face milling and drilling are both about 17.5% less energy consumption with the EFCS than flood coolant. One additional result of using the EFCS is improved surface finish. Certain machining operations using the EFCS result in a smoother surface finish. Applications where finishing operations are required will be able to take advantage of the improved finish by reducing the time or possibly eliminating completely one or more finishing steps and thereby reduce their energy consumption. Some machining operations on specific materials do not show advantages for the EFCS when compared to flood coolants. More information about these processes will be presented later in the report. A key point to remember though, is that even with equivalent results, the EFCS is replacing petroleum based coolants whose production produces GHG emissions and create unsafe work environments.

David Jackson Principal Investigator

2011-11-08

123

A Heated Tube Facility for Rocket Coolant Channel Research  

NASA Technical Reports Server (NTRS)

The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented. The facility uses high current, low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C (1350 F). Liquid or gaseous nitrogen, gaseous helium, or combustible liquids can be used as the test section coolant. The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system. Test section geometry, size, and material; coolant properties; and heating levels can be varied to generate heat transfer and coolant performance data bases.

Green, James M.; Pease, Gary M.; Meyer, Michael L.

1995-01-01

124

Automatic coolant flow control device for a nuclear reactor assembly  

DOEpatents

A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

Hutter, Ernest (Wilmette, IL)

1986-01-01

125

Automatic coolant flow control device for a nuclear reactor assembly  

DOEpatents

A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

Hutter, E.

1984-01-27

126

Fuel cell system with coolant flow reversal  

DOEpatents

Method and apparatus for cooling electrochemical fuel cell system components. Periodic reversal of the direction of flow of cooling fluid through a fuel cell stack provides greater uniformity and cell operational temperatures. Flow direction through a recirculating coolant fluid circuit is reversed through a two position valve, without requiring modulation of the pumping component.

Kothmann, Richard E. (Pittsburgh, PA)

1986-01-01

127

Analysis of Scramjet Inlets  

NASA Technical Reports Server (NTRS)

NASCRIN program analyzes two-dimensional flow fields in supersoniccombustion ramjet (scramjet) inlets. Solves two-dimensional Euler or Navier-Stokes equations in conservative form by unsplit, explicit, two-step finite-difference method. More recent explicit/implicit, two-step scheme incorporated by analysis of viscous flow. Algebraic, two-layer eddy-viscosity model used for turbulent-flow calculations. Vectorized version, written for CDC CYBER 205, whereas scalar version, can be run on CRAY or other scalar computers.

Kumar, A.

1987-01-01

128

CFD analyses of coolant channel flowfields  

NASA Technical Reports Server (NTRS)

The flowfield characteristics in rocket engine coolant channels are analyzed by means of a numerical model. The channels are characterized by large length to diameter ratios, high Reynolds numbers, and asymmetrical heating. At representative flow conditions, the channel length is approximately twice the hydraulic entrance length so that fully developed conditions would be reached for a constant property fluid. For the supercritical hydrogen that is used as the coolant, the strong property variations create significant secondary flows in the cross-plane which have a major influence on the flow and the resulting heat transfer. Comparison of constant and variable property solutions show substantial differences. In addition, the property variations prevent fully developed flow. The density variation accelerates the fluid in the channels increasing the pressure drop without an accompanying increase in heat flux. Analyses of the inlet configuration suggest that side entry from a manifold can affect the development of the velocity profile because of vortices generated as the flow enters the channel. Current work is focused on studying the effects of channel bifurcation on the flow field and the heat transfer characteristics.

Yagley, Jennifer A.; Feng, Jinzhang; Merkle, Charles L.

1993-01-01

129

Numerical Simulation For Supersonic Inlets  

NASA Technical Reports Server (NTRS)

Flows calculated for realistic engine-inlet conditions. Computer code LAPIN, large-perturbation inlet, developed to analyze large-perturbation, transient-flow fields in supersonic inlets. Robust, quick-running code capable of solving unsteady quasi-one-dimensional, inviscid-flow problems in mixed subsonic and supersonic regimes for inlets. Approach based upon quasi-one-dimensional, inviscid, unsteady formulation including engineering models of unstart/restart, bleed, bypass, and geometrical effects. Numerical solution of governing time-dependent equations of motion accomplished through shock-capturing, finite-difference algorithm. Program written in FORTRAN IV.

Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.

1987-01-01

130

Method for removing cesium from a nuclear reactor coolant  

DOEpatents

A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium

Colburn, Richard P. (Pasco, WA)

1986-01-01

131

Reactor coolant pump flywheel  

DOEpatents

A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

2013-11-26

132

Oscillating-Coolant Heat Exchanger  

NASA Technical Reports Server (NTRS)

Devices useful in situations in which heat pipes inadequate. Conceptual oscillating-coolant heat exchanger (OCHEX) transports heat from its hotter portions to cooler portions. Heat transported by oscillation of single-phase fluid, called primary coolant, in coolant passages. No time-averaged flow in tubes, so either heat removed from end reservoirs on every cycle or heat removed indirectly by cooling sides of channels with another coolant. Devices include leading-edge cooling devices in hypersonic aircraft and "frost-free" heat exchangers. Also used in any situation in which heat pipe used and in other situations in which heat pipes not usable.

Scotti, Stephen J.; Blosser, Max L.; Camarda, Charles J.

1992-01-01

133

Experimental Surveys for Submerged Inlet  

Microsoft Academic Search

The objective of the study is to define the Pareto set of designs for a subsonic submerged inlet that minimizes flow distortion and swirl at the engine face. A series of experimental surveys are performed to validate the accompanying computations and to provide additional information regarding the Pareto set. A stainless steel model with a removable submerged inlet (built using

Vasilije Jovanovic; Ezgi Taskinoglu; Gregory Elliott; Doyle Knight

2003-01-01

134

Effects of optimized and sub-optimum two degree of freedom lining tolerances on modeled inlet acoustic attenuation and Normal incidence impedance measurement at elevated temperatures  

NASA Astrophysics Data System (ADS)

This work first investigates the effect of manufacturing tolerances on realized attenuation for two degree-of-freedom linings with the use of lining models and finite element duct propagation codes. Acoustic linings were created for two turbofan engines that optimize attenuation at takeoff/sideline and approach conditions. Lining physical and geometric parameters were set, which best meet the optimum impedance requirements at two target frequencies. Similar linings were created to investigate sub-optimum designs. Variations of these parameters representing realistic manufacturing tolerances were used to systematically examine the effect on installed impedance and predicted attenuation. Attenuation at sideline and approach conditions was found to be sensitive to manufacturing tolerances around optimum conditions. The results of the study are case dependent; however the analysis scheme presented provides a method for cost-benefit analysis of manufacturing processes. In a second study, an impedance tube, with an associated data analysis method, was developed and analyzed for temperature uncertainties that allowed the measurement of impedance of acoustic samples at elevated temperatures. This impedance measurement method was validated at room temperature by comparing the results with predicted impedance from empirically based impedance models and with impedance measurements in a standard traversing microphone impedance tube. Impedance for four samples was measured at elevated temperatures, and the results were compared to room temperature measurements. For two of the samples, the impedances measured at elevated temperatures were compared to the results of extensions of room temperature empirical models, confirming the trend of the results of the elevated temperature measurements.

Burd, David R.

135

Summary of investigations of engine response to distorted inlet conditions  

NASA Technical Reports Server (NTRS)

A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. This includes a description of the hardware and techniques employed, and a summary of the highlights of experimental investigations and analytical modeling. Distortion devices successfully simulated inlet distortion, and knowledge was gained about compression system response to different types of distortion. A list of NASA research references is included.

Biesiadny, T. J.; Braithwaite, W. M.; Soeder, R. H.; Abdelwahab, M.

1986-01-01

136

Summary of investigations of engine response to distorted inlet conditions  

NASA Technical Reports Server (NTRS)

A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. Results of experimental investigations and analytical modeling are reviewed together with a description of the hardware and the techniques employed. Distortion devices successfully simulated inlet distortion, and knowledge was gained on compression system response to different types of distortion. A list of NASA research references is included.

Biesiadny, Thomas J.; Braithwaite, Willis M.; Soeder, Ronald H.; Abdelwahab, Mahmood

1987-01-01

137

Inlet airflow distortion in turbomachinery  

Microsoft Academic Search

Summary The attenuation of an inlet flow distortion in a single stage mixed flow compressor is calculated. Use is made of a modified actuator disc theory. The case where the axial gaps are very small is considered in particular.

Yosimiti Tanida

1972-01-01

138

Coolant passage heat transfer with rotation  

NASA Astrophysics Data System (ADS)

In current and advanced gas turbine engines, increased speeds, pressures and temperatures are used to reduce specific fuel consumption and increase thrust/weight ratios. Hence, the turbine airfoils are subjected to increased heat loads escalating the cooling requirements to satisfy life goals. The efficient use of cooling air requires that the details of local geometry and flow conditions be adequately modeled to predict local heat loads and the corresponding heat transfer coefficients. The objective of this program is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

Hajek, T. J.; Wagner, J.; Johnson, B. V.

1986-10-01

139

Estimation of temperature-induced reactor coolant system and steam generator tube creep rupture probability under high-pressure severe accident conditions  

Microsoft Academic Search

A severe accident has inherently significant uncertainties due to the complex phenomena and wide range of conditions. Because of its high temperature and pressure, performing experimental validation and practical application are extremely difficult. With these difficulties, there has been few experimental researches performed and there is no plant-specific experimental data. Instead, computer codes have been developed to simulate the accident

Youngsuk Bang; Gunhyo Jung; Byungchul Lee; Kwang-Il Ahn

2012-01-01

140

Investigation of "6X" Scramjet Inlet Configurations  

NASA Technical Reports Server (NTRS)

This work represents an initial attempt to determine what, if any, issues arise from scaling demonstration supersonic combustion scramjets to a flight scale making the engine a viable candidate for both military weapon and civilian access to space applications. The original vehicle sizes tested and flown to date, were designed to prove a concept. With the proven designs, use of the technology for applications as weapon systems or space flight are only possible at six to ten times the original scale. To determine effects of scaling, computations were performed with hypersonic inlets designed to operate a nominal Mach 4 and Mach 5 conditions that are possible within the eight foot high temperature tunnel at NASA Langley Research Center. The total pressure recovery for these inlets is about 70%, while maintaining self start conditions, and providing operable inflow to combustors. Based on this study, the primary scaling effect detected is the strength of a vortex created along the cowl edge causing adverse boundary layer growth in the inlet.

Alter, Stephen J.

2012-01-01

141

Experimental Investigation and Analysis of an Axial Compressor Stage with 45° Circumferential Inlet Flow Pressure Distortion  

NASA Astrophysics Data System (ADS)

When designing compressors, inlet flow is always assumed to be uniform and axisymmetric. In fact, inlet flow is non-uniform and can cause quite a different result. The inlet flow distortion is caused by many reasons, such as aircraft attitude changes and inlet airframe effects. Usually, distortion is characterized by nonuniformity in the inlet flow parameters of velocity, pressure, temperature, flow angle, or gas constituency. In this field, inlet flow total pressure distortion is quite an important subject where the attention is concentrated on “steady-state” distortion patterns (magnitude and extent nonfluctuating with time). A lot of work has been done to better understand the aerodynamics of compressor flow under distorted conditions and enable more distortion-tolerant designs to be evolved. Limited by the expenses shortage and the complexity of experiment, the data of inlet flow total pressure distortion are insufficient and more researches are necessarily needed on this subject [1].

Huang, J.; Wu, H.; Du, W. H.

142

On-site profiling and speciation of polycyclic aromatic hydrocarbons at manufactured gas plant sites by a high temperature transfer line, membrane inlet probe coupled to a photoionization detector and gas chromatograph/mass spectrometer.  

PubMed

A new high temperature transfer line, membrane inlet probe (HTTL-MIP) coupled to a photoionization detector (PID) and gas chromatograph/mass spectrometer (GC/MS) was used to rapidly profile and speciate polycyclic aromatic hydrocarbons (PAH) in the subsurface. PID signals were in agreement with GC/MS results. Correlation coefficients of 0.92 and 0.99 were obtained for discrete and composite samples collected from the same exact location. Continuous probe advancement with PID detection found coal tar, a dense nonaqueous phase liquid, in soil channels and saturated media. When samples were collected conventionally, split, solvent extracted, and analyzed in the field and confirmation laboratory, GC/MS measurement precision and accuracy were indistinguishable; despite the fact the field laboratory produced data five times faster than the laboratory using standard EPA methods. No false positive/negatives were found. Based on these findings, increased confidence in site conceptual models should be obtained, since PID response indicated total PAH presence/absence in "real-time", while GC/MS provided information as to which PAH was present and atwhat concentration. Incorporation of this tool into a dynamic workplan will provide more data at less cost enabling environmental scientists, engineers, and regulators to better understand coal tar migration and its impact on human health and the environment. PMID:18351095

Considine, Thomas; Robbat, Albert

2008-02-15

143

On-site profiling and speciation of polycyclic aromatic hydrocarbons at manufactured gas plant sites by a high temperature transfer line, membrane inlet probe coupled to a photoionization detector and gas chromatography/mass spectrometer  

SciTech Connect

A new high temperature transfer line, membrane inlet probe (HTTL-MIP) coupled to a photoionization detector (PID) and gas chromatograph/mass spectrometer (GC/MS) was used to rapidly profile and speciate polycyclic aromatic hydrocarbons (PAH) in the subsurface. PID signals were in agreement with GC/MS results. Correlation coefficients of 0.92 and 0.99 were obtained for discrete and composite samples collected from the same exact location. Continuous probe advancement with PID detection found coal tar, a dense nonaqueous phase liquid, in soil channels and saturated media. When samples were collected conventionally, split, solvent extracted, and analyzed in the field and confirmation laboratory, GC/MS measurement precision and accuracy were indistinguishable; despite the fact the field laboratory produced data five times faster than the laboratory using standard EPA methods. No false positive/negatives were found. Based on these findings, increased confidence in site conceptual models should be obtained, since PID response indicated total PAH presence/absence in 'real-time', while GC/MS provided information as to which PAH was present and at what concentration. Incorporation of this tool into a dynamic workplan will provide more data at less cost enabling environmental scientists, engineers, and regulators to better understand coal tar migration and its impact on human health and the environment. 24 refs., 3 figs., 4 tabs.

Thomas Considine; Albert Robbat Jr. [Tufts University, Medford, MA (United States). Chemistry Department, Center for Field Analytical Studies and Technology

2008-02-15

144

Flow rate and pressure profiles for 1 to 4 axially alined orifice inlets  

NASA Technical Reports Server (NTRS)

Choked flow rate and pressure profile data were taken on sequential axially alined inlets of the orifice type, with an orifice length-to-diameter ratio of 0.5. The configuration consisted of two to four inlets spaced at 0.66 and 32 orifice diameters apart. At a spacing of 32 diameters the reduced flow rate appeared to follow the simple power-law relation G(sub r)/G(sub r,1) = N (sup-b), where G(sub r,1) is the reduced flow rate for a single inlet, N is the number of inlets, and b, although temperature dependent, is approximately 0.4. At this spacing the instrumented orifices and spacers gave pressure profiles that dropped sharply at the entrance and partially recovered within each inlet, somewhat independent of N. At low inlet temperature jetting through the last orifice was common. At a spacing of 0.66 diameter fluid jetting through all N inlets was prevalent at low temperatures for each configuration studied, as indicated by the flat pressure profiles and flow rates that were nearlly identical to those for a single orifice inlet. A simplifying relation was developed between the friction loss parameters for flow through N sequential tubes and N sequential inlets. The predicted flow rates for N tubes were in reasonable agreement with the N inlet analysis and followed the simple power-law relation.

Hendricks, R. C.; Stetz, T. T.

1985-01-01

145

The effect of different inlet conditions of air in a rectangular channel on convection heat transfer: Turbulence flow  

Microsoft Academic Search

Theoretical and empirical correlations for duct flow are given for hydrodynamically and thermally developed flow in most of previous studies. However, this is commonly not a realistic inlet configuration for heat exchanger, in which coolant flow generally turns through a serpentine shaped passage before entering heat sinks. Accordingly, an experimental investigation was carried out to determine average heat transfer coefficients

Kurtbas; Irfan

2008-01-01

146

Design and Analysis Tools for Supersonic Inlets  

NASA Technical Reports Server (NTRS)

Computational tools are being developed for the design and analysis of supersonic inlets. The objective is to update existing tools and provide design and low-order aerodynamic analysis capability for advanced inlet concepts. The Inlet Tools effort includes aspects of creating an electronic database of inlet design information, a document describing inlet design and analysis methods, a geometry model for describing the shape of inlets, and computer tools that implement the geometry model and methods. The geometry model has a set of basic inlet shapes that include pitot, two-dimensional, axisymmetric, and stream-traced inlet shapes. The inlet model divides the inlet flow field into parts that facilitate the design and analysis methods. The inlet geometry model constructs the inlet surfaces through the generation and transformation of planar entities based on key inlet design factors. Future efforts will focus on developing the inlet geometry model, the inlet design and analysis methods, a Fortran 95 code to implement the model and methods. Other computational platforms, such as Java, will also be explored.

Slater, John W.; Folk, Thomas C.

2009-01-01

147

Method for removing cesium from a nuclear reactor coolant  

DOEpatents

A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium inventory thereof further into the carbon matrix while simultaneously redispersing a portion into the regeneration system for absorption at a reduced temperature by the secondary trap.

Colburn, R.P.

1983-08-10

148

1996 Coolant Flow Management Workshop  

NASA Technical Reports Server (NTRS)

The following compilation of documents includes a list of the 66 attendees, a copy of the viewgraphs presented, and a summary of the discussions held after each session at the 1996 Coolant Flow Management Workshop held at the Ohio Aerospace Institute, adjacent to the NASA Lewis Research Center, Cleveland, Ohio on December 12-13, 1996. The workshop was organized by H. Joseph Gladden and Steven A. Hippensteele of NASA Lewis Research Center. Participants in this workshop included Coolant Flow Management team members from NASA Lewis, their support service contractors, the turbine engine companies, and the universities. The participants were involved with research projects, contracts and grants relating to: (1) details of turbine internal passages, (2) computational film cooling capabilities, and (3) the effects of heat transfer on both sides. The purpose of the workshop was to assemble the team members, along with others who work in gas turbine cooling research, to discuss needed research and recommend approaches that can be incorporated into the Center's Coolant Flow Management program. The workshop was divided into three sessions: (1) Internal Coolant Passage Presentations, (2) Film Cooling Presentations, and (3) Coolant Flow Integration and Optimization. Following each session there was a group discussion period.

Hippensteele, Steven A. (Editor)

1997-01-01

149

IPAC-Inlet Performance Analysis Code  

NASA Technical Reports Server (NTRS)

A series of analyses have been developed which permit the calculation of the performance of common inlet designs. The methods presented are useful for determining the inlet weight flows, total pressure recovery, and aerodynamic drag coefficients for given inlet geometric designs. Limited geometric input data is required to use this inlet performance prediction methodology. The analyses presented here may also be used to perform inlet preliminary design studies. The calculated inlet performance parameters may be used in subsequent engine cycle analyses or installed engine performance calculations for existing uninstalled engine data.

Barnhart, Paul J.

1997-01-01

150

Inlet Flow Valve Engine Analyses  

NASA Technical Reports Server (NTRS)

Pratt&Whitney, under Task Order 13 of the NASA Large Engine Technology (LET) Contract, conducted a study to determine the operating characteristics, performance and weights of Inlet Flow Valve (IFV) propulsion concepts for a Mach 2.4 High Speed Civil Transport (HSCT).

Champagne, G. A.

2004-01-01

151

TiAl Scramjet Inlet Flap Subelement Designed and Fabricated  

NASA Technical Reports Server (NTRS)

Next-generation launch vehicles are being designed with turbine-based combined cycle (TBCC) propulsion systems having very aggressive thrust/weight targets and long lives. Achievement of these goals requires advanced materials in a wide spectrum of components. TiAl has been identified as a potential backstructure material for maintainable composite panel heat exchangers (HEX) in the inlet, combustor, and nozzle section of a TBCC propulsion system. Weight reduction is the primary objective of this technology. Design tradeoff studies have assessed that a TiAl structure, utilizing a high-strength, hightemperature TiAl alloy called Gamma MET PX,1 reduce weight by 41 to 48 percent in comparison to the baseline Inconel 718 configuration for the TBCC propulsion system inlet, combustor, and nozzle. A collaborative effort between the NASA Glenn Research Center, Pratt & Whitney, Engineering Evaluation & Design, PLANSEE AG (Austria), and the Austrian Space Agency was undertaken to design, manufacture, and validate a Gamma-MET PX TiAl structure for scramjet applications. The TiAl inlet flap was designed with segmented flaps to improve manufacturability, to better control thermal distortion and thermal stresses, and to allow for maintainable HEX segments. The design philosophy was to avoid excessively complicated shapes, to minimize the number of stress concentrations, to keep the part sizes reasonable to match processing capabilities, and to avoid risky processes such as welding. The conceptual design used a standard HEX approach with a double-pass coolant concept for centrally located manifolds. The flowpath side was actively cooled, and an insulation package was placed on the external side to save weight. The inlet flap was analyzed structurally, and local high-stress regions were addressed with local reinforcements.

Draper, Susan L.

2004-01-01

152

Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet.  

PubMed

This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, ?-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples. PMID:24896880

Lutomski, Corinne A; El-Baba, Tarick J; Inutan, Ellen D; Manly, Cory D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

2014-07-01

153

Interactions between an organic coolant and drops of molten lithium  

SciTech Connect

Twenty scoping experiments were performed to investigate the behavior of nominally 0.5 g molten lithium drops when released into 0.7 L of the organic coolant Therminol 66 at local atmospheric pressure using a vortex insertion technique. Diagnostics consisted of video and photographic imaging and several chemical analyses. Six coolant/Li temperature pairs were used: 300/300; 300/530; 300/770; 464/530; 600/530 and 600/770, all nominal in K. Because the coolant: Li weight ratio was 10{sup 3}, only rapid ({approximately}0.5 s) quenching reactions could be studied when T{sub Li} > {Tc}; when T{sub Li} {le} {Tc}, however, both rapid and slower (min) interactions could be investigated. In none of the experiments was there any indication of (a) a vigorous, self-sustaining chemical reaction between the lithium and the organic coolant, or (b) the formation of water-insoluble debris, in particular carbon. This work confirms the benign behavior at similar temperatures reported earlier by others.

Nelson, L.S.; Krueger, J.D.; Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

1994-11-01

154

Experiments on flow through one to four inlets of the orifice and Borda type  

NASA Technical Reports Server (NTRS)

Choked flow rate and pressure profile data were taken on sequential axially aligned inlets of the orifice and Borda type. The configuration consisted of from two to four inlets spaced at two nominal separation distances of 0.7 and 30 diameters. At the nominal 30 diameter spacing, the reduced flow rate follows a simple empirical relation based on the reduced flow rate for a single inlet. At the nominal 0.7 diameter spacing, fluid jetting was prevalent at low temperatures and flow rates were the same as for a single inlet. Previously announced in STAR as N81-30391

Hendricks, R. C.; Stetz, T. T.

1982-01-01

155

Experiments on flow through one to four inlets of the orifice and Borda type  

NASA Technical Reports Server (NTRS)

Choked flow rate and pressure profile data were taken on sequential axially aligned inlets of the orifice and Borda type. The configuration consisted of from two to four inlets spaced at two nominal separation distances of 0.7 and 30 diameters. At the nominal 30 diameter spacing, the reduced flow rate follows a simple empirical relation based on the reduced flow rate for a single inlet. At the nominal 0.7 diameter spacing, fluid jetting was prevalent at low temperatures and flow rates were the same as for a single inlet.

Hendricks, R. C.; Stetz, T. T.

1981-01-01

156

Combustion engine with additional air inlet valve  

Microsoft Academic Search

A combustion engine equipped with an additional air-inlet means and a control arrangement for closing and opening the inlet is described that results in more efficient combustion and favorable limitation of carbon monoxide and nitrogen oxide formation. The scope of the invention covers cylindrical, lifting, or rotary piston arrangements. The additional air inlet and its associated cam controlling device allow

Gospodar

1974-01-01

157

System and method for determining coolant level and flow velocity in a nuclear reactor  

DOEpatents

A boiling water reactor includes a reactor pressure vessel having a feedwater inlet for the introduction of recycled steam condensate and/or makeup coolant into the vessel, and a steam outlet for the discharge of produced steam for appropriate work. A fuel core is located within a lower area of the pressure vessel. The fuel core is surrounded by a core shroud spaced inward from the wall of the pressure vessel to provide an annular downcomer forming a coolant flow path between the vessel wall and the core shroud. A probe system that includes a combination of conductivity/resistivity probes and/or one or more time-domain reflectometer (TDR) probes is at least partially located within the downcomer. The probe system measures the coolant level and flow velocity within the downcomer.

Brisson, Bruce William; Morris, William Guy; Zheng, Danian; Monk, David James; Fang, Biao; Surman, Cheryl Margaret; Anderson, David Deloyd

2013-09-10

158

Heat transfer to two-phase air/water mixtures flowing in small tubes with inlet disequilibrium  

NASA Technical Reports Server (NTRS)

The cooling of gas turbine components was the subject of considerable research. The problem is difficult because the available coolant, compressor bleed air, is itself quite hot and has relatively poor thermophysical properties for a coolant. Injecting liquid water to evaporatively cool the air prior to its contact with the hot components was proposed and studied, particularly as a method of cooling for contingency power applications. Injection of a small quantity of cold liquid water into a relatively hot coolant air stream such that evaporation of the liquid is still in process when the coolant contacts the hot component was studied. No approach was found whereby heat transfer characteristics could be confidently predicted for such a case based solely on prior studies. It was not clear whether disequilibrium between phases at the inlet to the hot component section would improve cooling relative to that obtained where equilibrium was established prior to contact with the hot surface.

Janssen, J. M.; Florschuetz, L. W.; Fiszdon, J. P.

1986-01-01

159

Generic Hypersonic Inlet Module Analysis  

NASA Technical Reports Server (NTRS)

A computational study associated with an internal inlet drag analysis was performed for a generic hypersonic inlet module. The purpose of this study was to determine the feasibility of computing the internal drag force for a generic scramjet engine module using computational methods. The computational study consisted of obtaining two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) solutions using the Euler and parabolized Navier-Stokes (PNS) equations. The solution accuracy was assessed by comparisons with experimental pitot pressure data. The CFD analysis indicates that the 3D PNS solutions show the best agreement with experimental pitot pressure data. The internal inlet drag analysis consisted of obtaining drag force predictions based on experimental data and 3D CFD solutions. A comparative assessment of each of the drag prediction methods is made and the sensitivity of CFD drag values to computational procedures is documented. The analysis indicates that the CFD drag predictions are highly sensitive to the computational procedure used.

Cockrell, Chares E., Jr.; Huebner, Lawrence D.

2004-01-01

160

Optimal control of a supersonic inlet to minimize frequency of inlet unstart  

NASA Technical Reports Server (NTRS)

A preliminary investigation into the use of modern control theory for the design of controls for a supersonic inlet is described. In particular, the task of controlling a mixed-compression supersonic inlet is formulated as a linear optimal stochastic control and estimation problem. An inlet can exhibit an undesirable instability due to excessive inlet normal shock motion. For the optimal control formulation of the inlet problem, a non quadratic performance index, which is equal to the expected frequency of inlet unstarts, is used. This physically meaningful performance index is minimized for a range of inlet disturbance and measurement noise covariances.

Lehtinen, B.; Zeller, J. R.; Geyser, L. C.

1978-01-01

161

Thermal analysis of engine inlet anti-icing systems  

NASA Technical Reports Server (NTRS)

A hot air anti-icing system of a gas turbine engine inlet is analyzed numerically. A three-dimensional potential flow code, which accounts for compressibility effects, is used to determine the flowfield in and around the inlet. A particle trajectory code is developed using a local linearization technique. The trajectory code is used to calculate local water impingement rates. Energy balances are performed on both the surface runback water and the metallic skin to determine their temperature distributions. A variety of test cases are considered in order to validate the various numerical components of the process as well as to demonstrate the procedure.

Keith, Theo G., Jr.; De Witt, Kenneth J.; Nathman, James K.; Dietrich, Donald A.; Al-Khalil, Kamel M.

1989-01-01

162

Steady-state temperature distribution within a Brayton rotating unit operating in a power conversion system using helium-xenon gas  

NASA Technical Reports Server (NTRS)

The Brayton rotating unit (BRU), consisting of a turbine, an alternator, and a compressor, was tested as part of a Brayton cycle power conversion system over a side range of steady state operating conditions. The working fluid in the system was a mixture of helium-xenon gases. Turbine inlet temperature was varied from 1200 to 1600 F, compressor inlet temperature from 60 to 120 F, compressor discharge pressure from 20 to 45 psia, rotative speed from 32 400 to 39 600 rpm, and alternator liquid-coolant flow rate from 0.01 to 0.27 pound per second. Test results indicated that the BRU internal temperatures were highly sensitive to alternator coolant flow below the design value of 0.12 pound per second but much less so at higher values. The armature winding temperature was not influenced significantly by turbine inlet temperature, but was sensitive, up to 20 F per kVA alternator output, to varying alternator output. When only the rotational speed was changed (+ or - 10% of rated value), the BRU internal temperatures varied directly with the speed.

Johnsen, R. L.; Namkoong, D.; Edkin, R. A.

1971-01-01

163

Nuclear reactor with a liquid coolant  

Microsoft Academic Search

A nuclear reactor is disclosed with a hydrogen-containing liquid coolant loop having an expansion tank for the coolant, a high pressure pump having a suction side and feeding coolant taken from the loop back into the loop after purification, a line bypassing the expansion tank and being connected to the suction side of the high-pressure pump, and means for introducing

E. Schick; P. Wisniewski

1983-01-01

164

Nuclear reactor having a liquid coolant  

Microsoft Academic Search

Nuclear reactor with a liquid coolant loop having a volume control surge tank for the coolant disposed in the loop, and a high pressure pump disposed in the loop for feeding coolant taken from the loop back into the loop after purification. A line bypassing the volume control surge tank and having an end connected to the suction side of

H. Deinlein; G. Kummer

1983-01-01

165

Nose and inlet duct radomes for the firebolt aerial target  

NASA Astrophysics Data System (ADS)

Radomes of the Firebolt Aerial Target (AQM-81A) facilitate an uncommon set of operational conditions. The target vehicle is first carried captively. Stones may be dislodged from the runway and impact the Nose or Inlet Duct Radomes with considerable force. The drone has various flight profiles after launch, encompassing levels of MACH 1.2 at 35,000 feet to MACH 4 at 100,000 feet. For flights of 10 minutes, attendant aerothermal loads produce temperature peaks of 680 deg F and 980 deg F for the Nose and Inlet Duct units, respectively. Firebolt is normally retrieved, by helicopter after its parachute deploys, for refurbishment and re-use. Occasionally, sea recovery is effected using flotation gear. Electrically, the Nose Radome accommodates an L-band antenna for the electronic scoring system, and a small circulary polarized X-band horn. The Inlet Duct Radome houses an identical broad-beamed horn.

Hoots, L. C.

166

The Integral Vapor Compression and Liquid Coolant refrigeration system  

NASA Astrophysics Data System (ADS)

The Integral Vapor Compression and Liquid (IVCL) coolant system developed by McDonnell Aircraft Company is described. The system operates on an innovative thermodynamic cycle that combines refrigeration and liquid coolant heat transport functions. Both analytical and empirical investigations show that the IVCL refrigeration system is technically feasible. When operating with low heat sink flow rates the performance coefficient of the IVCL systems and the maximum attainable heat sink temperature are significantly greater than those of a comparable mechanical vapor compression cycle refrigeration system. The IVCL system superior performance at low heat sink flow rates can provide major benefits in terms of improving tactical aircraft thermal management.

Siems, David L.

1992-07-01

167

Coupled inlet-engine dynamic analysis method  

NASA Astrophysics Data System (ADS)

A new method is presented for unsteady analysis of turbine engine propulsion systems. The method is a coupled analysis of the inlet-compressor combination with multidimensional inlet capability. The method incorporates inviscid, unsteady, computational fluid dynamics in the inlet using an unstructured numerical grid and a one-dimensional dynamic turbomachinery model. The present application of the method is an axisymmetric mixed compression inlet with an eight stage axial compressor of a turbojet engine. The inlet simulation includes geometric details not previously included in strictly one-dimensional analyses. Simulation of two events are compared to experimental data for Mach 2.5 freestream conditions. The first event is an inlet unstart triggered by bypass flow throttling, resulting in a subsequent compressor stall. The second event is a compressor stall triggered by nozzle throttling resulting in a subsequent inlet unstart and strong hammershock. Good agreement with the experiment is achieved in both cases.

Numbers, Keith E.

168

Numerical analysis of turbulent heat transfer in a nuclear reactor coolant channel  

E-print Network

NUMERICAL ANALYSIS OF TURBULENT HEAT TRANSFER IN A NUCLEAR REACTOR COOLANT CHANNEL A Thesis Clarence William Garrard, Jr. Submitted to the Graduate College of the Texas A&M University in partial fulfillment of' the requirements for the degree... for Re ? 53, 000 10 Local Heat Transfer Coefficients Along the Coolant Channel Axial Bulk Kean Temperature Profile Axial Hall Temperature Profile Axis. l T~& ? Tb Temperature Prof i le 30 31 32 33 CHAPTER I INTRODUCTION As the power level...

Garrard, Clarence William

1965-01-01

169

Oregon inlet: Hydrodynamics, volumetric flux and implications for larval fish transport  

SciTech Connect

The temporal response of Oregon Inlet currents to atmospheric forcing and sea level fluctuations is analyzed using time and frequency domain analysis. Temporally persistent and spatially extensive ebb and flood events are identified using data sets from both within and outside of Oregon Inlet. Prism estimates are made to generate a time series of volumetric flux of water transported through the inlet. Water masses flooding into the Pamlico Sound via Oregon Inlet are identified in temperature (T) and salinity (S) space to determine their source of origin. Correlations are examined between the atmospheric wind field, the main axial slope of the inlet`s water level, inlet flow and T, S properties. Synoptic scale atmospheric wind events are found to dramatically and directly affect the transport of water towards (away from) the inlet on the ocean side, in concert with the contemporaneous transport away from (towards) the inlet on the estuary side, and a subsequent flooding into (out of) the estuary via Oregon Inlet. Thus, while astronomical tidal flooding and ebbing events are shown to be one-sided as coastal waters either set-up or set-down, synoptic scale wind events are shown to be manifested as a two-sided in-phase response set-up and set-down inside and outside the inlet, and thus are extremely effective in driving currents through the inlet. These subinertial frequency flood events are believed to be essential for both the recruitment and subsequent retention of estuarine dependent larval fish from the coastal ocean into Pamlico Sound. Year class strength of these finish may be determined annually by the relative strength and timing of these climatological wind events.

Nichols, C.R. [National Oceanic and Atmospheric Administration, Silver Springs, MD (United States); Pietrafesa, L.J. [North Carolina State Univ., Raleigh, NC (United States). Department of Marine, Earth and Atmospheric Sciences

1997-05-01

170

Low-speed performance of an axisymmetric, mixed-compression, supersonic inlet with auxiliary inlets  

NASA Technical Reports Server (NTRS)

A test program was conducted to determine the aerodynamic performance and acoustic characteristics associated with the low-speed operation of a supersonic, axisymmetric, mixed-compression inlet with auxiliary inlets. Blow-in-auxiliary doors were installed on the NASA Ames P inlet. One door per quadrant was located on the cowl in the subsonic diffuser selection of the inlet. Auxiliary inlets with areas of 20 and 40 percent of the inlet capture area were tested statically and at free-stream Mach numbers of 0.1 and 0.2. The effects of boundary layer bleed inflow were investigated. A JT8D fan simulator driven by compressed air was used to pump inlet flow and to provide a characteristic noise signature. Baseline data were obtained at static free-stream conditions with the sharp P-inlet cowl lip replaced by a blunt lip. Auxiliary inlets increased overall total pressure recovery of the order of 10 percent.

Trefny, C. J.; Wasserbauer, J. W.

1986-01-01

171

Flow tests of a single fuel element coolant channel for a compact fast reactor for space power  

NASA Technical Reports Server (NTRS)

Water flow tests were conducted on a single-fuel-element cooling channel for a nuclear concept to be used for space power. The tests established a method for measuring coolant flow rate which is applicable to water flow testing of a complete mockup of the reference reactor. The inlet plenum-to-outlet plenum pressure drop, which approximates the overall core pressure drop, was measured and correlated with flow rate. This information can be used for reactor coolant flow and heat transfer calculations. An analytical study of the flow characteristics was also conducted.

Springborn, R. H.

1971-01-01

172

Overview of the Light Aircraft Aerosol Research Inlet (LAARI)  

NASA Astrophysics Data System (ADS)

Aircraft provide a mobile platform for measuring vertical profile aerosol properties. The efficacy of these measurements, however, is constrained by the aerosol inlet sampling efficiency. Larger particles are often lost to turbulent deposition and impaction inside the inlet and sampling lines, respectively. This precludes the measurement of coarse mode particles, important to visibility and radiative transfer studies. Turbulent deposition of large particles occurs when the sample air stream slows down within the inlet from the aircraft velocity to the recommended sampling velocities of the aerosol instruments (\\sim10 m s-1). Low-turbulence inlets that reduce turbulent deposition through the use of a porous diffuser cones are necessary for large aircraft with air speeds of 80 to 200 m s-1, but these are not feasible for light aircraft because of space and power requirements and may not even be necessary given the low air speeds of small aircraft. We have designed an aerosol inlet for a light aircraft platform with an average air speed of 60 m s-1 and a sample flow rate of 28.5 L min-1. The hemi-elliptical shaped, stainless steel inlet is 12.7 cm long. The front orifice has a 0.3175 cm diameter and the internal diameter expands to 0.9525 cm over a length of 9.2075 cm at an included angle of 4.3\\deg. The linear velocity of the sample stream as it exits the inlet is 6.7 m s-1. The calculated Reynolds number (Re) at the opening is 11,430 and decreases to 3,811 at the inlet terminus, with a pressure drop across the inlet opening of only 42 mb at an average flight temperature and pressure. Sampling line impaction is reduced by decreasing the number of bends upstream of the instruments. We have accomplished this by designing a parallel sampling manifold that splits the sample stream into four separate streams, three of which are split from the primary sample stream at an angle of 15\\deg. Theoretical investigations of sample flow and particle losses are underway with Computational Fluid Dynamics (CFD) software from FlowLab. Wind tunnel analyses using a Vibrating Orifice Aerosol Generator (VOAG) with optical particle counters upstream and downstream of the inlet and sampling lines will validate the theoretical calculations and provide empirical sampling efficiency values. This new inlet design will facilitate the more efficient collection of ambient particles, especially those in the coarse mode, from light aircraft. Because light aircraft are less expensive to operate than large aircraft and can make measurements in the lower atmosphere on a more routine basis, the Light Aircraft Aerosol Research Inlet (LAARI) will herald a new era of measurement capabilities in satellite validation work, column closure tests, and climate change studies.

Bueno, P. A.; Taubman, B. F.; Marufu, L. T.

2004-12-01

173

Planar Inlet Design and Analysis Process (PINDAP)  

NASA Technical Reports Server (NTRS)

The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

Slater, John W.; Gruber, Christopher R.

2005-01-01

174

Axisymmetric inlet minimum weight design method  

NASA Technical Reports Server (NTRS)

An analytical method for determining the minimum weight design of an axisymmetric supersonic inlet has been developed. The goal of this method development project was to improve the ability to predict the weight of high-speed inlets in conceptual and preliminary design. The initial model was developed using information that was available from inlet conceptual design tools (e.g., the inlet internal and external geometries and pressure distributions). Stiffened shell construction was assumed. Mass properties were computed by analyzing a parametric cubic curve representation of the inlet geometry. Design loads and stresses were developed at analysis stations along the length of the inlet. The equivalent minimum structural thicknesses for both shell and frame structures required to support the maximum loads produced by various load conditions were then determined. Preliminary results indicated that inlet hammershock pressures produced the critical design load condition for a significant portion of the inlet. By improving the accuracy of inlet weight predictions, the method will improve the fidelity of propulsion and vehicle design studies and increase the accuracy of weight versus cost studies.

Nadell, Shari-Beth

1995-01-01

175

Radial inlet guide vanes for a combustor  

DOEpatents

A combustor may include an interior flow path therethrough, a number of fuel nozzles in communication with the interior flow path, and an inlet guide vane system positioned about the interior flow path to create a swirled flow therein. The inlet guide vane system may include a number of windows positioned circumferentially around the fuel nozzles. The inlet guide vane system may also include a number of inlet guide vanes positioned circumferentially around the fuel nozzles and adjacent to the windows to create a swirled flow within the interior flow path.

Zuo, Baifang; Simons, Derrick; York, William; Ziminsky, Willy S

2013-02-12

176

Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors  

NASA Technical Reports Server (NTRS)

A model supersonic inlet with auxiliary inlet doors and bounday layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9x15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression.

Woodward, R. P.; Glaser, F. W.; Lucas, J. G.

1982-01-01

177

Active Flow Control For Inlets  

NASA Technical Reports Server (NTRS)

This presentation describes the progress to date of the Small-Scale Demonstration for the Active Flow Control element of the Propulsion Airframe Integration Project. The goal of this work package is to demonstrate at small scale the ability to improve pressure recovery and distortion in an S-inlet with boundary layer ingestion representative of a Blended Wing Body (BWB) configuration. The effectiveness of several active and passive devices to control flow in an adverse pressure gradient with secondary flows present was evaluated in the Langley 15-Inch Low-Turbulence Tunnel. In this study, passive microvanes, microbumps, and piezoelectric synthetic jets were evaluated for their flow control characteristics using surface static pressures, flow visualization, and 3D Stereo Digital Particle Image Velocimetry. The microvanes imparted a higher level of vorticity to the flow than any of the other devices tested. Alternative actuator concepts are being pursued to support the Small-Scale Demonstration Level 1 milestone in FY03.

Gorton, Susan A.

2001-01-01

178

Experimental investigation of a submerged subsonic inlet  

NASA Astrophysics Data System (ADS)

The goal of combined computational and experimental study is the design optimization of a generic submerged inlet, which minimizes flow distortion at the engine face. A series of experimental surveys were performed to validate the accompanying computations and to provide additional information regarding the Pareto Set of optimal designs. The objectives of experimental investigation are to: (1) perform comparison between experimental and accompanying computed Distortion Coefficients (DC) for the baseline and one of the inlets from the Pareto Set of optimal designs for zero angle of attack and angle of sideslip, (2) assess the sensitivity of the measured DC's for both inlets for nonzero angle of attack and angle of sideslip and (3) examine the flowfield structure (mean velocity and turbulence levels within inlets). Detailed experiments using pressure differential technique (with the accuracy of +/-3%) were focused on the measurements of total pressure three diameters downstream of the exit of the inlet. A hot wire thermal anemometry system was employed to verify velocity profiles obtained using the pressure differential technique and to assess the sensitivity of the turbulence structure to the change in inlet geometry. The accuracy of those measurements was +/-5%. Experimental evaluation of the baseline and optimum inlet for zero angle of attack and yaw showed a consistent trend between experimental and computational results in reduction of the DC. Also, the DC improved for the optimum inlet compared to the baseline inlet for negative angles of attack and all yaw angles. The optimum inlet, which introduced fins within the inlet, decreased the turbulence levels for zero and negative and increased turbulence levels for positive angles of attack (consistent with the DC). In addition, the experimental evaluations for nonzero angles of attack and yaw were performed with minimum additional effort, much faster than it would take to perform the corresponding computational study.

Jovanovic, Vasilije J.

179

Field Data Collection at Coastal Inlets  

Microsoft Academic Search

BACKGROUND: Coastal inlets are the conduits for water, material, and small waterborne animals and plants between the oceans and bays, estuaries, and lagoons. The Operation and Maintenance (O&M) activities of the U.S. Army Corps of Engineers (USACE) involve navigation channel dredging and preservation of the beaches adjacent to inlets, as well as preservation of water quality and environmental conditions (USACE

Thad C. Pratt; Timothy L. Fagerburg; Darla C. McVan

180

Multiple-Inlet/Single-Outlet Orifice Plate  

NASA Technical Reports Server (NTRS)

Orifice plate for control of flow has multiple slanted inlets leading to single outlet. Multiple-inlet/single-outlet orifice less susceptible to blockage than single hole drilled through plate perpendicular to its surface. Easily calibrated for various flow rates and fits in place of simple orifice plate with no other modifications.

Godown, Robert L.

1990-01-01

181

External-Compression Supersonic Inlet Design Code  

NASA Technical Reports Server (NTRS)

A computer code named SUPIN has been developed to perform aerodynamic design and analysis of external-compression, supersonic inlets. The baseline set of inlets include axisymmetric pitot, two-dimensional single-duct, axisymmetric outward-turning, and two-dimensional bifurcated-duct inlets. The aerodynamic methods are based on low-fidelity analytical and numerical procedures. The geometric methods are based on planar geometry elements. SUPIN has three modes of operation: 1) generate the inlet geometry from a explicit set of geometry information, 2) size and design the inlet geometry and analyze the aerodynamic performance, and 3) compute the aerodynamic performance of a specified inlet geometry. The aerodynamic performance quantities includes inlet flow rates, total pressure recovery, and drag. The geometry output from SUPIN includes inlet dimensions, cross-sectional areas, coordinates of planar profiles, and surface grids suitable for input to grid generators for analysis by computational fluid dynamics (CFD) methods. The input data file for SUPIN and the output file from SUPIN are text (ASCII) files. The surface grid files are output as formatted Plot3D or stereolithography (STL) files. SUPIN executes in batch mode and is available as a Microsoft Windows executable and Fortran95 source code with a makefile for Linux.

Slater, John W.

2011-01-01

182

Electrically heated particulate matter filter with recessed inlet end plugs  

DOEpatents

A particulate matter (PM) filter includes filter walls having inlet ends and outlet ends. First adjacent pairs of the filter walls define inlet channels. Second adjacent pairs of the filter walls define outlet channels. Outlet end plugs are arranged in the inlet channels adjacent to the output ends. Inlet end plugs arranged in the outlet channels spaced from the inlet ends.

Gonze, Eugene V. (Pinckney, MI); Ament, Frank (Troy, MI)

2012-02-21

183

Hydrodynamics and equilibrium of a multiple-inlet system  

Microsoft Academic Search

Although it is generally acknowledged that most multiple inlets are unstable and cannot coexist, there is evidence to suggest that such inlets can indeed be stable over decadal time scales. Multiple-inlet systems servicing a single embayment, in contrast to single-inlet systems, confer particular hydrodynamic characteristics such as the potential existence of residual discharges and currents between the inlets. This paper

A. Pacheco; Ó. Ferreira; J. J. Williams; E. Garel; A. Vila-Concejo; J. A. Dias

2010-01-01

184

Cleaning of uranium vs machine coolant formulations  

SciTech Connect

This study compares methods for cleaning uranium chips and the residues left on chips from alternate machine coolants based on propylene glycol-water mixtures with either borax, ammonium tetraborate, or triethanolamine tetraborate added as a nuclear poison. Residues left on uranium surfaces machined with perchloroethylene-mineral oil coolant and on surfaces machined with the borax-containing alternate coolant were also compared. In comparing machined surfaces, greater chlorine contamination was found on the surface of the perchloroethylene-mineral oil machined surfaces, but slightly greater oxidation was found on the surfaces machined with the alternate borax-containing coolant. Overall, the differences were small and a change to the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.

Cristy, S.S.; Byrd, V.R.; Simandl, R.F.

1984-10-01

185

Research on Supersonic Inlet Bleed  

NASA Technical Reports Server (NTRS)

Phase I data results of the Fundamental Inlet Bleed Experiments project at NASA Glenn Research Center (GRC) are presented which include flow coefficient results for two single-hole boundary-layer bleed configurations. The bleed configurations tested are round holes at inclination angles of 90deg and 20deg both having length-to-diameter ratios of 2.0. Results were obtained at freestream Mach numbers of 1.33, 1.62, 1.98, 2.46, and 2.92 and unit Reynolds numbers of 0.984, 1.89, and 2.46 10(exp 7)/m. Approach boundary-layer data are presented for each flow condition and the flow coefficient results are compared to existing multi-hole data obtained under similar conditions. For the 90deg hole, the single and multi-hole distributions agree fairly well with the exception that under supercritical operation, the multi-hole data chokes at higher flow coefficient levels. This behavior is also observed for the 20deg hole but to a lesser extent. The 20deg hole also shows a markedly different characteristic at subcritical operation. Also presented are preliminary results of a Computational Fluid Dynamics (CFD) analysis of both configurations at the Mach 1.33 and a unit Reynolds number of 2.46 10(exp 7)/m. Comparison of the results shows the agreement to be very good.

Davis, David O.; Vyas, Manan A.; Slater, John W.

2012-01-01

186

14 CFR 25.941 - Inlet, engine, and exhaust compatibility.  

Code of Federal Regulations, 2014 CFR

... General § 25.941 Inlet, engine, and exhaust compatibility. For airplanes using variable inlet or exhaust system geometry, or both— (a) The system comprised of the inlet, engine (including thrust augmentation systems, if...

2014-01-01

187

14 CFR 25.941 - Inlet, engine, and exhaust compatibility.  

Code of Federal Regulations, 2010 CFR

... General § 25.941 Inlet, engine, and exhaust compatibility. For airplanes using variable inlet or exhaust system geometry, or both— (a) The system comprised of the inlet, engine (including thrust augmentation systems, if...

2010-01-01

188

14 CFR 25.941 - Inlet, engine, and exhaust compatibility.  

Code of Federal Regulations, 2013 CFR

... General § 25.941 Inlet, engine, and exhaust compatibility. For airplanes using variable inlet or exhaust system geometry, or both— (a) The system comprised of the inlet, engine (including thrust augmentation systems, if...

2013-01-01

189

49 CFR 178.337-8 - Openings, inlets, and outlets.  

Code of Federal Regulations, 2014 CFR

...tanks except for those used to transport chlorine. The requirements for inlets and outlets on chlorine cargo tanks are in paragraph (b) of this... (b) Inlets and discharge outlets on chlorine tanks. The inlet and discharge...

2014-10-01

190

Observations of wave effects on inlet circulation  

NASA Astrophysics Data System (ADS)

Observations of water levels, winds, waves, and currents in Katama Bay, Edgartown Channel, and Katama Inlet on Martha's Vineyard, Massachusetts are used to test the hypothesis that wave forcing is important to circulation in inlet channels of two-inlet systems and to water levels in the bay between the inlets. Katama Bay is connected to the Atlantic Ocean via Katama Inlet and to Vineyard Sound via Edgartown Channel. A numerical model based on the momentum and continuity equations that uses measured bathymetry and is driven with observed water levels in the ocean and sound, ocean waves, and local winds predicts the currents observed in Katama Inlet more accurately when wave forcing is included than when waves are ignored. During Hurricanes Irene and Sandy, when incident (12-m water depth) significant wave heights were greater than 5 m, breaking-wave cross-shore (along-inlet-channel) radiation stress gradients enhanced flows from the ocean into the bay during flood tides, and reduced (almost to zero during Irene) flows out of the bay during ebb tides. Model simulations without the effects of waves predict net discharge from the sound to the ocean both during Hurricane Irene and over a 1-month period with a range of conditions. In contrast, simulations that include wave forcing predict net discharge from the ocean to the sound, consistent with the observations.

Orescanin, Mara; Raubenheimer, Britt; Elgar, Steve

2014-07-01

191

Boundary-Layer-Ingesting Inlet Flow Control  

NASA Technical Reports Server (NTRS)

This paper gives an overview of a research study conducted in support of the small-scale demonstration of an active flow control system for a boundary-layer-ingesting (BLI) inlet. The effectiveness of active flow control in reducing engine inlet circumferential distortion was assessed using a 2.5% scale model of a 35% boundary-layer-ingesting flush-mounted, offset, diffusing inlet. This experiment was conducted in the NASA Langley 0.3-meter Transonic Cryogenic Tunnel at flight Mach numbers with a model inlet specifically designed for this type of testing. High mass flow actuators controlled the flow through distributed control jets providing the active flow control. A vortex generator point design configuration was also tested for comparison purposes and to provide a means to examine a hybrid vortex generator and control jets configuration. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion and pressure recovery were determined by 40 total pressure measurements on 8 rake arms each separated by 45 degrees and were located at the aerodynamic interface plane. The test matrix was limited to a maximum free-stream Mach number of 0.85 with scaled mass flows through the inlet for that condition. The data show that the flow control jets alone can reduce circumferential distortion (DPCPavg) from 0.055 to about 0.015 using about 2.5% of inlet mass flow. The vortex generators also reduced the circumferential distortion from 0.055 to 0.010 near the inlet mass flow design point. Lower inlet mass flow settings with the vortex generator configuration produced higher distortion levels that were reduced to acceptable levels using a hybrid vortex generator/control jets configuration that required less than 1% of the inlet mass flow.

Owens, Lewis R.; Allan, Brian G.; Gorton, Susan A.

2006-01-01

192

Boundary-Layer-Ingesting Inlet Flow Control  

NASA Technical Reports Server (NTRS)

This paper gives an overview of a research study conducted in support of the small-scale demonstration of an active flow control system for a boundary-layer-ingesting (BLI) inlet. The effectiveness of active flow control in reducing engine inlet circumferential distortion was assessed using a 2.5% scale model of a 35% boundary-layer-ingesting flush-mounted, offset, diffusing inlet. This experiment was conducted in the NASA Langley 0.3-meter Transonic Cryogenic Tunnel at flight Mach numbers with a model inlet specifically designed for this type of testing. High mass flow actuators controlled the flow through distributed control jets providing the active flow control. A vortex generator point design configuration was also tested for comparison purposes and to provide a means to examine a hybrid vortex generator and control jets configuration. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion and pressure recovery were determined by 40 total pressure measurements on 8 rake arms each separated by 45 degrees and were located at the aerodynamic interface plane. The test matrix was limited to a maximum free-stream Mach number of 0.85 with scaled mass flows through the inlet for that condition. The data show that the flow control jets alone can reduce circumferential distortion (DPCP(sub avg)) from 0.055 to about 0.015 using about 2.5% of inlet mass flow. The vortex generators also reduced the circumferential distortion from 0.055 to 0.010 near the inlet mass flow design point. Lower inlet mass flow settings with the vortex generator configuration produced higher distortion levels that were reduced to acceptable levels using a hybrid vortex generator/control jets configuration that required less than 1% of the inlet mass flow.

Owens, Lewis R.; Allan, Brian G.; Gorton, Susan A.

2006-01-01

193

Turbine Inlet Analysis of Injected Water Droplet Behavior  

NASA Astrophysics Data System (ADS)

Gas turbines have become widely used in the generation of power for cities. They are used all over the world and must operate under a wide variety of ambient conditions. Every turbine has a temperature at which it operates at peak capacity. In order to attain this temperature in the hotter months various cooling methods are used such as refrigeration inlet cooling systems, evaporative methods, and thermal energy storage systems. One of the more widely used is the evaporative systems because it is one of the safest and easiest to utilize method. However, the behavior of water droplets within the inlet to the turbine has not been extensively studied or documented. It is important to understand how the droplets behave within the inlet so that water droplets above a critical diameter will not enter the compressor and cause damage to the compressor blades. In order to do this a FLUENT simulation was constructed in order to determine the behavior of the water droplets and if any droplets remain at the exit of the inlet, along with their size. In order to do this several engineering drawings were obtained from SRP and studies in order to obtain the correct dimensions. Then the simulation was set up using data obtained from SRP and Parker-Hannifin, the maker of the spray nozzles. Then several sets of simulations were run in order to see how the water droplets behaved under various conditions. These results were then analyzed and quantified so that they could be easily understood. The results showed that the possible damage to the compressor increased with increasing temperature at a constant relative humidity. This is due in part to the fact that in order to keep a constant relative humidity at varying temperatures the mass fraction of water vapor in the air must be changed. As temperature increases the water vapor mass fraction must increase in order to maintain a constant relative humidity. This in turn makes it slightly increases the evaporation time of the water droplets. This will then lead to more droplets exiting the inlet and at larger diameters.

Hargrave, Kevin

194

Bleed system design technology for supersonic inlets.  

NASA Technical Reports Server (NTRS)

A boundary layer bleed system design procedure for supersonic inlets, with emphasis on the selection of bleed hole geometry, is described. Available experimental bleed hole performance data, coupled with bleed drag calculations, show that holes with shallow inclination are superior to holes normal to the surface in terms of overall inlet performance. Recent test results from large-scale inlet models indicate that bleed hole size, bleed hole length, and boundary layer velocity profile upstream of the bleed region are important parameters in the design of an effective and efficient bleed system.

Syberg, J.; Koncsek, J. L.

1972-01-01

195

Airflow control system for supersonic inlets  

NASA Technical Reports Server (NTRS)

In addition to fixed and variable bleed devices provided for controlling the position of a terminal shock wave in a supersonic inlet, a plurality of free piston valves are disposed around the periphery of a cowling of a supersonic engine inlet. The free piston valves are disposed in dump passageways, each of which begin at a bleed port in the cowling that is located in the throat region of the inlet, where the diameter of the centerbody is near maximum, and terminates at an opening in the cowling adjacent a free piston valve. Each valve is controlled by reference pressure.

Mitchell, G. A. (inventor); Sanders, B. W.

1974-01-01

196

The Origin of Inlet Buzz in a Mach 1.7 Low Boom Inlet Design  

NASA Technical Reports Server (NTRS)

Supersonic inlets with external compression, having a good level performance at the critical operating point, exhibit a marked instability of the flow in some subcritical operation below a critical value of the capture mass flow ratio. This takes the form of severe oscillations of the shock system, commonly known as "buzz". The underlying purpose of this study is to indicate how Detached Eddy Simulation (DES) analysis of supersonic inlets will alter how we envision unsteady inlet aerodynamics, particularly inlet buzz. Presented in this paper is a discussion regarding the physical explanation underlying inlet buzz as indicated by DES analysis. It is the normal shock wave boundary layer separation along the spike surface which reduces the capture mass flow that is the controlling mechanism which determines the onset of inlet buzz, and it is the aerodynamic characteristics of a choked nozzle that provide the feedback mechanism that sustains the buzz cycle by imposing a fixed mean corrected inlet weight flow. Comparisons between the DES analysis of the Lockheed Martin Corporation (LMCO) N+2 inlet and schlieren photographs taken during the test of the Gulfstream Large Scale Low Boom (LSLB) inlet in the NASA 8x6 ft. Supersonic Wind Tunnel (SWT) show a strong similarity both in turbulent flow field structure and shock wave formation during the buzz cycle. This demonstrates the value of DES analysis for the design and understanding of supersonic inlets.

Anderson, Bernhard H.; Weir, Lois

2014-01-01

197

A Low-Cost Design and Flight Test of the T-38 Inlet  

NASA Technical Reports Server (NTRS)

An inlet redesign of the T-38 was completed and flight tested by NASA Johnson Space Center (JSC), Houston Texas. The redesign will allow full gross weight takeoffs from high altitude airports such as El Paso, Texas (ELP) with runway temperatures up to 99 degrees F, an increase of 9 degrees F over the current performance. This project was completed in-house using innovative test techniques. The static thrust of the T-38 was increased 20% with this new inlet.

Johnson, Greg; Ess, Robert

1997-01-01

198

Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.  

PubMed

A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions. PMID:25338207

Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing

2014-01-01

199

Effect of Inlet and Outlet Flow Conditions on Natural Gas Parameters in Supersonic Separation Process  

PubMed Central

A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions. PMID:25338207

Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing

2014-01-01

200

Computational analysis of ramjet engine inlet interaction  

NASA Technical Reports Server (NTRS)

A computational analysis of a ramjet engine at Mach 3.5 has been conducted and compared to results obtained experimentally. This study focuses on the behavior of the inlet both with and without combustor backpressure. Increased backpressure results in separation of the body side boundary layer and a resultant static pressure rise in the inlet throat region. The computational results compare well with the experimental data for static pressure distribution through the engine, inlet throat flow profiles, and mass capture. The computational analysis slightly underpredicts the thickness of the engine body surface boundary layer and the extent of the interaction caused by backpressure; however, the interaction is observed at approximately the same level of backpressure both experimentally and computationally. This study demonstrates the ability of two different Navier-Stokes codes, namely RPLUS and PARC, to calculate the flow features of this ramjet engine and to provide more detailed information on the process of inlet interaction and unstart.

Duncan, Beverly; Thomas, Scott

1992-01-01

201

The Peel Inlet-Harvey Estuary Study.  

ERIC Educational Resources Information Center

Describes how the department of physics of the Western Australian Institute of Technology (WAIT) has been involved in the Peel Inlet-Harvey Estuary study. An appendix which presents the departmental approach to curriculum matters is also included. (HM)

Walker, Warren; Black, Ronald

1979-01-01

202

Noise suppression with high Mach number inlets  

NASA Technical Reports Server (NTRS)

Experimental results were obtained for two types of high Mach number inlets, one with a translating centerbody and a fixed geometry inlet (collapsing cowl) with no centerbody. The aerodynamic and acoustic performance of these inlets was examined. The effects of area ratio, length/diameter ratio, and lip geometry were among several parameters investigated. The translating centerbody type inlet was found to be superior to the collapsing cowl both acoustically and aerodynamically, particularly for area ratios greater than 1.5. Comparison of length/diameter ratio and area ratio effects on performance near choked flow showed the latter to be more significant. Also, greater high frequency noise attenuation was achieved by increasing Mach number from low to high subsonic values.

Lumsdaine, E.; Cherng, J. G.; Tag, I.

1976-01-01

203

Two Stage Supersonic Inlet (TSSI):10-inch Model Calculations  

NASA Technical Reports Server (NTRS)

The bifurcated inlet examined in this study (which is one of several being considered in the High Speed Research (HSR) Program) was chosen based upon paper trade studies of axisymmetric, single sided, and bifurcated inlets. For a given compression ratio and mass flow a bifurcated inlet weighs less than a single sided inlet. An axisymmetric inlet has less bleed requirements than 2D inlets but has trouble matching transonic airflow requirements without going to a variable diameter centerbody. The bifurcated inlet was selected as one of the candidates because of its ability to match airflow schedules. The inlet examined in this study, the Two Stage Supersonic Inlet (TSSI), was a candidate mixed compression bifurcated inlet. It has a novel concept to aid in inlet stability. This concept was tested in the 10x10 wind tunnel at NASA Glenn. CFD tools were used to predict and interpret the experimental results.

Chapman, Dave (Technical Monitor); Smith, C. F.; Smith, G. E.

2005-01-01

204

Optimal Design of a Subsonic Submerged Inlet  

Microsoft Academic Search

A multi-objective optimization study based on an epsilon-constraint method is conducted for the design optimization of a subsonic submerged air vehicle inlet. The multi-objective optimization problem is reformulated by minimizing one of the objectives and restricting the other objectives within user specified values. The figures of merits are the engine-face distortion and swirl that determines the inlet\\/engine compatibility. The distortion

Ezgi Taskinoglu; Vasilije Jovanovic; Gregory Elliott; Doyle Knight

2003-01-01

205

Bi-coolant flat plate solar collector  

NASA Astrophysics Data System (ADS)

The feasibility study of a flat plate solar collector which heats air and water concurrently or separately was carried out. Air flows above the collector absorber plate, while water flows in tubes soldered or brazed beneath the plate. The collector efficiencies computed for the flow of both air and water are compared with those for the flow of a single coolant. The results show that the bi-coolant collector efficiency computed for the entire year in Buffalo, New York is higher than the single-coolant collector efficiency, although the efficiency of the water collector is higher during the warmer months.

Chon, W. Y.; Green, L. L.

206

Copper-triazole interaction and coolant inhibitor depletion  

SciTech Connect

To a large extent, the depletion of tolyltriazole (TTZ) observed in several field tests may be attributed to the formation of a protective copper-triazole layer. Laboratory aging studies, shown to correlate with field experience, reveal that copper-TTZ layer formation depletes coolant TTZ levels in a fashion analogous to changes observed in the field. XPS and TPD-MS characterization of the complex formed indicates a strong chemical bond between copper and the adsorbed TTZ which can be desorbed thermally only at elevated temperatures. Electrochemical polarization experiments indicate that the layer provides good copper protection even when TTZ is absent from the coolant phase. Examination of copper cooling system components obtained after extensive field use reveals the presence of a similar protective layer.

Bartley, L.S.; Fritz, P.O.; Pellet, R.J.; Taylor, S.A.; Van de Ven, P. [Texaco Fuels and Lubricants Technology Dept., Beacon, NY (United States)

1999-08-01

207

A computational study of icing effects on the performance of an S-duct inlet  

NASA Astrophysics Data System (ADS)

The performance of a diffusing S-duct inlet (M2129) is computationally studied for the effects of inlet icing. Different ice accretion shapes, predicted by numerical analysis in the literature reviewed, are simulated on the inlet lip. Two commercial codes, FLUENT and STAR-CCM+ are used for the steady- and unsteady-state computations. The shear-stress transport (SST) kappa-o turbulence model and large eddy simulation (LES) turbulence model are applied in the computations. The glaze ice shape, which is characterized by intrusive horns, degrades inlet performance, while the effect of the streamlined rime ice shape is negligible. At the free-stream Mach number of Minfinity =0.23, the glaze ice causes a 3.2 percent decrease in the total pressure recovery and a 26 percent reduction in the inlet mass flow rate. This result comes from the massive flow separation and flow blockage from the glaze ice horns. The total pressure recovery is further decreased by 22.8 percent, as the free-stream Mach number increases to Minfinity=0.85, due to the increased internal blockage and formation of internal shocks in the S-duct inlet. Also, the glaze iced inlet induces 6.6 percent increase in the engine thrust loss and the specific fuel consumption at Minfinity=0.25. The level of the ice-induced flow blockage by the ice accretion is also important for the inlet performance. The symmetrical glaze ice that covers the entire inlet lip portion causes a nearly 11.8 percent decrease in the total pressure recovery at Minfinity=0.475, whereas the top- or bottom-asymmetrical glaze ice that accretes on a portion of the inlet lip leads to just a 2.5 percent decrease. Also, the dynamic inlet distortion level, which is represented by the total pressure fluctuation at the engine face, is almost doubled with the symmetrical glaze ice when compared to the asymmetrical glaze ice. Therefore, the dynamic inlet distortion is proportional to the total pressure recovery that corresponds to the steady-state inlet distortion. Furthermore, the application of local angles of attack and local sideslip angles for the iced S-duct inlet contributes to the further degradation of the inlet performance, regardless of the ice shapes. However, the angles that provide the most distortion for each ice shape all differ due to the combined effects of the angle of attack or sideslip angle, icing location, and downward duct curvature. In addition, both the steady-state inlet distortion and dynamic inlet distortion become most severe at the highest angles tested: symmetrical (alpha=+20°), top-asymmetrical (alpha=-20°), bottom-asymmetrical (alpha=+20°), and side-asymmetrical glaze (beta=-20°). Finally, a strongly coupled temperature-total pressure distortion is created at the engine face under the icing condition. This coupling, as measured by the total pressure distortion parameter, increases the engine face distortion by 6.97 percent in the glaze iced inlet at Minfinity=0.85 when the inlet wall is heated to 350 K.

Jin, Wonjin

208

Boundary-Layer-Ingesting Inlet Flow Control  

NASA Technical Reports Server (NTRS)

An experimental study was conducted to provide the first demonstration of an active flow control system for a flush-mounted inlet with significant boundary-layer-ingestion in transonic flow conditions. The effectiveness of the flow control in reducing the circumferential distortion at the engine fan-face location was assessed using a 2.5%-scale model of a boundary-layer-ingesting offset diffusing inlet. The inlet was flush mounted to the tunnel wall and ingested a large boundary layer with a boundary-layer-to-inlet height ratio of 35%. Different jet distribution patterns and jet mass flow rates were used in the inlet to control distortion. A vane configuration was also tested. Finally a hybrid vane/jet configuration was tested leveraging strengths of both types of devices. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow rates through the duct and the flow control actuators. The distortion and pressure recovery were measured at the aerodynamic interface plane. The data show that control jets and vanes reduce circumferential distortion to acceptable levels. The point-design vane configuration produced higher distortion levels at off-design settings. The hybrid vane/jet flow control configuration reduced the off-design distortion levels to acceptable ones and used less than 0.5% of the inlet mass flow to supply the jets.

Owens, Lewis R.; Allan, Brian G.; Gorton, Susan A.

2008-01-01

209

Coolant passage heat transfer with rotation  

NASA Astrophysics Data System (ADS)

The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques and heat transfer correlations for rotating multipass coolant passages, with and without flow tabulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

Hajek, T. J.; Wagner, J. H.; Johnson, B. V.

1987-10-01

210

Coolant passage heat transfer with rotation  

NASA Astrophysics Data System (ADS)

The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

Hajek, T. J.; Higgins, A. W.

1985-10-01

211

Active Flow Control on an Aggressive Serpentine Duct Inlet  

Microsoft Academic Search

For military applications, inlet designs are constrained by low observability requirements, which call for the use of a serpentine inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the

John Vaccaro; Michael Amitay

2008-01-01

212

INLET CHANNEL, EGRESS OF BURIED CONDUIT SEGMENT TO PEN CHANNEL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

INLET CHANNEL, EGRESS OF BURIED CONDUIT SEGMENT TO PEN CHANNEL NEAR GATE TOWER, LOOKING WEST FORM LEFT BANK OF INLET CHANNEL. KACHESS RIVER CHANNEL (1910) TO REAR BEYOND INLET CHANNEL - Kachess Dam, Inlet Channel, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

213

Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors  

NASA Technical Reports Server (NTRS)

A model supersonic inlet with auxiliary inlet doors and boundary layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9 x 15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression. Previously announced in STAR as N83-27794

Woodward, R. P.; Glaser, F. W.; Lucas, J. G.

1983-01-01

214

Status of Physics and Safety Analyses for the Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR)  

SciTech Connect

A study has been completed to develop a new baseline core design for the liquid-salt-cooled very high-temperature reactor (LS-VHTR) that is better optimized for liquid coolant and that satisfies the top-level operational and safety targets, including strong passive safety performance, acceptable fuel cycle parameters, and favorable core reactivity response to coolant voiding. Three organizations participated in the study: Oak Ridge National Laboratory (ORNL), Idaho National Laboratory (INL), and Argonne National Laboratory (ANL). Although the intent was to generate a new reference LS-VHTR core design, the emphasis was on performing parametric studies of the many variables that constitute a design. The results of the parametric studies not only provide the basis for choosing the optimum balance of design options, they also provide a valuable understanding of the fundamental behavior of the core, which will be the basis of future design trade-off studies. A new 2400-MW(t) baseline design was established that consists of a cylindrical, nonannular core cooled by liquid {sup 7}Li{sub 2}BeF{sub 4} (Flibe) salt. The inlet and outlet coolant temperatures were decreased by 50 C, and the coolant channel diameter was increased to help lower the maximum fuel and vessel temperatures. An 18-month fuel cycle length with 156 GWD/t burnup was achieved with a two-batch shuffling scheme, while maintaining a core power density of 10 MW/m{sup 3} using graphite-coated uranium oxicarbide particle fuel enriched to 15% {sup 235}U and assuming a 25 vol-% packing of the coated particles in the fuel compacts. The revised design appears to have excellent steady-state and transient performance. The previous concern regarding the core's response to coolant voiding has been resolved for the case of Flibe coolant by increasing the coolant channel diameter and the fuel loading. Also, the LSVHTR has a strong decay heat removal performance and appears capable of surviving a loss of forced circulation (LOFC) even with failure to scram. Significant natural convection of the coolant salt occurs, resulting in fuel temperatures below steady-state values and nearly uniform temperature distributions during the transient.

Ingersoll, DT

2005-12-15

215

Inlet contour and flow effects on radiation  

NASA Astrophysics Data System (ADS)

An experimental investigation of sound radiation from inlets with different contours with and without flow is being conducted to study the possibility of reducing noise radiated by aircraft engines. For each inlet configuration, complex directivity patterns and complex pressure reflection coefficients are measured as a function of a single space-time structure of the wave (up to a frequency of 4000Hz and an azimuthal wave number 6) and of flow velocity (up to Mach number 0.4) in a cylindrical duct located downstream the inlet. Experimental results of radiation from an unflanged duct are compared with theory. Effect of inlet contour and flow are deduced by comparing respectively unflanged duct and bellmouth measurements and, no flow and flow measurements with the bellmouth. Results are presented which indicate that the contour effect is significant near the cut-on frequency of a mode and emphasize the necessity for taking into account the inlet geometry in a radiation prediction. These results show also that internal flow has a weak effect on the amplitude of the directivity pattern

Ville, J. M.; Silcox, R. J.

1980-06-01

216

Analysis of Buzz in a Supersonic Inlet  

NASA Technical Reports Server (NTRS)

A dual-stream, low-boom supersonic inlet designed for use on a small, Mach 1.6 aircraft was tested experimentally in the 8- by 6-Foot Supersonic Wind Tunnel (SWT) at the NASA Glenn Research Center (GRC). The tests showed that the inlet had good recovery and stable operation over large mass flow range. The inlet went into buzz at mass flows well below that needed for engine operation, and the experiments generated a wealth of data during buzz. High frequency response pressure measurements and high-speed schlieren videos were recorded for many buzz events. The objective of the present work was to use computational fluid dynamics (CFD) to predict some of the experimental data taken during buzz, compare those predictions to the experimental data, and to use both datasets to explain the physics of the buzz cycle. The calculations were done with the Wind-US CFD code using a second-order time-accurate differencing scheme and the SST turbulence model. Computed Mach number contours were compared with schlieren images, and ensemble-averaged unsteady pressures were compared to data. The results showed that the buzz cycle consisted partly of spike buzz, an unsteady oscillation of the main shock at the spike tip while the inlet pressure dropped, and partly of choked flow while the inlet repressurized. Most of the results could be explained by theory proposed by Dailey in 1954, but did not support commonly used acoustic resonance explanations.

Chima, Rodrick V.

2012-01-01

217

Characteristic parameters of superconductor-coolant interaction including high Tc current density limits  

NASA Technical Reports Server (NTRS)

In the area of basic mechanisms of helium heat transfer and related influence on super-conducting magnet stability, thermal boundary conditions are important constraints. Characteristic lengths are considered along with other parameters of the superconducting composite-coolant system. Based on helium temperature range developments, limiting critical current densities are assessed at low fields for high transition temperature superconductors.

Frederking, T. H. K.

1989-01-01

218

Thermal hydraulic characteristics during ingress of coolant and loss of vacuum events in fusion reactors  

Microsoft Academic Search

The thermal hydraulic characteristics in the vacuum vessel (VV) of a fusion reactor under an ingress of coolant event (ICE) and a loss of vacuum event (LOVA) were investigated quantitatively using preliminary experimental apparatuses. In the ICE experiments, pressure rise characteristics in the VV were clarified for experimental parameters of the wall temperature and water temperature and for cases with

K. Takase; T. Kunugi; Y. Seki; H. Akimoto

2000-01-01

219

Miniature piezo electric vacuum inlet valve  

DOEpatents

A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability is disclosed. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three. 6 figs.

Keville, R.F.; Dietrich, D.D.

1998-03-24

220

Miniature piezo electric vacuum inlet valve  

DOEpatents

A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

Keville, Robert F. (Valley Springs, CA); Dietrich, Daniel D. (Livermore, CA)

1998-03-24

221

Inlets for high angles of attack  

NASA Technical Reports Server (NTRS)

Different inlet designs for high angle of attack STOL and VTOL applications were tested in a subsonic wind tunnel. Three removable entry lips having contraction ratios of 1.30, 1.34 and 1.38 were tested with a single diffuser. The internal contour of each entry lip was an ellipse with a major to minor axis of 2.0. Each lip and diffuser assembly was tested to determine its tolerance to angle of attack, first with a conventional centerbody and then with an extended centerbody. Results indicate that a large improvement in separation angle (determined as a function of lip contraction ratio and inlet flow) was obtained for the extended centerbody for all contraction ratios. Improved inlet tolerance to angle of attack was obtained by reducing the adverse pressure gradient downstream of the throat.

Miller, B. A.

1976-01-01

222

Flow separation in inlets at incidence angles  

NASA Technical Reports Server (NTRS)

Wind-tunnel pressure data and flow pictures obtained for two two-dimensional inlet models have been examined to study the internal flow structure and separation at large incidence angles. The inlet models were 12-in. high (diffuser exit height) and had internal contraction ratio of 1.21 and 1.17. They were tested at low forward speeds over a wide range of throat Mach numbers (inlet mass flow rates) and angles of incidence. Characteristic features of the internal flow such as a drastic change of pressure gradient near the highlight, local separation bubbles and shock/boundary-layer interactions have been indicated and discussed. For a few specific cases, the experimental surface pressure distributions have been compared with theoretical predictions.

Jakubowski, A. K.; Luidens, R. W.

1981-01-01

223

Viscosity of alumina nanoparticles dispersed in car engine coolant  

SciTech Connect

The present paper, describes our experimental results on the viscosity of the nanofluid prepared by dispersing alumina nanoparticles (<50 nm) in commercial car coolant. The nanofluid prepared with calculated amount of oleic acid (surfactant) was tested to be stable for more than 80 days. The viscosity of the nanofluids is measured both as a function of alumina volume fraction and temperature between 10 and 50 C. While the pure base fluid display Newtonian behavior over the measured temperature, it transforms to a non-Newtonian fluid with addition of a small amount of alumina nanoparticles. Our results show that viscosity of the nanofluid increases with increasing nanoparticle concentration and decreases with increase in temperature. Most of the frequently used classical models severely under predict the measured viscosity. Volume fraction dependence of the nanofluid viscosity, however, is predicted fairly well on the basis of a recently reported theoretical model for nanofluids that takes into account the effect of Brownian motion of nanoparticles in the nanofluid. The temperature dependence of the viscosity of engine coolant based alumina nanofluids obeys the empirical correlation of the type: log ({mu}{sub nf}) = A exp(BT), proposed earlier by Namburu et al. (author)

Kole, Madhusree; Dey, T.K. [Thermophysical Measurements Laboratory, Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur 721 302 (India)

2010-09-15

224

Titanium Aluminide Scramjet Inlet Flap Subelement Benchmark Tested  

NASA Technical Reports Server (NTRS)

A subelement-level ultimate strength test was completed successfully at the NASA Glenn Research Center (http://www.nasa.gov/glenn/) on a large gamma titanium aluminide (TiAl) inlet flap demonstration piece. The test subjected the part to prototypical stress conditions by using unique fixtures that allowed both loading and support points to be located remote to the part itself (see the photograph). The resulting configuration produced shear, moment, and the consequent stress topology proportional to the design point. The test was conducted at room temperature, a harsh condition for the material because of reduced available ductility. Still, the peak experimental load-carrying capability exceeded original predictions.

Krause, David L.; Draper, Susan L.

2005-01-01

225

Mach 5 inlet CFD and experimental results  

NASA Technical Reports Server (NTRS)

An experimental research program was conducted in the NASA Lewis Research Center 10 x 10 ft supersonic wind tunnel. The 2-D inlet model was designed to study the Mach 3.0 to 5.0 speed range for an over-under turbojet plus ramjet propulsion system. The model was extensively instrumented to provide both analytical code validation data as well as inlet performance information. Support studies for the program include flow field predictions with both 3-D parabolized Navier-Stokes (PNS) and 3-D full Navier-Stokes (FNS) analytical codes. Analytical predictions and experimental results are compared.

Weir, Lois J.; Reddy, D. R.; Rupp, George D.

1989-01-01

226

Mach 5 inlet CFD and experimental results  

NASA Technical Reports Server (NTRS)

An experimental research program was conducted in the NASA Lewis Research Center 10 ft. by 10 ft. supersonic wind tunnel. The two-dimensional inlet model was designed to study the Mach 3.0 to 5.0 speed range for an 'over-under' turbojet plus ramjet propulsion system. The model was extensively instrumented to provide both analytical code validation data as well as inlet performance information. Support studies for the program include flow field predictions with both three-dimensional parabolized Navier-Stokes (PNS) and three-dimensional full Navier-Stokes (FNS) analytical codes. Analytical predictions and experimental results are compared.

Weir, Lois J.; Reddy, D. R.; Rupp, George D.

1989-01-01

227

Biases in ion transmission through an electrospray ionization – mass spectrometry capillary inlet  

PubMed Central

A heated capillary inlet for an electrospray ionization mass spectrometry (ESI-MS) interface was compared with shorter versions of the inlet to determine the effects on transmission and ionization efficiencies for low-flow (nano) electrosprays. Five different inlet lengths were studied, ranging from 6.4 to 1.3 cm. As expected, the electrospray current transmission efficiency increased with decreasing capillary length due to reduced losses to the inside walls of the capillary. This increase in transmission efficiency with shorter inlets was coupled with reduced desolvation of electrosprayed droplets. Surprisingly, as the inlet length was decreased, some analytes showed little or no increase in sensitivity, while others showed as much as a15 – fold gain. The variation was shown to beat least partially correlated with analyte mobilities, with the largest gains observed for higher mobility species, but also affected by solution conductivity, flow rate, and inlet temperature. Strategies for maximizing sensitivity while minimizing biases in ion transmission through the heated capillary interface are proposed. PMID:19815425

Page, Jason S.; Marginean, Ioan; Baker, Erin S.; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2010-01-01

228

Emergency cooling analysis for the loss of coolant malfunction  

NASA Technical Reports Server (NTRS)

This report examines the dynamic response of a conceptual space power fast-spectrum lithium cooled reactor to the loss of coolant malfunction and several emergency cooling concepts. The results show that, following the loss of primary coolant, the peak temperatures of the center most 73 fuel elements can range from 2556 K to the region of the fuel melting point of 3122 K within 3600 seconds after the start of the accident. Two types of emergency aftercooling concepts were examined: (1) full core open loop cooling and (2) partial core closed loop cooling. The full core open loop concept is a one pass method of supplying lithium to the 247 fuel pins. This method can maintain fuel temperature below the 1611 K transient damage limit but requires a sizable 22,680-kilogram auxiliary lithium supply. The second concept utilizes a redundant internal closed loop to supply lithium to only the central area of each hexagonal fuel array. By using this method and supplying lithium to only the triflute region, fuel temperatures can be held well below the transient damage limit.

Peoples, J. A.

1972-01-01

229

Icing Characteristics and Anti-Icing Heat Requirements for Hollow and Ternally Modified Gas-Heated Inlet Guide Vanes  

NASA Technical Reports Server (NTRS)

A two-dimensional inlet-guide-vane cascade was investigated to determine the effects of ice formations on the pressure losses across the guide vanes and to evaluate the heated gas flow and temperature required to prevent Icing at various conditions. A gas flow of approximately 0.4 percent of the inlet-air flow was necessary for anti-icing a hollow guide-vane stage at an inlet-gas temperature of 500 F under the following icing conditions: air velocity, 280 miles per hour; water content, 0.9 gram per cubic meter; and Inlet-air static temperature, 00 F. Also presented are the anti-icing gas flows required with modifications of the hollow Internal gas passage, which show heatinput savings greater than 50 percent.

Gray, Vernon H.; Bowden, Dean T.

1950-01-01

230

An implicit method for the calculation of inlet flow fields  

NASA Technical Reports Server (NTRS)

Inlet flow fields are calculated by an implicit, time marching procedure to solve the thin layer Navier-Stokes equations formulated in body fitted coordinates. Because the method can be used for a flow field with both subsonic and supersonic regions, it is applicable to subcritical as well as supercritical inlet operation. Results are presented and discussed for an inlet of current design practice. Results include inviscid calculations performed for supercritical inlet operation with uniform and nonuniform inflow boundary conditions as well as for subcritical inlet operation with uniform inflow boundary conditions. Results for viscous calculations performed for supercritical inlet operation with uniform inflow boundary conditions are also discussed.

Biringen, S.; Mcmillan, O. J.

1981-01-01

231

Numerical study of innovative scramjet inlets coupled to combustors using hydrocarbon-air mixture  

NASA Astrophysics Data System (ADS)

The research objective is to use high-fidelity multi-physics Computational Fluid Dynamics (CFD) analysis to characterize 3-D scramjet flowfields in two novel streamline traced circular configurations without axisymmetric profiles. This work builds on a body of research conducted over the past several years. In addition, this research provides the modeling and simulation support, prior to ground (wind tunnel) and flight experiment programs. Two innovative inlets, Jaws and Scoop, are analyzed and compared to a Baseline inlet, a current state of the art rectangular inlet used as a baseline for on/off-design conditions. The flight trajectory conditions selected were Mach 6 and a dynamic pressure of 1,500 psf (71.82 kPa), corresponding to a static pressure of 43.7 psf (2.09 kPa) and temperature of 400.8 R° (222.67 C°). All inlets are designed for equal flight conditions, equal contraction ratios and exit cross-sectional areas, thus facilitating their comparison and integration to a common combustor design. Analysis of these hypersonic inlets was performed to investigate distortion effects downstream in common generic combustors. These combustors include a single cavity acting as flame holder and strategically positioned fuel injection ports. This research not only seeks to identify the most successful integrated scramjet inlet/combustor design, but also investigates the flow physics and quantifies the integrated performance impact of the two novel scramjet inlet designs. It contributes to the hypersonic air-breathing community by providing analysis and predictions on directly-coupled combustor numerical experiments for developing pioneering inlets or nozzles for scramjets. Several validations and verifications of General Propulsion Analysis Chemical-kinetic and Two-phase (GPACT), the CFD tool, were conducted throughout the research. In addition, this study uses 13 gaseous species and 20 reactions for an Ethylene/air finite-rate chemical model. The key conclusions of this research are: (1) Flow distortion in the innovative inlets is similar to some of the distortion in the Baseline inlet, despite design differences. In both innovative inlets, the resulting flowfield distortions were due to shock boundary layer interactions similar to those found in the Baseline. The Baseline and Jaws performance attributes are stronger than Scoop, but Jaws accomplishes this while eradicating the cowl lip interaction, and lessening the total drag and spillage penalties. (2) The innovative inlets work best on-design, whereas for off-design, the traditional inlet yields a higher performance. Although the innovative inlets' designs mitigated some of the issues encountered in traditional configurations, they underperform at off-design conditions. The strategy used in Jaws was less prone to interaction with the near wall flow, and yields lesser pressure losses and higher efficiency at on-design conditions compared to the others. In general, the overall values for Scoop seem lowest of all due to lesser entrainment. Its drag coefficient and thrust to mass capture ratios are higher than the Baseline configuration. (3) Early pressure losses and flow distortions actually aid downstream combustion in all cases. Although interactions captured by the viscous simulations for the on-design conditions increase losses in the inlets, they enhance turbulence in the isolator, favoring the mixing of air and fuel, and improving the overall factor of the system. Jaws inlet demonstrates the most valuable design with higher performance, but its factor later in the combustor drops relative to its rectangular counterpart. (4) A parametric study of the location and direction of injection is conducted to select the configuration for fuel penetration, mixing factor (factor) and other combustion qualities. Although the trends observed with and without chemical reactions are the same, the former yields roughly 10% higher mixing factor. Unlike at frozen conditions, when chemical reactions are considered, a high compression area was observed upstream of the cavity, not presen

Malo-Molina, Faure Joel

232

Experimental investigation of a submerged subsonic inlet  

Microsoft Academic Search

The goal of combined computational and experimental study is the design optimization of a generic submerged inlet, which minimizes flow distortion at the engine face. A series of experimental surveys were performed to validate the accompanying computations and to provide additional information regarding the Pareto Set of optimal designs. The objectives of experimental investigation are to: (1) perform comparison between

Vasilije J. Jovanovic

2004-01-01

233

Inlet distortion effects in axial compressors  

Microsoft Academic Search

Methods for predicting compressor response to inlet distortion are discussed. The emphasis is on those approaches which have proved most useful in analyzing circumferentially nonuniform flows in multistage compressors (as opposed to isolated rotors or single stages). Attention is focussed on the basic fluid mechanic concepts which underlie these methods in order to develop a clear physical understanding of the

E. M. Greitzer

1979-01-01

234

Muir Glacier and Muir Inlet 1980  

USGS Multimedia Gallery

This ship-deck-based August 1980 photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, shows the nearly 200-ft-high retreating tidewater end of Muir Glacier with part of its face capped by a few angular pinnacles of ice, called séracs....

235

Design and operation considerations for attic inlets  

Technology Transfer Automated Retrieval System (TEKTRAN)

Improving energy efficiency and environmental control in poultry facilities is essential for profitability. Increases in energy costs have prompted evaluation of solar energy systems and passive solar systems such as attic inlets have been adopted as a means to reduce fuel usage. Successful implem...

236

AEROSOL SAMPLING INLETS AND INHALABLE PARTICLES  

EPA Science Inventory

The problem of sampling aerosols from the ambient atmosphere has been considered from a theoretical point of view. Following a review of the various samplers and inlets used in ambient sampling, the factors contributing to high sampling efficiency for large particles are discusse...

237

Cloud-Droplet Ingestion in Engine Inlets with Inlet Velocity Ratios of 1.0 and 0.7  

NASA Technical Reports Server (NTRS)

The paths of cloud droplets into two engine inlets have been calculated for a wide range of meteorological and flight conditions. The amount of water in droplet form ingested by the inlets and the amount and distribution of water impinging on the inlet walls are obtained from these droplet-trajectory calculations. In both types of inlet, a prolate ellipsoid of revolution represents either part or all of the forebody at the center of an annular inlet to an engine. The configurations can also represent a fuselage of an airplane with side ram-scoop inlets. The studies were made at an angle of attack of 0 degree. The principal difference between the two inlets studied is that the inlet-air velocity of one is 0.7 that of the other. The studies of the two velocity ratios lead to some important general concepts of water ingestion in inlets.

Brun, Rinaldo J

1957-01-01

238

On-Line Coolant Chemistry Analysis  

SciTech Connect

Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.

LM Bachman

2006-07-19

239

Application of analytical capability to predict rapid cladding cooling and quench during the blowdown phase of a large break loss-of-coolant accident. [PWR  

Microsoft Academic Search

Large-break Experiments L2-2 and L2-3 conducted in the Loss-of-Fluid Test (LOFT) facility experienced core-wide rapid quenches early in the blowdown transients. To further investigate rapid cladding quenches, separate effects experiments using Semiscale solid-type electric heater rods were conducted in the LOFT Test Support Facility (LTSF) over a wide range of inlet coolant conditions. The analytical capability to predict the cladding

S. N. Aksan; E. L. Tolman; R. A. Nelson

1983-01-01

240

Inlet-engine matching for SCAR including application of a bicone variable geometry inlet  

NASA Technical Reports Server (NTRS)

Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined, where the second cone of a two cone center body collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

Wasserbauer, J. F.; Gerstenmaier, W. H.

1978-01-01

241

A Parametric Study of a Large Break in Reactor Inlet Header of CANDU6 Reactors Using RELAP5 Code  

SciTech Connect

A large break loss of coolant accident in a CANDU can lead to degraded fuel cooling in a large number of fuel channels due to the apparition of a prolonged flow stagnation period in the downstream core pass. The paper presents a parametric study of a reactor inlet header break. The parametric survey includes: the size of the break, the choked flow model employed, the emergency core cooling (ECC) performance and the core nodalization. The study is performed with RELAP5/SCDAP mod 3.4 and the results are compared with the safety analysis results. (authors)

Prisecaru, Ilie; Dupleac, Daniel; Ghitescu, Petre [Power Plant Engineering Faculty, Politehnica Univ., 313 Splaiul Independentei, Bucharest (Romania); Biro, Lucian [National Commission for Nuclear Activities Control, 14 Libertatii Blvd., Bucharest (Romania)

2006-07-01

242

Geometry of tidal inlet systems: A key factor for the net sediment transport in tidal inlets  

NASA Astrophysics Data System (ADS)

net transport of sediment between the back-barrier basin and the sea is an important process for determining the stability of tidal inlet systems. Earlier studies showed that in a short basin, tidal flats favor peak ebb-currents stronger than peak flood currents, implying export of coarse sediment, while shallow basins favor stronger flood currents. The new elements considered in this study are (1) arbitrary basin lengths, (2) a narrow inlet that connects the basin to the sea, (3) an asymmetric tidal forcing, and (4) radiation damping. The objective is to gain fundamental insight in how the geometry of a tidal inlet system affects the net sand transport in a tidal inlet. For this purpose, a width-averaged and depth-averaged analytical model was constructed. It is found that the length of a back-barrier basin controls the effect that nonlinear hydrodynamic processes have on the tidal asymmetry, and consequently controls whether the currents in the inlet are flood-dominant or ebb-dominant. Furthermore, the cross-sectional area of the inlet controls the ratio between the net sediment transports that results from tidal asymmetry and that caused by the interaction of the principal tide with the residual current. Finally, it is shown that the effect of an asymmetric tidal forcing on the net sand transport depends on the length of the back-barrier basin with respect to the tidal wavelength in that basin.

Ridderinkhof, W.; de Swart, H. E.; van der Vegt, M.; Alebregtse, N. C.; Hoekstra, P.

2014-10-01

243

Experimentally determined aeroacoustic performance and control of several sonic inlets  

NASA Technical Reports Server (NTRS)

Low speed wind tunnel tests were conducted to determine the aeroacoustic performance of several model sonic inlets. The results were analyzed to indicate how inlet aeroacoustic characteristics were affected by inlet design and operating conditions. A system for regulating sonic inlet noise reduction was developed and tested. Results indicate that pressure losses at forward velocity may be substantially less than those at static conditions. This is particularly true for translating centerbody inlets with the centerbody extended in the approach and landing position. Operation to simulated takeoff incidence angles of 50 degrees was demonstrated with good inlet performance. Inlet sound pressure level reduction was regulation was regulated to within approximately + or - 1 dB by controlling inlet surface static pressure measured at the diffuser exit.

Miller, B. A.

1975-01-01

244

NGNP Reactor Coolant Chemistry Control Study  

SciTech Connect

The main focus of this paper is to identify the most desirable ranges of impurity levels in the primary coolant to optimize component life in the primary circuit of the Next Generation Nuclear Plant (NGNP), which will either be a prismatic block or pebble bed reactor.

Brian Castle

2010-11-01

245

Welds chilled by liquid coolant manifold  

NASA Technical Reports Server (NTRS)

Liquid coolant chill tool provides uniform cooling to materials adjacent to weld areas on long or contoured butt welds. This tool incorporates a manifold that clamps to the weld joint by vacuum and circulates liquid in direct contact with adjacent material.

Odor, M. E.; Whiffen, E. E.

1966-01-01

246

Experimental interaction of magma and “dirty” coolants  

NASA Astrophysics Data System (ADS)

The presence of water at volcanic vents can have dramatic effects on fragmentation and eruption dynamics, but little is known about how the presence of particulate matter in external water will further alter eruptions. Volcanic edifices are inherently “dirty” places, where particulate matter of multiple origins and grainsizes typically abounds. We present the results of experiments designed to simulate non-explosive interactions between molten basalt and various “coolants,” ranging from homogeneous suspensions of 0 to 30 mass% bentonite clay in pure water, to heterogeneous and/or stratified suspensions including bentonite, sand, synthetic glass beads and/or naturally-sorted pumice. Four types of data are used to characterise the interactions: (1) visual/video observations; (2) grainsize and morphology of resulting particles; (3) heat-transfer data from a network of eight thermocouples; and (4) acoustic data from three force sensors. In homogeneous coolants with <~10% bentonite, heat transfer is by convection, and the melt is efficiently fragmented into blocky particles through multiple thermal granulation events which produce associated acoustic signals. For all coolants with >~20% sediment, heat transfer is by forced convection and conduction, and thermal granulation is less efficient, resulting in fewer blocky particles, larger grainsizes, and weaker acoustic signals. Many particles are droplet-shaped or/and “vesicular,” containing bubbles filled with coolant. Both of these particle types indicate significant hydrodynamic magma-coolant mingling, and many of them are rewelded into compound particles. The addition of coarse material to heterogeneous suspensions further slows heat transfer thus reducing thermal granulation, and variable interlocking of large particles prevents efficient hydrodynamic mingling. This results primarily in rewelded melt piles and inefficient distribution of melt and heat throughout the coolant volume. Our results indicate that even modest concentrations of sediment in water will significantly limit heat transfer during non-explosive magma-water interactions. At high concentrations, the dramatic reduction in cooling efficiency and increase in mingling help to explain globular peperite, and provide information relevant to analyses of premixing associated with highly-explosive molten fuel-coolant interactions in debris-filled volcanic vents.

Schipper, C. Ian; White, James D. L.; Zimanowski, Bernd; Büttner, Ralf; Sonder, Ingo; Schmid, Andrea

2011-03-01

247

Flow Control in a Compact Inlet  

NASA Astrophysics Data System (ADS)

An experimental investigation of flow control, via various control jets actuators, was undertaken to eliminate separation and secondary flows in a compact inlet. The compact inlet studied was highly aggressive with a length-to-diameter ratio of 1.5. A brand new facility was designed and built to enable various actuation methodologies as well as multiple measurement techniques. Techniques included static surface pressure, total pressure, and stereoscopic particle image velocimetry. Experimental data were supplemented with numerical simulations courtesy of Prof. Kenneth Jansen, Dr. Onkar Sahni, and Yi Chen. The baseline flow field was found to be dominated by two massive separations and secondary flow structures. These secondary structures were present at the aerodynamic interface plane in the form of two counter-rotating vortices inducing upwash along centerline. A dominant shedding frequency of 350 Hz was measured both at the aerodynamic interface plane and along the lower surface of the inlet. Flow control experiments started utilizing a pair of control jets placed in streamwise locations where flow was found to separate. Tests were performed for a range of inlet Mach numbers from 0.2 to 0.44. Steady and unsteady static pressure measurements along the upper and lower walls of the duct were performed for various combinations of actuation. The parameters that were tested include the control jets momentum coefficient, their blowing ratio, the actuation frequency, as well as different combinations of jets. It was shown that using mass flux ratio as a criterion to define flow control is not sufficient, and one needs to provide both the momentum coefficient and the blowing ratio to quantify the flow control performance. A detailed study was undertaken on controlling the upstream separation point for an inlet Mach number of 0.44. Similar to the baseline flow field, the flow field associated with the activation of a two-dimensional control jet actuator was dominated by secondary flow structures. Unlike the baseline, these secondary flow structures produced downwash along the centerline. The formation of such structures was caused by the core flow stagnating on the lower surface near the aerodynamic interface plane. Using the two-dimensional steady jet resulted in an increase in the spanwise flow within the inlet and a reduction in the energy content of the 350 Hz shedding frequency. Unsteady forcing did not show much improvement over steady forcing for this configuration. A spanwise varying control jet and a hybrid Coanda jet / vortex generator jets were tested to reduce the three-dimensionality of the flow field. It was found that anytime the flow control method suppressed separation along the centerline, counter-rotating vortices existed in the lower corners of the aerodynamic interface plane.

Vaccaro, John C.

2011-12-01

248

Numerical Investigation of Actuators for Flow Control in Inlet Ducts  

Microsoft Academic Search

For military applications, inlet designs are constrained by low observability requirements, which call for the use of an S-duct inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the

Kenneth Jansen; Onkar Sahni; Michael Amitay

2009-01-01

249

Experimental Investigation of Actuators for Flow Control in Inlet Ducts  

Microsoft Academic Search

For military applications, inlet designs are constrained by low observability requirements, which call for the use of an S-duct inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the

John Vaccaro; Michael Amitay

2009-01-01

250

6. View southwest, culvert inlet with canal bank completely removed. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. View southwest, culvert inlet with canal bank completely removed. Left to right: back of headwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall along former edge of canal bank; dewatered canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

251

Low speed performance of a supersonic axisymmetric mixed compression inlet with auxiliary inlets. [Lewis 9x15-ft anechoic wind tunnel tests  

NASA Technical Reports Server (NTRS)

The aerodynamic performance of a representative supersonic cruise inlet was investigated using a fan simulator coupled to the inlet to provide characteristic noise signatures and to pump the inlet flow. Data were obtained at Mach numbers from 0 to 0.2 for the inlet equipped with an auxiliary inlet system that provided 20 to 40 percent of the fan flow. Results show that inlet performance improved when the inlet bleed systems were sealed; when the freestream Mach number was increased; and when the auxiliary inlets were opened. The inlet flow could not be choked by either centerbody translation or by increasing the fan speed when the 40 percent auxiliary inlet was incorporated.

Wasserbauer, J. F.; Cubbison, R. W.; Trefny, C. J.

1983-01-01

252

ACTIVE CONTROL OF INTEGRATED INLET \\/ COMPRESSION SYSTEMS: INITIAL RESULTS  

Microsoft Academic Search

Substantial reductions in aircraft size are possible if shorter, more aggressive, serpentine inlet ducts are used for low- observability constrained propulsion installations. To ob- tain this benet, both inlet separation and compressor stall dynamics must be controlled. In this paper the integrated control of this coupled inlet\\/compression system is consid- ered. Initial results are shown using separation point actu- ation

Douglas G. MacMartin; Ashish Verma; Richard M. Murray; James D. Paduano

2001-01-01

253

ACTIVE FLOW CONTROL OF INLET DUCTS Sponsor: Northrop Grumman  

E-print Network

in distortion and total pressure loss at the inlet exit, which is clearly undesirable. The present researchACTIVE FLOW CONTROL OF INLET DUCTS Sponsor: Northrop Grumman Funding: $225,000 for 1 year (started Undergraduate students: Brian Belley, Wasif Khan PROJECT DESCRIPTION The inlet to an aircraft propulsion system

Salama, Khaled

254

40 CFR 89.328 - Inlet and exhaust restrictions.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Inlet and exhaust restrictions...PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...Provisions § 89.328 Inlet and exhaust restrictions...system presenting an air inlet restriction within 5 percent...upper limit at maximum air flow, as specified by...

2010-07-01

255

40 CFR 89.328 - Inlet and exhaust restrictions.  

Code of Federal Regulations, 2014 CFR

...2013-07-01 true Inlet and exhaust restrictions...PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...Provisions § 89.328 Inlet and exhaust restrictions...system presenting an air inlet restriction within 5 percent...upper limit at maximum air flow, as specified by...

2014-07-01

256

Flow-Control Devices For Inlets Of Indraft Wind Tunnels  

NASA Technical Reports Server (NTRS)

Report presents theoretical and experimental study of effects of antiturbulence flow-control devices in inlet of indraft wind tunnel upon nonuniformity of flow in test section of tunnel. Flow-control devices in question include vanes, screens, and honeycombs, placed in inlet upstream of contracting section of tunnel leading from inlet to test section.

Ross, James C.

1992-01-01

257

40 CFR 89.328 - Inlet and exhaust restrictions.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Inlet and exhaust restrictions...PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...Provisions § 89.328 Inlet and exhaust restrictions...system presenting an air inlet restriction within 5 percent...upper limit at maximum air flow, as specified by...

2012-07-01

258

40 CFR 89.328 - Inlet and exhaust restrictions.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Inlet and exhaust restrictions...PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...Provisions § 89.328 Inlet and exhaust restrictions...system presenting an air inlet restriction within 5 percent...upper limit at maximum air flow, as specified by...

2011-07-01

259

40 CFR 89.328 - Inlet and exhaust restrictions.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Inlet and exhaust restrictions...PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW...Provisions § 89.328 Inlet and exhaust restrictions...system presenting an air inlet restriction within 5 percent...upper limit at maximum air flow, as specified by...

2013-07-01

260

OPEN SEGMENT OF INLET CHANNEL, KACHESS RESERVOIR TO REAR, FROM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OPEN SEGMENT OF INLET CHANNEL, KACHESS RESERVOIR TO REAR, FROM BERM OVER START OF BURIED CONDUIT SEGMENT OF INLET CHANNEL (6/96), LOOKING NORTHEAST - Kachess Dam, Inlet Channel, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

261

The effect of fuel thermal conductivity on the behavior of LWR cores during loss-of-coolant accidents  

NASA Astrophysics Data System (ADS)

The effect of variation in thermal conductivity of light water reactor fuel elements on core response during loss-of-coolant accident scenarios is examined. Initially, a simplified numerical analysis is utilized to determine the time scales associated with dissipation of stored energy from the fuel into the coolant once the fission reaction is stopped. The analysis is then followed by full reactor system thermal-hydraulics analysis of a typical boiling and pressurized water reactor subjected to a large break loss-of-coolant accident scenario using the TRACE code. Accordingly, sensitivity analyses to examine the effect of an increase in fuel thermal conductivity, up to 500%, on fuel temperature evolution during these transients are performed. Given the major differences in thermal-hydraulics design aspects of boiling and pressurized water reactors, different fuel and temperature responses during the simulated loss-of-coolant transients are observed.

Terrani, Kurt A.; Wang, Dean; Ott, Larry J.; Montgomery, Robert O.

2014-05-01

262

Application of analytical capability to predict rapid cladding cooling and quench during the blowdown phase of a large break loss-of-coolant accident. [PWR  

SciTech Connect

Large-break Experiments L2-2 and L2-3 conducted in the Loss-of-Fluid Test (LOFT) facility experienced core-wide rapid quenches early in the blowdown transients. To further investigate rapid cladding quenches, separate effects experiments using Semiscale solid-type electric heater rods were conducted in the LOFT Test Support Facility (LTSF) over a wide range of inlet coolant conditions. The analytical capability to predict the cladding temperature response from selected LTSF experiments estimated to bound the hydraulic conditions causing the LOFT early blowdown quenches was investigated using the RELAP4 computer code and was shown to be acceptable over the film boiling cooldown phase. This analytical capability was then used to investigate the behavior of nuclear fuel rods under the same hydraulic conditions. The calculations show that, under rapid cooling conditions, the behaviors of nuclear and electrical heater rods are significantly different because the nuclear rods are conduction limited, while the electrical rods are convection limited.

Aksan, S.N.; Tolman, E.L.; Nelson, R.A.

1983-01-01

263

Design Study Of The HTTR With Lead - Bismuth Coolant Use Uranium And Thorium Fuel  

Microsoft Academic Search

DESIGN STUDY OF THE HTTR WITH LEAD - BISMUTH COOLANT USE URANIUM AND THORIUM FUEL. The High Temperature Engineering Test Reactor (HTTR) is the type of High Temperature Gas-cooled Reactor (HTGR) which use low-enriched uranium. As a test reactor owning special safety characteristics, HTTR has designed with thermal output of 30 MW, outlet temperature of 950 oC and the maximum

Deby Mardiansah; Ratu Fenny Muldiani

264

Optimal Design of a Subsonic Submerged Inlet  

NASA Astrophysics Data System (ADS)

A multi-objective optimization study based on an epsilon-constraint method is conducted for the design optimization of a subsonic submerged air vehicle inlet. The multi-objective optimization problem is reformulated by minimizing one of the objectives and restricting the other objectives within user specified values. The figures of merits are the engine-face distortion and swirl that determines the inlet/engine compatibility. The distortion index is minimized while the feasible design space is determined by the swirl index. The design variables are the geometrical parameters defining the surface alteration. The design algorithm is driven by a gradient-based optimizer, and is constructed by integrating the optimizer with a solid modeller (Pro/Engineer), a mesh generator (Grid/Pro) and a flow solver (GASPex). The optimizer is CFSQP (C code for Feasible Sequential Quadratic Programming). Integration of the software packages is achieved by a Perl script. In order to verify the numerical results, an experimental setup for the same inlet geometry is prepared to run at the same flow conditions. The presentation will describe the numerical approach and summarize the results.

Taskinoglu, Ezgi; Jovanovic, Vasilije; Elliott, Gregory; Knight, Doyle

2003-11-01

265

A comparative assessment of alternative combustion turbine inlet air cooling system  

SciTech Connect

Interest in combustion turbine inlet air cooling (CTAC) has increased during the last few years as electric utilities face increasing demand for peak power. Inlet air cooling increases the generating capacity and decreases the heat rate of a combustion turbine during hot weather when the demand for electricity is generally the greatest. Several CTAC systems have been installed, but the general applicability of the concept and the preference for specific concepts is still being debated. Concurrently, Rocky Research of Boulder City, Nevada has been funded by the U.S. Department of Energy to conduct research on complex compound (ammoniated salt) chiller systems for low-temperature refrigeration applications.

Brown, D.R.; Katipamula, S.; Konynenbelt, J.H.

1996-02-01

266

Inlet Turbulence and Length Scale Measurements in a Large Scale Transonic Turbine Cascade  

NASA Technical Reports Server (NTRS)

Constant temperature hotwire anemometry data were acquired to determine the inlet turbulence conditions of a transonic turbine blade linear cascade. Flow conditions and angles were investigated that corresponded to the take-off and cruise conditions of the Variable Speed Power Turbine (VSPT) project and to an Energy Efficient Engine (EEE) scaled rotor blade tip section. Mean and turbulent flowfield measurements including intensity, length scale, turbulence decay, and power spectra were determined for high and low turbulence intensity flows at various Reynolds numbers and spanwise locations. The experimental data will be useful for establishing the inlet boundary conditions needed to validate turbulence models in CFD codes.

Thurman, Douglas; Flegel, Ashlie; Giel, Paul

2014-01-01

267

An analysis of heat transfer after loss of primary coolant in the SP100 reactor system  

Microsoft Academic Search

This study determines design guidelines for the SP-100 space reactor core cooling system after a loss of coolant accident. The Thermal Systems Analysis Code (TSAP) calculated the temperatures within the fuel assemblies as a result of the fuel decay heat. TSAP is a lumped-parameter network analysis code capable of performing radiative and conductive heat transfer analysis. The reactor core was

Donald W. Robbins

1988-01-01

268

Effect of Microstructure on Failure Behavior of Light Water Reactor Coolant Piping under Severe Accident Conditions  

Microsoft Academic Search

In a severe accident of light water reactors, the reactor coolant system (RCS) piping might be subjected to thermal loads caused by the decay heat of the deposited fission products and the heat transfer from the hot gases, with an internal pressure in some accident sequences. Tests on the RCS piping failure were performed along with high temperature tensile and

Yuhei HARADA; Yu MARUYAMA; Akio MAEDA; Hiroaki SHIBAZAKI; Tamotsu KUDO; Akihide HIDAKA; Kazuichiro HASHIMOTO; Jun SUGIMOTO

1999-01-01

269

Experiments and analysis, by the method of characteristics, on loss of coolant accidents  

Microsoft Academic Search

An outline of a technique for analysis of LOCAs by the method of ; characteristics and some comparisons with experiments are presented. Prediction ; of coolant density in the heated section, pressures, temperatures, and flow rates ; as functions of time following a pipe rupture are discussed. (GE) The Spanish ; Atomic Forum dedicated the 1972 lectures to the problem

S. Banerjee; R. B. Jeffries; H. Goulding; T. Jaganathan

1973-01-01

270

Loss-of-coolant accident experiment at the AVR gas-cooled reactor  

SciTech Connect

Loss-of-coolant is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into small High-Temperature Gas Cooled Reactor (HTGR) designs, loss-of-coolant accident (LOCA) simulation tests have been conducted with the German pebble-bed High-Temperature Reactor AVR. The AVR is the only nuclear power plant ever to have been intentionally subjected to LOCA conditions. The LOCA test was planned to create conditions that would exist if a rapid LOCA occurred with the reactor operating at full power. The tests demonstrated this reactor's safe response to an accident in which the coolant escapes from the reactor core and no emergency system is available to provide coolant flow to the core. The test is of special interest because it demonstrates the inherent safety features incorporated into modular HTGR designs. The main LOCA test lasted for 5 d. After the test began, core temperatures increased for {approximately}13 h and then gradually and continually decreased as the rate of heat dissipation from the core exceeded accident levels of decay power. Throughout the test, temperatures remained below limiting values for the core and other reactor components. 3 refs., 9 figs., 1 tab.

Cleveland, J.; Krueger, K. (Oak Ridge National Lab., TN (USA); Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Arbeitsgemeinschaft Versuchsreaktor)

1989-01-01

271

Flow in the coolant passages of an internal combustion engine cylinder head  

Microsoft Academic Search

Detailed measurements of the coolant flow field have been made in the water passages of the cylinder head of an internal combustion engine. They were obtained by casting a transparent acrylic model of the cylinder head and using a mixture of hydrocarbon fluids at a predetermined temperature and concentration which ensured that the refractive index of the fluid was identical

C. H. Liu; C. Vafidis; J. H. Whitelaw; R. Margary

1990-01-01

272

HOTROD: a computer program for subchannel analysis of coolant flow in rod bundles  

Microsoft Academic Search

A digital computer program is described for the steady-state thermal and ; hydraulic subchannel analysis of coolant flow in rod bundle reactor cores and ; heated-rod experimental test sections. The program allows for the transfer of ; two-phase fluid properties in three dimensions and predicts the local fluid ; conditions, fuel rod surface temperature and critical heat flux. The history

S. G. Beus; J. H. Anderson; R. J. DeCristofaro

1973-01-01

273

Some flow phenomena associated with aligned, sequential apertures with Borda-type inlets. [inlet pressure and flow separation  

NASA Technical Reports Server (NTRS)

Choked flow rate and pressure profile data were taken and studied for a configuration consisting of four axially aligned, sequential Borda tubes of 1.9 length diameter ratio with separation distances of 0.8 and 30 tube diameters. For either case the flow rate data could be represented by a flow coefficient reduced temperature plot. At a separation distance of 30 tube diameters the pressure profiles dropped sharply at the entrance and recovered within each Borda tube; except at low temperatures, where fluid jetting through the last Borda tube occurred. At a separation distance of 0.8 tube jetting was prevalent, and application of a significant backpressure did not alter the jetting. These results agree with other data for tubes with Borda or sharp edge orifice inlets and with a water flow visualization study reported herein.

Hendericks, R. C.; Stetz, T. T.

1981-01-01

274

Loss-of-coolant accident experiment at the AVR (Arbeitsgemeinschaft Versuchsreaktor) gas-cooled reactor  

SciTech Connect

Loss of coolant is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into modular gas-cooled reactor designs, loss-of-coolant accident (LOCA) simulation tests were conducted with the 15-MW(electric), 46-MW(thermal), pebble-bed, high-temperature Arbeitsgemeinschaft Versuchsreaktor (AVR) in the Federal Republic of Germany (FRG). This is the only nuclear power plant ever to have been intentionally subjected to LOCa conditions. Oak Ridge National Laboratory participation in the preparation and conduct of the tests was carried out within the U.S./FRG Agreement for Cooperation in Gas-Cooled Reactor Development.

Krueger, K. (Arbeitsgemeinschaft Versuchsreaktor, Juelich (West Germany)); Cleveland, J. (Oak Ridge National Laboratory, TN (USA))

1989-11-01

275

7. View north at back (canal side) of culvert inlet, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View north at back (canal side) of culvert inlet, with canal bank completely removed. Background to foreground: back of inlet headwall with tops of high inlet barrels exposed; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall at site of former canal edge of canal bank; dewatered canal bed and plank sheathing on top of culvert barrels beneath canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

276

Numerical Study on the Local Temperature in IRWST Pool  

Microsoft Academic Search

The Safety Depressurization Vent System (SDVS) of APR 1400 prevents Reactor Coolant System (RCS) from over-pressurization by discharging high pressure and temperature coolant through the I-sparger into the IRWST during an accident. If IRWST water temperature rises locally, around the sparger, beyond 200 deg. by the discharged coolant, unstable steam condensation may occur and cause large pressure load on the

H. S. Kang; Y. Y. Bae; J. K. Park

2002-01-01

277

Effect of steady-state pressure distortion on inlet flow to a high-bypass-ratio turbofan engine  

NASA Technical Reports Server (NTRS)

Static pressure and total pressure distributions were measured in the inlet duct upstream of the engine inlet and within the fan and compressor of a YTF34 turbofan engine. In addition, the free stream flow angle was measured between the distortion generator and the engine inlet. Distortions were generated using three screen configurations with extents of 90 deg or 180 deg. The screens were mounted on a rotatable screen assembly. Reynolds number index upstream of the distortion device was maintained at 0.5 or 0.2, and engine fan speed corrected to station 2 temperature was maintained at 80 or 90 percent of rated condition (7005 rpm). Flow angle was nearly constant near the distortion device and increased as flow approached the engine inlet. The largest flow angle occurred in the hub region of the engine inlet. Static pressure distortion along the inlet duct increased exponentially as the flow approached the engine. Both static pressure and total pressure distortions were attenuated between engine inlet and compressor exit.

Soeder, R. H.; Bobula, G. A.

1982-01-01

278

First principles calculations predict stable 50 nm nickel ferrite particles in PWR coolant  

NASA Astrophysics Data System (ADS)

Thermodynamic calculations that combine experimental data with the results of first principles calculations yield negative free energies for {1 1 1} surfaces of nickel ferrite for the temperature, pressure and ion concentrations typical of Pressurized Light Water Reactor (PWR) coolant. When combined with a positive bulk free energy of formation, the negative surface energies predict that thermodynamically-stable octahedral nickel ferrite particles with diameters of ?50 nm should be present in PWR coolant during operation. These particles would not be removed by mixed bed demineralizers and would be below the filter pore sizes typically used in Chemical and Volume Control Systems. The calculations also predict that these particles are not thermodynamically stable in coolant under ambient conditions. Based on these results it is proposed that solvated nickel ferrite particles, which are predicted to be stable and likely long-lived in PWR primary coolant, contribute to the nucleation of metal oxide scale on PWR fuel rod cladding and that conventional methods for purifying the primary coolant may be ineffective in removing these species.

O'Brien, C. J.; Rák, Zs.; Bucholz, E. W.; Brenner, D. W.

2014-11-01

279

A new approach for the design of hypersonic scramjet inlets  

NASA Astrophysics Data System (ADS)

A new methodology has been developed for the design of hypersonic scramjet inlets using gas dynamic relations. The approach aims to find the optimal inlet geometry which has maximum total pressure recovery at a prescribed design free stream Mach number. The design criteria for inlet is chosen as shock-on-lip condition which ensures maximum capture area and minimum intake length. Designed inlet geometries are simulated using computational fluid dynamics analysis. The effects of 1D, 2D inviscid and viscous effects on performance of scramjet inlet are reported here. A correction factor in inviscid design is reported for viscous effects to obtain shock-on-lip condition. A parametric study is carried out for the effect of Mach number at the beginning of isolator for the design of scramjet inlets. Present results show that 2D and viscous effects are significant on performance of scramjet inlet. Present simulation results are matching very well with the experimental results available from the literature.

Raj, N. Om Prakash; Venkatasubbaiah, K.

2012-08-01

280

Investigating Liquid CO2 as a Coolant for a MTSA Heat Exchanger Design  

NASA Technical Reports Server (NTRS)

Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO 2) control for a future Portable Life Support System (PLSS), as well as water recycling. CO 2 removal and rejection is accomplished by driving a sorbent through a temperature swing of approximately 210 K to 280 K . The sorbent is cooled to these sub-freezing temperatures by a Sublimating Heat Exchanger (SHX) with liquid coolant expanded to sublimation temperatures. Water is the baseline coolant available on the moon, and if used, provides a competitive solution to the current baseline PLSS schematic. Liquid CO2 (LCO2) is another non-cryogenic coolant readily available from Martian resources which can be produced and stored using relatively low power and minimal infrastructure. LCO 2 expands from high pressure liquid (5800 kPa) to Mars ambient (0.8 kPa) to produce a gas / solid mixture at temperatures as low as 156 K. Analysis and experimental work are presented to investigate factors that drive the design of a heat exchanger to effectively use this sink. Emphasis is given to enabling efficient use of the CO 2 cooling potential and mitigation of heat exchanger clogging due to solid formation. Minimizing mass and size as well as coolant delivery are also considered. The analysis and experimental work is specifically performed in an MTSA-like application to enable higher fidelity modeling for future optimization of a SHX design. In doing so, the work also demonstrates principles and concepts so that the design can be further optimized later in integrated applications (including Lunar application where water might be a choice of coolant).

Paul, Heather L.; Padilla, Sebastian; Powers, Aaron; Iacomini, Christie

2009-01-01

281

Advanced Technology Inlet Design, NRA 8-21 Cycle II: DRACO Flowpath Hypersonic Inlet Design  

NASA Technical Reports Server (NTRS)

The report outlines work performed in support of the flowpath development for the DRACO engine program. The design process initiated to develop a hypersonic axisymmetric inlet for a Mach 6 rocket-based combined cycle (RBCC) engine is discussed. Various design parametrics were investigated, including design shock-on-lip Mach number, cone angle, throat Mach number, throat angle. length of distributed compression, and subsonic diffuser contours. Conceptual mechanical designs consistent with installation into the D-21 vehicle were developed. Additionally, program planning for an intensive inlet development program to support a Critical Design Review in three years was performed. This development program included both analytical and experimental elements and support for a flight-capable inlet mechanical design.

Sanders, Bobby W.; Weir, Lois J.

1999-01-01

282

Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident  

SciTech Connect

Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

Su'ud, Zaki; Anshari, Rio [Nuclear and Biophysics Research Group, Dept. of Physics, Bandung Institute of Technology, Jl.Ganesha 10, Bandung, 40132 (Indonesia)

2012-06-06

283

Journal of Coastal Research SI 59 98-110 West Palm Beach, Florida 2011 New Ebb-Tidal Delta at an Old Inlet, Shark River Inlet, New Jersey  

E-print Network

at an Old Inlet, Shark River Inlet, New Jersey Tanya M. Beck and Nicholas C. Kraus ABSTRACT BECK, T.M. and KRAUS, N.C., 2011. New Ebb-Tidal Delta at an Old Inlet, Shark River Inlet, New Jersey. In: Roberts, T River Inlet, located on the north New Jersey coast, is served by a federal navigation channel that has

US Army Corps of Engineers

284

Denitrification and Oxygen Cycling in Saanich Inlet  

NASA Astrophysics Data System (ADS)

Saanich Inlet, British Columbia is a seasonally anoxic fjord and therefore an ideal location to study seasonal changes in productivity and respiration. We have collected monthly profiles of dissolved oxygen and oxygen/nitrogen/argon ratios in this estuary since April 2008. These measurements allow us to explain deviations of gas concentrations from equilibrium with the atmosphere by separating the effects of physical processes, which affect all three gases, from biological processes, which only affect oxygen and nitrogen. The bottom water in this fjord becomes anoxic due to a sill that restricts water inflow and high rates of primary productivity at the surface that result in aerobic decomposition at depth. This profile is reset on an irregular basis by flushing events that allow oxygenated water from outside Saanich Inlet to enter the basin. An increase in oxygen concentrations below 90 m between sampling in April and May 2008 suggested that a renewal occurred between these cruises. Data from the VENUS project, which has deployed a CTD at 96 m in Saanich Inlet, confirms this hypothesis. Although aerobic respiration resulted in a continuous depletion in oxygen at intermediate depths during the summer, the dissolved nitrogen/argon profile over the full depth of the inlet remained remarkably constant from May through August. A persistent maximum in the nitrogen/argon ratio of 5% above the expected ratio at equilibrium was observed in the deepest 25 m at our station. The stability of the profile over the summer implies that a steady state was quickly established following the renewal. The excess nitrogen gas was produced by denitrifying and/or anammox bacteria that decompose organic matter in suboxic environments. Denitrification involves the use of nitrate to oxidize organic carbon and anammox utilizes nitrite to oxidize ammonium. Despite denitrifying bacteria preferentially reducing 14N-NO3- to produce isotopically light N2, the maximum ?15N- N2 of 1.2‰ coincided with the maximum nitrogen gas excess. This observation suggests that when denitrification occurred, all available nitrate was converted to N2 and that the nitrate consumed was substantially enriched in 15N relative to natural isotopic abundances. We will explore our data set using a mass balance approach.

Manning, C. C.; Hamme, R. C.; Bourbonnais, A.

2008-12-01

285

Axial convergence fronts in a barotropic tidal inlet—sand shoal inlet, VA  

Microsoft Academic Search

An axial convergence front system in Sand Shoal Inlet, VA, is analyzed. The fronts, which are parallel to the main channel and mostly within the channel, occur during different tidal stages within a 13-h observation period. A 25-ft boat is used to tow an acoustic Doppler current profiler to measure velocity profiles along an hour-glass shaped ship track. Salinity and

Chunyan Li

2002-01-01

286

NASCRIN - NUMERICAL ANALYSIS OF SCRAMJET INLET  

NASA Technical Reports Server (NTRS)

The NASCRIN program was developed for analyzing two-dimensional flow fields in supersonic combustion ramjet (scramjet) inlets. NASCRIN solves the two-dimensional Euler or Navier-Stokes equations in conservative form by an unsplit, explicit, two-step finite-difference method. A more recent explicit-implicit, two-step scheme has also been incorporated in the code for viscous flow analysis. An algebraic, two-layer eddy-viscosity model is used for the turbulent flow calculations. NASCRIN can analyze both inviscid and viscous flows with no struts, one strut, or multiple struts embedded in the flow field. NASCRIN can be used in a quasi-three-dimensional sense for some scramjet inlets under certain simplifying assumptions. Although developed for supersonic internal flow, NASCRIN may be adapted to a variety of other flow problems. In particular, it should be readily adaptable to subsonic inflow with supersonic outflow, supersonic inflow with subsonic outflow, or fully subsonic flow. The NASCRIN program is available for batch execution on the CDC CYBER 203. The vectorized FORTRAN version was developed in 1983. NASCRIN has a central memory requirement of approximately 300K words for a grid size of about 3,000 points.

Kumar, A.

1994-01-01

287

Active Flow Control on an Aggressive Serpentine Duct Inlet  

NASA Astrophysics Data System (ADS)

For military applications, inlet designs are constrained by low observability requirements, which call for the use of a serpentine inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the aircraft. For this reason, aggressive inlets can have a large impact on overall system efficiency. Experiments utilizing active flow control to mitigate separation in a highly aggressive serpentine duct (L/D=1.5), at Mach numbers up to 0.45, were conducted. Specifically, steady and unsteady flow control techniques were compared by measuring the static pressures along the inlet walls, the pressure recovery and distortion at the AIP, and the velocity field inside the duct using Particle Image Velocimetry. Through these experiments a better understanding of the highly three dimensional flow interactions was formulated.

Vaccaro, John; Amitay, Michael

2008-11-01

288

Effect of Blowing on Boundary Layer of Scarf Inlet  

NASA Technical Reports Server (NTRS)

When aircraft operate in stationary or low speed conditions, airflow into the engine accelerates around the inlet lip and pockets of turbulence that cause noise and vibration can be ingested. This problem has been encountered with engines equipped with the scarf inlet, both in full scale and in model tests, where the noise produced during the static test makes it difficult to assess the noise reduction performance of the scarf inlet. NASA Langley researchers have implemented boundary layer control in an attempt to reduce the influence of the flow nonuniformity in a 12-in. diameter model of a high bypass fan engine mounted in an anechoic chamber. Static pressures and boundary layer profiles were measured in the inlet and far field acoustic measurements were made to assess the effectiveness of the blowing treatment. The blowing system was found to lack the authority to overcome the inlet distortions. Methods to improve the implementation of boundary layer control to reduce inlet distortion are discussed.

Gerhold, Carl H.; Clark, Lorenzo R.

2004-01-01

289

Boundary-layer-ingesting inlet flow control system  

NASA Technical Reports Server (NTRS)

A system for reducing distortion at the aerodynamic interface plane of a boundary-layer-ingesting inlet using a combination of active and passive flow control devices is disclosed. Active flow control jets and vortex generating vanes are used in combination to reduce distortion across a range of inlet operating conditions. Together, the vortex generating vanes can reduce most of the inlet distortion and the active flow control jets can be used at a significantly reduced control jet mass flow rate to make sure the inlet distortion stays low as the inlet mass flow rate varies. Overall inlet distortion, measured and described as average SAE circumferential distortion descriptor, was maintained at a value of 0.02 or less. Advantageous arrangements and orientations of the active flow control jets and the vortex generating vanes were developed using computational fluid dynamics simulations and wind tunnel experimentations.

Owens, Lewis R. (Inventor); Allan, Brian G. (Inventor)

2010-01-01

290

Hypersonic Inlet for a Laser Powered Propulsion System  

NASA Astrophysics Data System (ADS)

Propulsion within the lightcraft concept is produced via laser induced detonation of an incoming hypersonic air stream. This process requires suitable engine configurations that offer good performance over all flight speeds and angles of attack to ensure the required thrust is maintained. Stream traced hypersonic inlets have demonstrated the required performance in conventional hydrocarbon fuelled scramjet engines, and has been applied to the laser powered lightcraft vehicle. This paper will outline the current methodology employed in the inlet design, with a particular focus on the performance of the lightcraft inlet at angles of attack. Fully three-dimensional turbulent computational fluid dynamics simulations have been performed on a variety of inlet configurations. The performance of the lightcraft inlets have been evaluated at differing angles of attack. An idealized laser detonation simulation has also been performed to validate that the lightcraft inlet does not unstart during the laser powered propulsion cycle.

Harrland, Alan; Doolan, Con; Wheatley, Vincent; Froning, Dave

2011-11-01

291

Results from computational analysis of a mixed compression supersonic inlet  

NASA Technical Reports Server (NTRS)

A numerical study was performed to simulate the critical flow through a supersonic inlet. This flowfield has many phenomena such as shock waves, strong viscous effects, turbulent boundary layer development, boundary layer separations and mass flow suction through the walls (bleed). The computational tools used in this study were two full Navier-Stokes (FNS) codes. The supersonic inlet that was analyzed in this study is the Variable Diameter Centerbody (VDC), inlet. This inlet is a candidate concept for the next generation supersonic transport. Application of the code to the inlet geometry involved effort in generating an efficient grid geometry and specifying boundary conditions, particularly in the bleed region and at the outflow boundary. Results for a critical inlet operation compare favorably to Method of Characteristics predictions and experimental data.

Saunders, J. D.; Keith, T. G., Jr.

1991-01-01

292

CFD numerical simulation of Archimedes spiral inlet hydrocyclone  

NASA Astrophysics Data System (ADS)

For traditional linear type inlet, hydrocyclone has an unstable inner field, high turbulence intensity and low separation efficiency, this paper proposes an inlet mode that uses an Archimedes spiral hydrocyclone. A Mixture liquid-solid multiphase flow model combined with the kinetic theory of granular flow was used to simulate the high concentration water-sand-air three-phase flow in a hydrocyclone. We analyzed the pressure field, velocity field and turbulent kinetic energy and compared with traditional linear type inlet hydrocyclone inner field. The results show that Archimedes spiral inlet hydrocyclone's pressure field is evenly distributed. The Archimedes spiral inlet hydrocyclone can guide and accelerate the mixture flow and produce small forced vortex and less short circuit flow. The particles easily go to the outer vortex and are separated. The Archimedes spiral inlet hydrocyclone has effectively improved the stability of inner flow field and separation efficiency.

Zhang, L.; Wei, L.; Chang, B. H.; Xing, J. L.; Jia, K.

2013-12-01

293

Zonal analysis of two high-speed inlets  

NASA Technical Reports Server (NTRS)

Using a zonal technique, thin layer Navier-Stokes solutions for two high speed inlet geometries are presented and compared with experimental data. The first configuration consists of a 3-D inlet preceded by a sharp flat plate. Results with two different grids demonstrate the importance of adequate grid refinement in high speed internal flow computations. The fine grid solution has reasonably good agreement with experimental heat transfer and pressure values inside the inlet. The other configuration consists of a 3-D inlet mounted on a research hypersonic forebody. Numerical results for this configuration have good agreement with experimental pressure data along the forebody, but not inside the inlet. A more refined grid calculation is currently being done to better predict the flowfield in the inlet.

Dilley, A. D.; Switzer, G. F.; Eppard, W. M.

1991-01-01

294

Calculation of inlet flow fields by an implicit technique  

NASA Technical Reports Server (NTRS)

Two-dimensional inlet flow fields in a supersonic free stream are calculated by an implicit, shock-capturing, finite-difference method. The Euler equations are subjected to a general curvilinear transformation and a body-fitted coordinate system is employed. The method is used to solve supercritical, critical, and subcritical flow fields which are simulated by prescribing appropriate conditions at the inlet outflow boundary. Results are presented for a drooped-cowl inlet.

Biringen, S.; Chaussee, D. S.; Mcmillan, O. J.

1980-01-01

295

Cryogenic-coolant He-4-superconductor interaction  

NASA Technical Reports Server (NTRS)

The thermodynamic and thermal interaction between a type 2 composite alloy and cryo-coolant He4 was studied with emphasis on post quench phenomena of formvar coated conductors. The latter were investigated using a heater simulation technique. Overall heat transfer coefficients were evaluated for the quench onset point. Heat flux densities were determined for phenomena of thermal switching between a peak and a recovery value. The study covered near saturated liquid, pressurized He4, both above and below the lambda transition, and above and below the thermodynamic critical pressure. In addition, friction coefficients for relative motion between formvar insulated conductors were determined.

Caspi, S.; Lee, J. Y.; Kim, Y. I.; Allen, R. J.; Frederking, T. H. K.

1978-01-01

296

Microstructural characterization of primary coolant pipe steel  

SciTech Connect

Atom probe field-ion microscopy, analytical electron microscopy, and optical microscopy have been used to investigate the changes that occur in the microstructure of cast CF 8 primary coolant pipe stainless steel after long term thermal aging. The cast duplex microstructure consisted of austenite with 15% delta-ferrite. Investigation of the aged material revealed that the ferrite spinodally decomposed into a fine scaled network of ..cap alpha.. and ..cap alpha..'. A fine G-phase precipitate was also observed in the ferrite. The observed degradation in mechanical properties is probably a consequence of the spinodal decomposition in the ferrite.

Miller, M.K.; Bentley, J.

1986-01-01

297

Hydrogen generation during fuel/coolant interactions  

SciTech Connect

During a severe nuclear plant accident, molten fuel can contact water in the core region, the lower plenum, or in the cavity below the reactor vessel. The interactions that take place can vary from benign boiling to explosive vaporization. If the fuel contains a metallic component, rapid oxidation of the metal can occur during the fuel/coolant interaction (FCI). The hydrogen generated from this reaction can increase the threat to containment integrity. Experiments have been conducted with 10 to 20 kg of two kinds of thermite-generated molten fuel stimulants: corium and iron-aluminum oxide. The experiments are described in this paper and predictions are made based on experimental observations.

Young, M.F.; Berman, M. (Sandia National Labs., Albuquerque, NM (USA)); Pong, L.T. (Technadyne Engineering Consultants, Inc., Albuquerque, NM (USA))

1989-01-01

298

Analysis of coolant flow and heat transfer in the SSME HPOTP Number 4 bearing assembly  

NASA Technical Reports Server (NTRS)

The PHOENICS code has been applied to simulate the flow of liquid oxygen through the number 4 ball bearing assembly of the Space Shuttle Main Engine High-Pressure Oxidizer Turbopump. The Body-Fitted Coordinate system capability of PHOENICS was utilized to create a geometrically accurate model. Effects accounted for by the model include the rotation rate of the calculation domain, viscous heating in the liquid oxygen and two-phase effects due to LOX boiling. A separation program was used to account for conduction within a ball bearing element which was coupled with the PHOENICS flow and heat transfer analysis. Solutions have been obtained for the velocity and temperature fields within the LOX coolant and the temperature within the ball element. The predicted ball temperatures indicate that the coolant is boiling in the region near the ball surface.

Owens, S. F.; Costes, N. C.

1990-01-01

299

Flow control optimization in a jet engine serpentine inlet duct.  

E-print Network

??Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis… (more)

Kumar, Abhinav

2009-01-01

300

Inlet-Compressor Analysis Using Coupled CFD Codes  

NASA Technical Reports Server (NTRS)

Propulsion performance and operability are key factors in the development of a successful aircraft. For high-speed supersonic aircraft, mixed-compression inlets offer high performance but are susceptible to an instability referred to as unstart. An unstart occurs when a disturbance originating in the atmosphere or the engine causes the shock system to be expelled from the inlet. This event can have adverse effects on control of the aircraft, which is unacceptable for a passenger plane such as the high speed civil transport (HSCT). The ability to predict the transient response of such inlets to flow perturbations is, therefore, important to the proper design of the inlet and the control measures used to prevent unstart. Computational fluid dynamics (CFD) is having an increasing role in the analysis of individual propulsion components. isolated inlet studies are relatively easy to perform, but a major uncertainty is the boundary condition used at the inlet exit to represent the engine - the so-called compressor face boundary condition. A one-dimensional (I-D) Euler inlet simulation (ref. 1) showed that the predicted inlet unstart tolerance to free-stream pressure perturbations can vary by as much as a factor of about six, depending on the boundary condition used. Obviously, a thorough understanding of dynamic interactions between inlets and compressors/fans is required to provide the proper boundary condition.

Cole, Gary; Suresh, Ambady; Townsend, Scott

1998-01-01

301

Tidal inlet variability in Mississippi River delta plain  

SciTech Connect

Stratigraphic sequences of deltaic and shallow marine origin commonly contain sand bodies transgressively overlying lower delta-plain and delta-front deposits. Although generally ascribed to barriers formed during the destructive phase of the delta cycle, most of this sand is probably of tidal-inlet origin because of the high preservation potential for sediment deposited below the base of the retreating shoreface in deep migratory tidal channels and their associated tidal deltas. To facilitate the identification of such units, this paper reviews the temporal evolution of the inlet sand bodies found along the rapidly transgressive shoreline of the abandoned Holocene Mississippi River deltas. This study also reveals that tide dominance of a coastline is not simply a function of tide range and wave height; it depends largely on the tidal prism, an inlet parameter which, in Louisiana, changes rapidly over time. Three distinct stages can be identified in the evolutionary sequence for Louisiana tidal inlets: (1) wave-dominated inlets with flood-tidal deltas, (2) tide-dominated inlets with large ebb deltas, and (3) wide, transitional inlets with sand bodies confined to the throat section. As the inlets migrate during the transgression, they will leave behind on the continental shelf, tidal sand bodies with a landward succession of facies changing from those characteristic of wave dominance, into tide dominance, and back again to transitional or wave-dominated inlets.

Levin, D.; Nummedal, D.; Penland, S.

1983-09-01

302

Acoustic Environment of Admiralty Inlet: Broadband Noise Measurements  

SciTech Connect

Admiralty Inlet has been selected as a potential tidal energy site. It is located near shipping lanes, is a highly variable acoustic environment, and is frequented by the highly endangered southern resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines at Admiralty Inlet. Of particular concern is the potential for blade strike or other negative interactions between the SRKW and the tidal turbine. A variety of technologies including passive and active monitoring systems are being considered as potential tools to determine the presence of SRKW in the vicinity of the turbines. Broadband noise level measurements are critical for the determination of design and operation specifications of all marine and hydrokinetic energy capture technologies. Acoustic environment data at the proposed site was acquired at different depths using a cabled vertical line array (VLA) with four calibrated hydrophones. The sound pressure level (SPL) power spectrum density was estimated based on the fast Fourier transform. This study describes the first broadband SPL measurements for this site at different depths with frequency ranging from 10 kHz to 480 kHz in combination with other information. To understand the SPL caused by this bedload transport, three different pressure sensors with temperature and conductivity were also assembled on the VLA to measure the conditions at the hydrophone deployment depth. The broadband SPL levels at frequency ranges of 3 kHz to 7 kHz as a function of depth were estimated. Only the hydrophone at an average depth of 40 m showed the strong dependence of SPL with distance from the bottom, which was possibly caused by the cobbles shifting on the seabed. Automatic Identification System data were also studied to understand the SPL measurements.

Xu, Jinshan; Deng, Zhiqun; Martinez, Jayson J.; Carlson, Thomas J.; Myers, Joshua R.; Weiland, Mark A.; Jones, Mark E.

2011-09-30

303

Porous coolant tube holder for fuel cell stack  

DOEpatents

A coolant tube holder for a stack of fuel cells is a gas porous sheet of fibrous material adapted to be sandwiched between a cell electrode and a nonporous, gas impervious flat plate which separates adjacent cells. The porous holder has channels in one surface with coolant tubes disposed therein for carrying coolant through the stack. The gas impervious plate is preferably bonded to the opposite surface of the holder, and the channel depth is the full thickness of the holder.

Guthrie, Robin J. (East Hartford, CT)

1981-01-01

304

Hydrogen generation during fuel-coolant interactions  

SciTech Connect

During a severe nuclear plant accident, molten fuel can contact water in the core region, the lower plenum, or in the cavity below the reactor vessel. The interactions that take place can vary from benign boiling to explosive vaporization. If the fuel contains a metallic component, rapid oxidation of the metal can occur during the fuel-coolant interaction (FCI). The hydrogen generated from this reaction can increase the threat to containment integrity. Experiments have been conducted with 10 to 20 kg of two kinds of thermite-generated molten fuel simulants: corium and iron-aluminum oxide. Both saturated and subcooled water were employed as coolants. Explosive and nonexplosive FCIs were observed. Up to 30% of the metal was reacted in some cases. For some of the tests, the extent of reaction appeared to depend more on the water subcooling than on the degree of fragmentation as measured by post-test sieving. Models of hydrogen generation are proposed and compared to a broad range of experiments. Predictions agree qualitatively with many of the experimental observations. A more accurate model of hydrogen generation would have to be coupled to a dynamic thermal-hydraulic calculation of the important phases of an FCI: coarse mixing, fine fragmentation, explosion propagation and vapor expansion.

Young, M.F.; Berman, M.; Pong, L.T.

1986-01-01

305

An evaluation of thermal energy storage options for precooling gas turbine inlet air  

NASA Astrophysics Data System (ADS)

Several approaches have been used to reduce the temperature of gas turbine inlet air. One of the most successful uses off-peak electric power to drive vapor-compression-cycle ice makers. The ice is stored until the next time high ambient temperature is encountered, when the ice is used in a heat exchanger to cool the gas turbine inlet air. An alternative concept would use seasonal thermal energy storage to store winter chill for inlet air cooling. The objective of this study was to compare the performance and economics of seasonal thermal energy storage in aquifers with diurnal ice thermal energy storage for gas turbine inlet air cooling. The investigation consisted of developing computer codes to model the performance of a gas turbine, energy storage system, heat exchangers, and ancillary equipment. The performance models were combined with cost models to calculate unit capital costs and levelized energy costs for each concept. The levelized energy cost was calculated for three technologies in two locations (Minneapolis, Minnesota and Birmingham, Alabama). Precooling gas turbine inlet air with cold water supplied by an aquifer thermal energy storage system provided lower cost electricity than simply increasing the size of the turbine for meteorological and geological conditions existing in the Minneapolis vicinity. A 15 to 20 percent cost reduction resulted for both 0.05 and 0.2 annual operating factors. In contrast, ice storage precooling was found to be between 5 and 20 percent more expensive than larger gas turbines for the Minneapolis location. In Birmingham, aquifer thermal energy storage precooling was preferred at the higher capacity factor and ice storage precooling was the best option at the lower capacity factor. In both cases, the levelized cost was reduced by approximately 5 percent when compared to larger gas turbines.

Antoniak, Z. I.; Brown, D. R.; Drost, M. K.

1992-12-01

306

Inlet distortion in engines on VSTOL aircraft  

NASA Technical Reports Server (NTRS)

This report presents the results of a research program on inlet distortion in engines on VSTOL aircraft carried out at the MIT Gas Turbine Laboratory during the period Oct. 1989 - Dec. 1993. The program focused on the development of three dimensional flow computational methodology for predicting the effects of nonuniform flow on the performance of aircraft engines in VSTOL aircraft, the development of a three dimensional instability analysis of flow in multistage axial compressors, and the preliminary applications of these newly developed methodologies for elucidating the effects of flow three dimensionality. The accomplishments of the program are brought out when the current status of predictive capabilities for three dimensional flow instabilities in compressors is assessed against that in 1989.

Tan, Choon S.; Greitzer, Edward M.

1994-01-01

307

Inlet-Compressor Analysis using Coupled CFD Codes  

NASA Technical Reports Server (NTRS)

Propulsion performance and operability are key factors in the development of a successful aircraft. For high-speed supersonic aircraft, mixed-compression inlets offer high performance but are susceptible to an instability referred to as unstart. An unstart occurs when a disturbance originating in the atmosphere or the engine causes the shock system to be expelled from the inlet. This event can have adverse effects on control of the aircraft, which is unacceptable for a passenger plane such as the high speed civil transport (HSCT). The ability to predict the transient response of such inlets to flow perturbations is, therefore, important to the proper design of the inlet and the control measures used to prevent unstart. Computational fluid dynamics (CFD) is having an increasing role in the analysis of individual propulsion components. Isolated inlet studies are relatively easy to perform, but a major uncertainty is the boundary condition used at the inlet exit to represent the engine - the so-called compressor face boundary condition. A one-dimensional (1-D) Euler inlet simulation showed that the predicted inlet unstart tolerance to free-stream pressure perturbations can vary by as much as a factor of about six, depending on the boundary condition used. Obviously a thorough understanding of dynamic interactions between inlets and compressors/fans is required to provide the proper boundary condition. To aid in this understanding and to help evaluate possible boundary conditions, an inlet-engine experiment was conducted at the University of Cincinnati. The interaction of acoustic pulses, generated in the inlet, with the engine were investigated. Because of the availability of experimental data for validation, it was decided to simulate the experiment using CFD. The philosophy here is that the inlet-engine system is best simulated by coupling (existing) specialized CFD component-codes. The objectives of this work were to aid in a better understanding of inlet-compressor interaction physics and the formulation of a more realistic compressor-face boundary condition for time-accurate CFD simulations of inlets. Previous simulations have used 1-D Euler engine simulations in conjunction with 1-D Euler and axisymmetric Euler inlet simulations. This effort is a first step toward CFD simulation of an entire engine by coupling multidimensional component codes.

Cole, Gary; Suresh, Ambady; Townsend, Scott

1999-01-01

308

Analysis of Loss-of-Coolant Accidents in the NBSR  

SciTech Connect

This report documents calculations of the fuel cladding temperature during loss-of-coolant accidents in the NBSR. The probability of a pipe failure is small and procedures exist to minimize the loss of water and assure emergency cooling water flows into the reactor core during such an event. Analysis in the past has shown that the emergency cooling water would provide adequate cooling if the water filled the flow channels within the fuel elements. The present analysis is to determine if there is adequate cooling if the water drains from the flow channels. Based on photographs of how the emergency water flows into the fuel elements from the distribution pan, it can be assumed that this water does not distribute uniformly across the flow channels but rather results in a liquid film flowing downward on the inside of one of the side plates in each fuel element and only wets the edges of the fuel plates. An analysis of guillotine breaks shows the cladding temperature remains below the blister temperature in fuel plates in the upper section of the fuel element. In the lower section, the fuel plates are also cooled by water outside the element that is present due to the hold-up pan and temperatures are lower than in the upper section. For small breaks, the simulation results show that the fuel elements are always cooled on the outside even in the upper section and the cladding temperature cannot be higher than the blister temperature. The above results are predicated on assumptions that are examined in the study to see their influence on fuel temperature.

Baek J. S.; Cheng L.; Diamond, D.

2014-05-23

309

Critical Propulsion Components. Volume 4; Inlet and Fan/Inlet Accoustics Team  

NASA Technical Reports Server (NTRS)

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/Inlet Acoustic Team.

2005-01-01

310

Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants  

SciTech Connect

The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.

Su-Jong Yoon; Piyush Sabharwall

2014-07-01

311

Preparation, conduct, and experimental results of the AVR loss-of-coolant accident simulation test  

SciTech Connect

A loss-of-coolant accident (LOCA) is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into small high-temperature gas-cooled reactor (HTGR) design, LOCA simulation tests have been conducted at the Arbeitsgemeinschaft Versuchsreaktor (AVR), the German pebble-bed-high-temperature reactor plant. The AVR is the only nuclear power plant ever to have been intentionally subjected to LOCA conditions without emergency cooling. This paper presents the planning and licensing activities including pretest predictions performed for the LOCA test are described, and the conduct of the test and experimental results. The LOCA test was planned to create conditions that would exist if a rapid LOCA occurred with the reactor operating at full power. The test demonstrated this reactor's safe response to an accident in which the coolant escapes from the reactor core and no emergency system is available to provide coolant flow to the core. The test is of special interest because it demonstrates the inherent safety features incorporated into optimized modular HTGR designs. The main LOCA test lasted for 5 days. After the test began, core temperatures increased for {approx}13 h and then gradually and continually decreased as the rate of heat dissipation from the core exceeded the simulated decay power. Throughout the test, temperatures remained below limiting values for the core and other reactor components.

Kruger, K.; Bergerfurth, A.; Burger, S.; Pohl, P.; Wimmers, M. (Arbeitsgemeinschaft Versuchsreaktor AVR GmbH, Duesseldorf (DE)); Cleveland, J.C. (Oak Ridge National Lab., TN (United States))

1991-02-01

312

Loss-of-coolant accident experiment at the AVR gas-cooled reactor  

SciTech Connect

A landmark safety test has been conducted at the AVR-reactor, a high-temperature gas-cooled reactor (HTGR) in the Federal Republic of Germany owned by the Arbeitsgemeinschaft Versuchsreaktor, AVR in Juelich. The 46-MW(t), 15-MW(e) AVR reactor was subjected to a simulated loss-of-coolant accident (LOCA), a very severe occurrence in which the coolant escapes from the reactor core and no emergency system provides coolant flow to the core. The test, which demonstrated the inherently safe response of this reactor to a LOCA, marked the first time ever that a reactor has been intentionally subjected to loss-of-coolant conditions without emergency cooling. Oak Ridge National Laboratory (ORNL) and General Atomics participated in the test by working with AVR staff by jointly performing the analyses needed to obtain the license to conduct the test and by performing post test analyses. This participation was carried out under the cooperative AVR Subprogram which is conducted within the US/FRG Agreement for Cooperation in Gas-Cooled Reactor Development. 7 figs.

Krueger, K. (Arbeitsgemeinschaft Versuchs-Reaktor GmbH, Juelich (Germany, F.R.)); Cleveland, J. (Oak Ridge National Lab., TN (USA))

1990-01-01

313

Parametric Analysis of a Hypersonic Inlet using Computational Fluid Dynamics  

NASA Astrophysics Data System (ADS)

For CFD validation, hypersonic flow fields are simulated and compared with experimental data specifically designed to recreate conditions found by hypersonic vehicles. Simulated flow fields on a cone-ogive with flare at Mach 7.2 are compared with experimental data from NASA Ames Research Center 3.5" hypersonic wind tunnel. A parametric study of turbulence models is presented and concludes that the k-kl-omega transition and SST transition turbulence model have the best correlation. Downstream of the flare's shockwave, good correlation is found for all boundary layer profiles, with some slight discrepancies of the static temperature near the surface. Simulated flow fields on a blunt cone with flare above Mach 10 are compared with experimental data from CUBRC LENS hypervelocity shock tunnel. Lack of vibrational non-equilibrium calculations causes discrepancies in heat flux near the leading edge. Temperature profiles, where non-equilibrium effects are dominant, are compared with the dissociation of molecules to show the effects of dissociation on static temperature. Following the validation studies is a parametric analysis of a hypersonic inlet from Mach 6 to 20. Compressor performance is investigated for numerous cowl leading edge locations up to speeds of Mach 10. The variable cowl study showed positive trends in compressor performance parameters for a range of Mach numbers that arise from maximizing the intake of compressed flow. An interesting phenomenon due to the change in shock wave formation for different Mach numbers developed inside the cowl that had a negative influence on the total pressure recovery. Investigation of the hypersonic inlet at different altitudes is performed to study the effects of Reynolds number, and consequently, turbulent viscous effects on compressor performance. Turbulent boundary layer separation was noted as the cause for a change in compressor performance parameters due to a change in Reynolds number. This effect would not be noticeable if laminar flow was assumed. Mach numbers up to 20 are investigated to study the effects of vibrational and chemical non-equilibrium on compressor performance. A direct impact on the trends on the kinetic energy efficiency and compressor efficiency was found due to dissociation.

Oliden, Daniel

314

LAKE WORTH INLET (PALM BEACH HARBOR) NAVIGATION IMPROVEMENT PROJECT  

E-print Network

LAKE WORTH INLET (PALM BEACH HARBOR) NAVIGATION IMPROVEMENT PROJECT PALM BEACH COUNTY, FLORIDA 24 January 2014 ABSTRACT: Lake Worth Inlet connects Palm Beach Harbor to the Atlantic Ocean. The port is located in Riviera Beach, Palm Beach County, Florida. The Port of Palm Beach is the fourth busiest

US Army Corps of Engineers

315

A Morphing Composite Air Inlet with Multiple Stable Shapes  

Microsoft Academic Search

The morphing air inlet is a structure with shape-changing capability. Shapes include that which is flush with an aerodynamic surface and also a submerged divergent channel suitable for use in an aircraft cooling system. The air inlet structure is multistable in order that it can ‘snap’ open and closed and not require any external holding force to maintain its geometry.

S. Daynes; P. M. Weaver; J. A. Trevarthen

2011-01-01

316

Physical controls on the dynamics of inlet sandbar systems  

Microsoft Academic Search

Knowledge of the physical processes acting at inlet systems and their interaction with sediments and sediment bodies is important to the understanding of such environments. The objectives of this study are to identify and assess the relative importance of the controlling processes across the complex sandbar system at the Teign inlet (Teignmouth, UK) through the combined application of a numerical

E. Siegle; D. A. Huntley; M. A. Davidson

2004-01-01

317

A multiobjective shape optimization study for a subsonic submerged inlet  

Microsoft Academic Search

The purpose of the present work is to summarize the findings of a multiobjective shape optimization study conducted for a subsonic submerged air vehicle inlet. The objective functions of the optimization problem are distortion and swirl indices defined by the distribution of flow parameters over the exit cross-section of the inlet. The geometry alteration is performed by placing a protrusion

Ezgi S. Taskinoglu

2004-01-01

318

Serpentine Inlet Performance Enhancement Using Vortex Generator Based Flow Control  

Microsoft Academic Search

In order to provide the line of-sight blockage of the engine face for an advanced Uninhabited Combat Air Vehicle(UCAV), a highly curved serpentine inlet is proposed and experimentally studied. Based on the static pressure distribut ion measurement along the wall, the flow separation is found at the top wall of the second S duct for the baseline inlet design, which

Shu SUN; Rong-wei GUO

2006-01-01

319

Stall transients including effects of inlet distortion and intake geometry  

Microsoft Academic Search

Combined cycle theory and its enabling approximations (differential equations for stall transients) are reviewed. Developments to the theory are described: amendment to include inlet flow distortion and estimation of steady stall margin. Advances in improving the physical models used in the theory, especially those pertaining to the inlet flow, compressibility, and the axisymmetric characteristic are discussed. Computational efforts to properly

F. K. Moore

1992-01-01

320

Experimental Investigation of Actuators for Flow Control in Inlet Ducts  

Microsoft Academic Search

Attractive to aircraft designers are compact inlets, which implement curved flow paths to the compressor face. These curved flow paths could be employed for multiple reasons. One of which is to connect the air intake to the engine embedded in the aircraft body. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic

John Vaccaro; Yossef Elimelech; Michael Amitay

2010-01-01

321

The Effect of Nonuniform Inlet Conditions on Annular Diffusers  

Microsoft Academic Search

Most practical diffusers have complex 3D geometries and may have highly disturbed inlet flows. The performance of diffusers designed for optimum pressure recovery is governed by flow separation which can be very sensitive to inlet perturbations. We are examining the effect of upstream disturbances on the performance of practical annular diffusers. Experiments are conducted in an annular diffuser sector containing

Angelina Padilla; Chris Elkins; John Eaton

2010-01-01

322

Aerodynamic and directional acoustic performance of a scoop inlet  

NASA Technical Reports Server (NTRS)

Aerodynamic and directional acoustic performances of a scoop inlet were studied. The scoop inlet is designed with a portion of the lower cowling extended forward to direct upward any noise that is propagating out the front of the engine toward the ground. The tests were conducted in an anechoic wind tunnel facility at free stream velocities of 0, 18, 41, and 61 m/sec and angles of attack from -10 deg to 120 deg. Inlet throat Mach number was varied from 0.30 to 0.75. Aerodynamically, at a free stream velocity of 41 m/sec, the design throat Mach number (0.63), and an angle of attack of 50 deg, the scoop inlet total pressure recovery was 0.989 and the total pressure distortion was 0.15. The angles of attack where flow separation occurred with the scoop inlet were higher than those for a conventional symmetric inlet. Acoustically, the scoop inlet provided a maximum noise reduction of 12 to 15 db below the inlet over the entire range of throat Mach number and angle of attack at a free-stream velocity of 41 m/sec.

Abbott, J. M.; Dietrich, D. A.

1977-01-01

323

The Simulation for Pressure Loss of Microchannel Heat Sinks Inlet  

Microsoft Academic Search

Microchannel device is one of the prominent applications in micro and nano technologies. Basic theory for micro fluid is developing, but pressure loss in inlet and outlet of microchannel is paid little attention. Some researches show that the pressure loss in microchannel is only 10 percent, while that in inlet and outlet is up to 90 percent. So it becomes

Wenzhong Lou; Xiuli Yi; Bin Qi

2007-01-01

324

Validation of WIND for a Series of Inlet Flows  

NASA Technical Reports Server (NTRS)

Validation assessments compare WIND CFD simulations to experimental data for a series of inlet flows ranging in Mach number from low subsonic to hypersonic. The validation procedures follow the guidelines of the AIAA. The WIND code performs well in matching the available experimental data. The assessments demonstrate the use of WIND and provide confidence in its use for the analysis of aircraft inlets.

Slater, John W.; Abbott, John M.; Cavicchi, Richard H.

2002-01-01

325

Isolated testing of highly maneuverable inlet con cepts  

NASA Technical Reports Server (NTRS)

Ten percent scale models of a Mach 2.2 two dimensional inlet and a Mach 2.0 axisymmetric inlet were tested in the NASA Lewis Research Center 8'x6' Supersonic Wind Tunnel as part of a cooperative effort with the McDonnell Aircraft Company. The objective of this effort was to test methods designed to increase the maneuvering performance of fighter aircraft inlets. Maneuvering improvement concepts were tested up to 40-deg angle of attack for Mach numbers of 0.6 and 0.9, and up to 25 deg for Mach numbers 1.2 and 1.4. Maneuvering improvement concepts included a rotating cowl lip, auxiliary inlets aft of the inlet throat, and a retracting centerbody for the axisymmetric inlet. Test results show that the rotating cowl design was effective in improving subsonic maneuvering performance for both inlets. Auxiliary inlets did not produce significant performance increases for either model. The retracted centerbody resulted in some performance benefits at high angles of attack. None of the maneuvering improvement concepts were effective at Mach 1.2 and 1.4.

Norby, W. P.; Haeffele, B. A.; Burley, R. R.

1986-01-01

326

Assessment of tidal inlet evolution and stability using sediment budget computations and hydraulic parameter analysis  

Microsoft Academic Search

Research into the response of coastlines to the opening and stabilisation of inlets has been limited by the availability of suitable data, the shortcomings of existing formulae when applied to different inlets, and the difficulties particular to multi-inlet situations. Our appraisal of methodologies for studying inlet dynamics leads us to formulate a new approach for investigating inlet evolution and stability

A. Pacheco; A. Vila-Concejo; Ó. Ferreira; J. A. Dias

2008-01-01

327

Application of quadratic optimization to supersonic inlet control  

NASA Technical Reports Server (NTRS)

The application of linear stochastic optimal control theory to the design of the control system for the air intake (inlet) of a supersonic air-breathing propulsion system is discussed. The controls must maintain a stable inlet shock position in the presence of random airflow disturbances and prevent inlet unstart. Two different linear time invariant control systems are developed. One is designed to minimize a nonquadratic index, the expected frequency of inlet unstart, and the other is designed to minimize the mean square value of inlet shock motion. The quadratic equivalence principle is used to obtain the best linear controller that minimizes the nonquadratic performance index. The two systems are compared on the basis of unstart prevention, control effort requirements, and sensitivity to parameter variations.

Lehtinen, B.; Zeller, J. R.

1971-01-01

328

Acoustic characteristics of two hybrid inlets at forward speed  

NASA Technical Reports Server (NTRS)

A wind tunnel investigation of the acoustic and aerodynamic characteristics of two hybrid inlets installed on a JT15D-1 turbofan engine was performed. The hybrid inlets combined moderate throat Mach number and wall acoustic treatment to suppress the fan inlet noise. Acoustic and aerodynamic data were recorded over a range of flight and engine operating conditions. In a simulated flight environment, the hybrid inlets provided significant levels of suppression at both design and off-design throat Mach numbers with good aerodynamic performance. A comparison of inlet noise at quasi-static and forward-speed conditions in the wind tunnel showed a reduction in the fan tones, demonstrating the flight cleanup effect. High angles of attack produced slight increases in fan noise at the high acoustic directivity angles.

Falarski, M. D.; Moore, M. T.

1980-01-01

329

Conceptual study of a turbojet/ramjet inlet  

NASA Technical Reports Server (NTRS)

An inlet concept for separate turbojet and ramjet engines was defined and compared with an equivalent inlet for a wraparound turboramjet engine. The comparison was made for a typical high altitude hypersonic cruise vehicle where the turbojet inlet capture area was required to be half as large as the ramjet inlet capture area at cruise. The use of a shorter nacelle having substantially lower cooling requirements at cruise for the inlet concept for separate turbojet and ramjet engines is suggested. The separate engine concept better isolates the turbojet from the ramjet, requires no special close off mechanisms within the turbojet, and avoids the circumferential heat load imposed by a wraparound ramjet. A more variable geometry is required.

Weidner, J. P.

1979-01-01

330

Results from computational analysis of a mixed compression supersonic inlet  

NASA Technical Reports Server (NTRS)

A numerical study was performed to simulate the critical flow through a supersonic inlet. This flow field has many phenomena such as shock waves, strong viscous effects, turbulent boundary layer development, boundary layer separations, and mass flow suction through the walls, (bleed). The computational tools used were two full Navier-Stokes (FNS) codes. The supersonic inlet that was analyzed is the Variable Diameter Centerbody, (VDC), inlet. This inlet is a candidate concept for the next generation supersonic involved effort in generating an efficient grid geometry and specifying boundary conditions, particularly in the bleed region and at the outflow boundary. Results for a critical inlet operation compare favorably to Method of Characteristics predictions and experimental data.

Saunders, J. D.; Keith, T. G.

1991-01-01

331

Computational Analysis of a Low-Boom Supersonic Inlet  

NASA Technical Reports Server (NTRS)

A low-boom supersonic inlet was designed for use on a conceptual small supersonic aircraft that would cruise with an over-wing Mach number of 1.7. The inlet was designed to minimize external overpressures, and used a novel bypass duct to divert the highest shock losses around the engine. The Wind-US CFD code was used to predict the effects of capture ratio, struts, bypass design, and angles of attack on inlet performance. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center. Test results showed that the inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a stable operating range much larger than that of an engine. Predictions generally compared very well with the experimental data, and were used to help interpret some of the experimental results.

Chima, Rodrick V.

2011-01-01

332

Minimum weight design of a generic axisymmetric inlet  

NASA Technical Reports Server (NTRS)

A new minimum weight design method for high-speed axisymmetric inlets was demonstrated on a generic inlet. The method uses Classical Beam Theory and shell buckling to determine the minimum required equivalent isotropic thickness for a stiffened shell based on prescribed structural design requirements and load conditions. The optimum spacing and equivalent isotropic thickness of ring frame supports are computed to prevent buckling. The method thus develops a preliminary structural design for the inlet and computes the structural weight. Finite element analyses were performed on the resulting inlet design to evaluate the analytical results. Comparisons between the analytical and finite element stresses and deflections identified areas needing improvement in the analytical method. The addition of the deflection due to shear and a torsional buckling failure mode to the new method brought its results in line with those from the finite element analyses. Final validation of the new method will be made using data from actual inlets.

Nadell, Shari-Beth

1996-01-01

333

High pressure coolant effect on PVD coated inserts during end milling of Ti-6AL-4V  

NASA Astrophysics Data System (ADS)

Titanium alloys are being employed extensively in engineering and aerospace applications for their high strength to weight ratio, mechanical strength and ability to withstand high temperatures. Out of the different alloys of titanium available, the most commonly used alloy is Ti-6Al-4V. It is also called `Grade-5 titanium alloy' or '?+? titanium alloy'. High speed machining of titanium alloys generates high temperatures in the cutting zone, promoting accelerated tool wear and reducing the efficiency in metal cutting. Consequently, the ability of the coolant to remove heat from the cutting zone plays an increasingly important role in the economics of the process as well as on the life of tool inserts. With the introduction of thru-tool coolant delivery, the coolant can now be delivered directly at the point of machining without having to flood the area of machining. This research tries to address the effects that high pressure and thru-tool coolant has on insert wear while end milling Ti-6Al-4V. The parameters used in this study are speed, feed, axial depth of cut, radial depth of cut and coolant pressure. A structured design of experiments along with a central composite design approach is used to determine the main effects of coolant pressure and its interactions with the remaining parameters. The results show that, within the parameters of this experiment, coolant pressure was not a significant main effect. However, pressure seems to react positively with feed rate. Contributions from this research can be used to recommend settings of the cutting factors in order to obtain the minimal tool wear.

Sridharan, Arvind

334

Summary of recent investigations of inlet flow distortion effect on engine stability  

NASA Technical Reports Server (NTRS)

A review is presented of recent experimental results, analytical procedures and test techniques employed to evaluate the effects of inlet flow distortion on the stability characteristics of representative afterburning turbofan and turbojet compression systems. Circumferential distortions of pressure and temperature, separately and in combination are considered. Resulting engine sensitivity measurements are compared with predictions based on simplified parallel compressor models and with several distortion descriptor parameters.

Graber, E. J., Jr.; Braithwaite, W. M.

1974-01-01

335

Effect of casing treatment on performance of an inlet stage for a transonic multistage compressor  

NASA Technical Reports Server (NTRS)

An inlet stage of a transonic compressor was tested with three rotor tip casing treatment configurations: blade angle slots, circumferential grooves, and axial skewed slots. Significant increases in both rotor and stage total pressure ratio, total temperature ratio, efficiency, flow range, and very large improvements in stall margin were obtained with all three casing treatment configurations. The greatest improvement in performance was achieved with axial skewed slots.

Urasek, D. C.; Lewis, G. W., Jr.; Moore, R. D.

1976-01-01

336

Power module assemblies with staggered coolant channels  

DOEpatents

A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.

Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D

2013-07-16

337

Inlet turbulence and fan noise measured in an anechoic wind tunnel and statically with an inlet flow control device  

Microsoft Academic Search

Turbulence and acoustic measurements were taken in a wind tunnel which has demonstrated blade passage tone cutoff phenomena with forward velocity. Turbulence data were taken in a subsonic inlet at various fan speeds under static and forward velocity conditions. A honeycomb\\/screen flow control device was placed over the inlet during static tests to modify the inflow in an attempt to

L. M. Shaw; R. P. Woodward; F. W. Glaser; B. J. Dastoli

1977-01-01

338

Experimental investigation of a Mach 6 fixed-geometry inlet featuring a swept external-internal compression flow field  

NASA Technical Reports Server (NTRS)

An investigation of a fixed-geometry, swept external-internal compression inlet was conducted at a Mach number of 6.0 and a test-section Reynolds number of 1.55 x 10 to the 7th power per meter. The test conditions was constant for all runs with stagnation pressure and temperature at 20 atmospheres and 500 K, respectively. Tests were made at angles of attack of -5 deg, 0 deg, 3 deg, and 5 deg. Measurements consisted of pitot- and static-pressure surveys in inlet throat, wall static pressures, and surface temperatures. Boundary-layer bleed was provided on the centerbody and on the cowl internal surface. The inlet performance was consistently high over the range of the angle of attack tested, with an overall average total pressure recovery of 78 percent and corresponding adiabatic kinetic-energy efficiency of 99 percent. The inlet throat flow distribution was uniform and the Mach number and pressure level were of the correct magnitude for efficient combustor design. The utilization of a swept compression field to meet the starting requirements of a fixed-geometry inlet produced neither flow instability nor a tendency to unstart.

Torrence, M. G.

1975-01-01

339

HOTROD: a computer program for subchannel analysis of coolant flow in rod bundles (LWBR Development Program)  

Microsoft Academic Search

A digital computer program is described for the steady-state thermal and hydraulic subchannel analysis of coolant flow in rod bundle reactor cores and heated-rod experimental test sections. The program allows for the transfer of two-phase fluid properties in three dimensions and predicts the local fluid conditions, fuel rod surface temperature and critical heat flux. The history of subchannel analysis in

S. G. Beus; J. H. Anderson; R. J. DeCristofaro

1973-01-01

340

The Integral Vapor Compression and Liquid Coolant refrigeration system  

Microsoft Academic Search

The Integral Vapor Compression and Liquid (IVCL) coolant system developed by McDonnell Aircraft Company is described. The system operates on an innovative thermodynamic cycle that combines refrigeration and liquid coolant heat transport functions. Both analytical and empirical investigations show that the IVCL refrigeration system is technically feasible. When operating with low heat sink flow rates the performance coefficient of the

David L. Siems

1992-01-01

341

Coolant management critical in today's large diesel engines  

SciTech Connect

During the last decade, diesel engine manufacturers focused their research efforts on higher efficiencies and horse-power-to-weight ratios. The result was horsepower increases of between 20% and 30%. At the same time, coolant volume decreased by about the same amount. This has made coolant maintenance more important to ensure a long life for the engine and its cooling system.

Harrington, T. (Gold Fields Operating Co., Golconda, NV (US))

1991-01-01

342

Tidal inlet response to sediment infilling of the associated bay and possible implications of human activities: the Marennes-Oléron Bay and the Maumusson Inlet, France  

Microsoft Academic Search

Tidal inlet characteristics are controlled by wave energy, tidal range, tidal prism, sediment supply and direction and rates of sand delivered to the inlet. This paper deals with the relations between inlet and lagoon evolutions, linked by the tidal prism. Our study is focused on the Maumusson Inlet and the Marennes-Oléron Bay (first oyster farming area in Europe), located on

Xavier Bertin; Eric Chaumillon; Aldo Sottolichio; Rodrigo Pedreros

2005-01-01

343

A probabilistic method for determining effluent temperature limits for flow instability for SRS reactors  

SciTech Connect

This manual describes the uncertainty analysis used to determine the effluent temperature limits for a Mark 22 charge in the Savannah River Site production reactors. The postulated accident scenario is a DEGB/LOCA resulting from a coolant pipe break at the plenum inlet accompanied by the safety rod failure described in the previous chapter. The analysis described in this manual is used to calculate the limits for the flow instability phase of the accident. For this phase of the accident, the limits criterion is that the Stanton number does not exceed 0.00455 [1]. The limits are determined for a specified 84% probability that the Stanton number will not exceed 0.00455 in any assembly in the core.

Hardy, B.J.; White, A.M.

1990-06-01

344

Effects of rotation on coolant passage heat transfer. Volume 1: Coolant passages with smooth walls  

NASA Technical Reports Server (NTRS)

An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modern turbine blades. The immediate objective was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. Experiments were conducted in a smooth wall large scale heat transfer model.

Hajek, T. J.; Wagner, J. H.; Johnson, B. V.; Higgins, A. W.; Steuber, G. D.

1991-01-01

345

RELAP5/MOD1/029. LWR Loss of Coolant Analysis  

SciTech Connect

RELAP5 was developed to describe the behavior of a light water reactor (LWR) subjected to postulated transients such as loss of coolant from large or small pipe breaks, pump failures, etc. RELAP5 calculates fluid conditions such as velocities, pressures, densities, qualities, temperatures; thermal conditions such as surface temperatures, temperature distributions, heat fluxes; pump conditions; trip conditions; reactor power and reactivity from point reactor kinetics; and control system variables. In addition to reactor applications, the program can be applied to transient analysis of other thermal-hydraulic systems with water as the fluid.

Ransom, V.H. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1992-01-23

346

RELAP5/MOD1/025. LWR Loss of Coolant Analysis  

SciTech Connect

RELAP5 was developed to describe the behavior of a light water reactor (LWR) subjected to postulated transients such as loss of coolant from large or small pipe breaks, pump failures, etc. RELAP5 calculates fluid conditions such as velocities, pressures, densities, qualities, temperatures; thermal conditions such as surface temperatures, temperature distributions, heat fluxes; pump conditions; trip conditions; reactor power and reactivity from point reactor kinetics; and control system variables. In addition to reactor applications, the program can be applied to transient analysis of other thermal-hydraulic systems with water as the fluid.

Ransom, V.H. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1992-01-23

347

Liquid air as a coolant for thermal management of long-length HTS cable systems  

NASA Astrophysics Data System (ADS)

Direct current (dc), high temperature superconducting (HTS) cable systems have been suggested as an effective method of transmitting very large amounts of electric power (up to 10 GW) over very long distances (thousands of kilometers). This is made possible mainly by the high-current-carrying capability of the HTS materials when operated below their critical temperatures and by their near zero resistance to constant current. Most HTS cable concepts rely on liquid nitrogen or gaseous helium as the coolant. As an alternative, liquid air offers certain benefits and is discussed here as a cable system coolant. Air has a lower freezing temperature than nitrogen, it can be produced locally, and a liquid air leak will not displace the oxygen in a closed compartment. The dc cable design concept proposed by the Electric Power Research Institute (EPRI) in which the coolant flows in a cryogenic enclosure that includes the cable and a separate return tube, and refrigeration stations positioned every 10 to 20 km is assumed for this analysis. Both go and return lines are contained in a single vacuum envelope. The thermal management of this superconducting cable concept with liquid air in long-distance HTS power cables is developed in this paper. The results are compared to the use of liquid nitrogen, gaseous helium and gaseous hydrogen.

Demko, Jonathan; Hassenzahl, William

2012-06-01

348

Experimental Investigation of Forced Convection Heat Transfer of Nanofluids in a Microchannel using Temperature Nanosensors  

E-print Network

testing fluids were measured by varying the coolant flow rates, wall temperatures, nanoparticle material, nanoparticle morphology (shape and nanoparticle size) as well as mass concentrations of nanoparticles in the coolants. Anomalous thermal behavior...

Yu, Jiwon 1982-

2012-12-03

349

Silicon Microleaks for Inlets of Mass Spectrometers  

NASA Technical Reports Server (NTRS)

Microleaks for inlets of mass spectrometers used to analyze atmospheric gases can be fabricated in silicon wafers by means of photolithography, etching, and other techniques that are commonly used in the manufacture of integrated circuits and microelectromechanical systems. The microleaks serve to limit the flows of the gases into the mass-spectrometer vacuums to specified very small flow rates consistent with the capacities of the spectrometer vacuum pumps. There is a need to be able to precisely tailor the dimensions of each microleak so as to tailor its conductance to a precise low value. (As used here, "conductance" signifies the ratio between the rate of flow in the leak and the pressure drop from the upstream to the downstream end of the leak.) To date, microleaks have been made, variously, of crimped metal tubes, pulled glass tubes, or frits. Crimped-metal and pulled-glass-tube microleaks cannot readily be fabricated repeatably to precise dimensions and are susceptible to clogging with droplets or particles. Frits tend to be differentially chemically reactive with various gas constituents and, hence, to distort the gas mixtures to be analyzed. The present approach involving microfabrication in silicon largely overcomes the disadvantages of the prior approaches.

Harpold, Dan; Hasso, Niemann; Jamieson, Brian G.; Lynch, Bernard A.

2009-01-01

350

76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida  

Federal Register 2010, 2011, 2012, 2013, 2014

...Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida...continue to be managed as part of the Jupiter Inlet Lighthouse Outstanding Natural Area...U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural...

2011-05-02

351

Progress toward the analysis of supersonic inlet flows  

NASA Technical Reports Server (NTRS)

A zonal flow analysis procedure was developed to predict the flow through the supersonic diffuser of an axisymmetric mixed compression inlet at angle-of-attack. In this analysis, the inlet flow is divided into three types of regions, each with different dominant flow phenomena. These are the inviscid supersonic core, boundary layer, and shock/boundary layer interaction flows. An appropriate analysis was selected or developed for the three-dimensional flow in each type of region. Procedures were developed to interface these analyses for the overall inlet flow analysis. This analysis was applied to an inlet operating at M = 2.58 at several angle-of-attack conditions. Comparisons are presented between computed and measured flow properties for the inlet and for the component analysis flows. Extensions of the present procedure to include the terminal shock and subsonic diffuser flows are recommended. Desirable experiments for evaluation of the inlet analysis procedure or the component analyses and to support improved modeling or extension of the inlet analysis are defined and recommended.

Paynter, G. C.; Chen, H. C.

1983-01-01

352

Flow Simulation of Supersonic Inlet with Bypass Annular Duct  

NASA Technical Reports Server (NTRS)

A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.

Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.

2011-01-01

353

Unstart Coupling Mechanism Analysis of Multiple-Modules Hypersonic Inlet  

PubMed Central

The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted. PMID:24348146

Wang, Lei; Cao, Shibin

2013-01-01

354

Unstart coupling mechanism analysis of multiple-modules hypersonic inlet.  

PubMed

The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted. PMID:24348146

Hu, Jichao; Chang, Juntao; Wang, Lei; Cao, Shibin; Bao, Wen

2013-01-01

355

Aerodynamic design of a supersonic three-dimensional inlet  

NASA Astrophysics Data System (ADS)

The results of designing and numerical gas-dynamic modeling a supersonic three-dimensional inlet of a new type are considered. A ramp of external compression of this inlet is the V-shaped body forming an initial plane oblique shock wave and a subsequent isentropic compression wave. The inlet incorporates an entrance section of internal compression, where also a plane oblique shock wave and a subsequent isentropic compression wave are formed by a cowl. The designed three-dimensional inlet has small inclination angles of compression surfaces, which ensures its low wave drag. According to the estimates of inlet efficiency in terms of the compression ratio and the total pressure recovery factor, it is close to the optimal two-dimensional shocked inlet of external compression considered by Oswatisch as well as Petrov and Ukhov. The flow in the inlet was computed with the use of the Euler and Navier — Stokes codes provided by the commercial package “FLUENT”. The flow in the inlet throat in the design regime computed under the inviscid flow approximation is uniform. The most substantial effect of the flow viscosity in this regime manifests itself in the interaction of the shock wave from the cowl with the boundary layer on the V-shaped compression body in the inlet internal duct. According to computed data, the boundary layer separation does not occur in this case; however, due to viscosity effects, reflected shock waves are formed here which results in significant deviations of flow structure as compared to the computed inviscid flow.

Goonko, Yu. P.; Alexandrov, E. A.

2010-03-01

356

Observations of Currents in Two Tidally Modulated Inlets  

NASA Astrophysics Data System (ADS)

Observations of currents obtained in two tidally modulated inlets are used to examine the spatial evolution of the vertical structure in hourly averaged mean flow and at tidal frequencies. Field experiments of 30 day duration were conducted at Hampton/Seabrook Harbor, NH, in the Fall of 2011 and again at New River Inlet, NC, in the spring of 2012. The temporal variation and vertical structure of the currents were observed with 600 khz and 1200 khz RDI Acoustic Doppler Current Profilers (ADCP) deployed on low-profile bottom tripods just outside and within the inlet mouth, and with a Nortek Aquadopp Profiler mounted on a jetted pipe on the flank of the inlet channel. Across-inlet current profiles were obtained at each site at various tidal stages with a 1200 khz RDI vessel-mounted ADCP onboard the personal watercraft (the Coastal Bathymetry Survey System, or CBASS) that transited the inlet multiple times at various spatial locations. Flows within the inlet were dominated by semi-diurnal tides, ranging from 2.5 to 4 m in elevation at Hampton/Seabrook Harbor with velocities exceeding 3 m/s, and tides ranging from 1 to 1.5 m in elevation at New River Inlet with velocities exceeding 2 m/s. Flows sampled with the CBASS will be used to examine the horizontal and vertical variation in mean currents (averaged over about 20 - 40 min) at various tidal stages. Currents sampled with the fixed instruments will be used to examine the temporal variation in amplitude and direction of mean currents (averaged over 30 - 60 min) as a function of depth, as well as the amplitude, phase, and rotational structure at tidal frequencies. Observations from the two field sites will be compared and discussed in terms of the spatial and temporal evolution from outside the river mouth to the inner inlet channels over the fortnightly sampling period.

Lippmann, T. C.; Irish, J. D.; Hunt, J.

2012-12-01

357

Computational study of inlet injection for a Pre-Mixed, Shock-Induced Combustion (PM/SIC) engine  

NASA Technical Reports Server (NTRS)

A computational simulation of reacting 2-D and 3-D flowfields in a model inlet section of a Pre-Mixed, Shock-Induced Combustion (PM/SIC) engine concept was performed. LARCK, a multi-dimensional Navier-Stokes code with finite-rate kinetics chemistry developed at NASA LaRC by J.A. White, was adapted for this simulation. The flow conditions in the simulation match those envisioned for the PM/SIC engine experiments currently planned at LaRC. The reacting flowfields were Mach 6.3 freestream air and Mach 2 hydrogen at various pressure and temperature conditions injected through a slot injector at the base of the inlet section. In the PM/SIC engine, fuel is injected at the inlet section upstream of the combustor, and reaction is initiated by the shock wave at the inlet which increases the gas temperature and pressure beyond the kinetic limits for reaction. Many challenges exist prior to establishing shock-controlled combustion as a practical engine concept. These challenges include fuel injection schemes that can provide proper fuel-air mixing without creating large losses in the inlet section, and control of the combustion process so that early ignition or combustion propagation through the inlet boundary layer does not occur. For this project, a parametrics study was carried out to model the fuel injection of hydrogen at different flow conditions. It was found that, as the fuel temperature and pressure were increased, the potential for pre-ignition was high at a short distance downstream of the slot injector. The next stage of this work will investigate injection techniques for enhancing mixing of fuel and air in a manner that prevents or reduces the potential for premature ignition observed numerically.

Gonzalez, D. E.

1995-01-01

358

Cooling Air Inlet and Exit Geometries on Aircraft Engine Installations  

NASA Technical Reports Server (NTRS)

A semispan wing and nacelle of a typical general aviation twin-engine aircraft was tested to evaluate the cooling capability and drag or several nacelle shapes; the nacelle shapes included cooling air inlet and exit variations. The tests were conducted in the Ames Research Center 40 x 80-ft Wind Tunnel. It was found that the cooling air inlet geometry of opposed piston engine installations has a major effect on inlet pressure recovery, but only a minor effect on drag. Exit location showed large effect on drag, especially for those locations on the sides of the nacelle where the suction characteristics were based on interaction with the wing surface pressures.

Katz, Joseph; Corsiglia, Victor R.; Barlow, Philip R.

1982-01-01

359

Analysis of an advanced ducted propeller subsonic inlet  

NASA Technical Reports Server (NTRS)

It is shown that a time marching Navier-Stokes code called PARC can be utilized to provide a reasonable prediction of the flow field within an inlet for an advanced ducted propeller. The code validation was implemented for a nonseparated flow condition associated with the inlet functioning at angles-of-attack of zero and 25 deg. Comparison of the computational results with the test data shows that the PARC code with the propeller face fixed flow properties boundary conditions (BC) provided a better prediction of the inlet surface static pressures than the prediction when the mass flow BC was employed.

Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

1992-01-01

360

Variable geometry inlet design for scram jet engine  

NASA Technical Reports Server (NTRS)

The present invention relates to an improved variable geometry inlet for a scram jet engine having at least one combustor module. The variable geometry inlet comprises each combustor module having two sidewalls. Each of the sidewalls has a central portion with a thickness and a tapered profile forward of the central portion. The tapered profile terminates in a sharp leading edge. The variable geometry inlet further comprises each module having a lower wall and a movable cowl flap positioned forward of the lower wall. The movable cowl flap has a leading edge and the leading edges of the sidewalls intersect the leading edge of the cowl flap.

Guinan, Daniel P. (Inventor); Drake, Alan (Inventor); Andreadis, Dean (Inventor); Beckel, Stephen A. (Inventor)

2005-01-01

361

Numerical simulation of three-dimensional supersonic inlet flow fields  

NASA Technical Reports Server (NTRS)

Supersonic inlet flows with mixed external-internal compressions of an axisymmetric inlet model were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows typically found in supersonic inlets such as shock-wave intersections, flow spillage around the cowl lip, shock-wave/boundary-layer interactions, control of shock-induced flow separation by means of boundary layer bleed, internal normal (terminal) shocks, and the effects of flow incidence. Computed results were compared with available wind tunnel data.

Kawamura, T.; Chyu, W. J.; Bencze, D. P.

1987-01-01

362

A novel concept for subsonic inlet boundary-layer control  

NASA Technical Reports Server (NTRS)

A self-bleeding method for boundary layer control is described and tested for a subsonic inlet designed to operate in the flowfield generated by high angles of attack. Naturally occurring surface static pressure gradients are used to remove the boundary layer from a separation-prone region of the inlet and to reinject it at a less critical location with a net performance gain. The results suggest that this self-bleeding method for boundary-layer control might be successfully applied to other inlets operating at extreme aerodynamic conditions.

Miller, B. A.

1977-01-01

363

Estimation of additive forces and moments for supersonic inlets  

NASA Technical Reports Server (NTRS)

A technique for estimating the additive forces and moments associated with supersonic, external compression inlets as a function of mass flow ratio has been developed. The technique makes use of a low order supersonic paneling method for calculating minimum additive forces at maximum mass flow conditions. A linear relationship between the minimum additive forces and the maximum values for fully blocked flow is employed to obtain the additive forces at a specified mass flow ratio. The method is applicable to two-dimensional inlets at zero or nonzero angle of attack, and to axisymmetric inlets at zero angle of attack. Comparisons with limited available additive drag data indicate fair to good agreement.

Perkins, Stanley C., Jr.; Dillenius, Marnix F. E.

1991-01-01

364

Performance and boundary-layer evaluation of a sonic inlet  

NASA Technical Reports Server (NTRS)

Tests were conducted to determine the boundary layer characteristics and aerodynamic performance of a radial vane sonic inlet with a length/diameter ratio of 1 for several vane configurations. The sonic inlet was designed with a slight wavy wall type of diffuser geometry, which permits operation at high inlet Mach numbers (sufficiently high for good noise suppression) without boundary layer flow separation and with good total pressure recovery. A new method for evaluating the turbulent boundary layer was developed to separate the boundary layer from the inviscid core flow, which is characterized by a total pressure variation from hub to tip, and to determine the experimental boundary layer parameters.

Schmidt, J. F.; Ruggeri, R. S.

1976-01-01

365

Internal flow characteristics of a multistage compressor with inlet pressure distortion. [J85-13 turbojet engine studies  

NASA Technical Reports Server (NTRS)

The measured distribution of compressor interstage pressures and temperatures resulting from a 180 deg inlet-total-pressure distortion for a J85-13 turbojet engine is reported. Extensive inner stage instrumentation combined with stepwise rotation of the inlet distortion gave data of high circumferential resolution. The steady-state pressures and temperatures along with the amplitude, extent, and location of the distorted areas are given. Data for 80, 90, and 100 percent of rotor design speed are compared with clean (undistorted) inlet flow conditions to show pressure and temperature behavior within the compressor. Both overall and stagewise compressor performances vary only slightly when clean and distorted inlet conditions are compared. Total and static pressure distortions increase in amplitude in the first few stages of the compressor and then attenuate fairly uniformly to zero at the discharge. Total-temperature distortion induced by the pressure distortion reached a maximum amplitude by the first two stages and decayed only a little through the rest of the compressor. Distortion amplitude tended to peak in line with the screen edges, and, except for total and static pressure in the tip zone, there was little swirl in the axial direction.

Debogdan, C. E.; Moss, J. E., Jr.; Braithwaite, W. M.

1977-01-01

366

ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project  

NASA Technical Reports Server (NTRS)

The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate buffer concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. The remediation steps include changes in the coolant chemistry specification, development of a suite of new antimicrobial additives, and development of devices for the removal of nickel and phosphate ions from the coolant. This paper presents an overview of the anomalies, their known and suspected system effects, their causes, and the actions being taken to remediate the coolant.

Morrison, Russell H.; Holt, Mike

2005-01-01

367

Design of the coolant system for the Large Coil Test Facility pulse coils  

SciTech Connect

The pulse coils will be a part of the Large Coil Test Facility in Oak Ridge, Tennessee, which is designed to test six large tokamak-type superconducting coils. The pulse coil set consists of two resistive coaxial solenoid coils, mounted so that their magnetic axis is perpendicular to the toroidal field lines of the test coil. The pulse coils provide transient vertical fields at test coil locations to simulate the pulsed vertical fields present in tokamak devices. The pulse coils are designed to be pulsed for 30 s every 150 s, which results in a Joule heating of 116 kW per coil. In order to provide this capability, the pulse coil coolant system is required to deliver 6.3 L/s (100 gpm) of subcooled liquid nitrogen at 10-atm absolute pressure. The coolant system can also cool down each pulse coil from room temperature to liquid nitrogen temperature. This paper provides details of the pumping and heat exchange equipment designed for the coolant system and of the associated instrumentation and controls.

Bridgman, C.; Ryan, T.L.

1983-01-01

368

Unsteady Analysis of Inlet-Compressor Acoustic Interactions Using Coupled 3-D and 1-D CFD Codes  

NASA Technical Reports Server (NTRS)

It is well known that the dynamic response of a mixed compression supersonic inlet is very sensitive to the boundary condition imposed at the subsonic exit (engine face) of the inlet. In previous work, a 3-D computational fluid dynamics (CFD) inlet code (NPARC) was coupled at the engine face to a 3-D turbomachinery code (ADPAC) simulating an isolated rotor and the coupled simulation used to study the unsteady response of the inlet. The main problem with this approach is that the high fidelity turbomachinery simulation becomes prohibitively expensive as more stages are included in the simulation. In this paper, an alternative approach is explored, wherein the inlet code is coupled to a lesser fidelity 1-D transient compressor code (DYNTECC) which simulates the whole compressor. The specific application chosen for this evaluation is the collapsing bump experiment performed at the University of Cincinnati, wherein reflections of a large-amplitude acoustic pulse from a compressor were measured. The metrics for comparison are the pulse strength (time integral of the pulse amplitude) and wave form (shape). When the compressor is modeled by stage characteristics the computed strength is about ten percent greater than that for the experiment, but the wave shapes are in poor agreement. An alternate approach that uses a fixed rise in duct total pressure and temperature (so-called 'lossy' duct) to simulate a compressor gives good pulse shapes but the strength is about 30 percent low.

Suresh, A.; Cole, G. L.

2000-01-01

369

Corrosion problems with aqueous coolants, final report  

SciTech Connect

The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

Diegle, R B; Beavers, J A; Clifford, J E

1980-04-11

370

14 CFR 25.941 - Inlet, engine, and exhaust compatibility.  

Code of Federal Regulations, 2012 CFR

...variable inlet or exhaust system geometry, or both— (a) The system comprised of the...thrust augmentation systems, if incorporated...rotating speeds and power settings, and engine...configurations; (b) The dynamic effects of...

2012-01-01

371

14 CFR 25.941 - Inlet, engine, and exhaust compatibility.  

Code of Federal Regulations, 2011 CFR

...variable inlet or exhaust system geometry, or both— (a) The system comprised of the...thrust augmentation systems, if incorporated...rotating speeds and power settings, and engine...configurations; (b) The dynamic effects of...

2011-01-01

372

Theoretical Investigation of Submerged Inlets at Low Speeds  

NASA Technical Reports Server (NTRS)

The general characteristics of the flow field in a submerged air inlet are investigated by theoretical, wind-tunnel, and visual-flow studies. Equations are developed for calculating the laminar and turbulent boundary-layer growth along the ramp floor for parallel, divergent, and convergent ramp walls, and a general equation is derived relating the boundary-layer pressure losses to the boundary-layer thickness. It is demonstrated that the growth of the boundary layer on the floor of the divergent-ramp inlet is retarded and that a vortex pair is generated in such an inlet. Functional relationships are established between the pressure losses in the vortices and the geometry of the inlet. A general discussion of the boundary layer and vortex formations is included, in which variations of the various losses and of the incremental external drag with mass-flow ratio are considered. Effects of compressibility are also discussed.

Sacks, Alvin H.; Spreiter, John R.

1951-01-01

373

33 CFR 334.1250 - Carr Inlet, naval restricted areas.  

Code of Federal Regulations, 2012 CFR

...line perpendicular to the course line opposite Ketner's Point, and about one mile from...or electric drive to a propeller, pump jet, paddle wheel or other device), and...hydrophone buoys situated in Carr Inlet opposite Ketner's Point; provided,...

2012-07-01

374

33 CFR 334.1250 - Carr Inlet, naval restricted areas.  

Code of Federal Regulations, 2013 CFR

...line perpendicular to the course line opposite Ketner's Point, and about one mile from...or electric drive to a propeller, pump jet, paddle wheel or other device), and...hydrophone buoys situated in Carr Inlet opposite Ketner's Point; provided,...

2013-07-01

375

33 CFR 334.1250 - Carr Inlet, naval restricted areas.  

Code of Federal Regulations, 2011 CFR

...line perpendicular to the course line opposite Ketner's Point, and about one mile from...or electric drive to a propeller, pump jet, paddle wheel or other device), and...hydrophone buoys situated in Carr Inlet opposite Ketner's Point; provided,...

2011-07-01

376

33 CFR 334.1250 - Carr Inlet, naval restricted areas.  

Code of Federal Regulations, 2014 CFR

...line perpendicular to the course line opposite Ketner's Point, and about one mile from...or electric drive to a propeller, pump jet, paddle wheel or other device), and...hydrophone buoys situated in Carr Inlet opposite Ketner's Point; provided,...

2014-07-01

377

CFD Results for an Axisymmetric Isentropic Relaxed Compression Inlet  

NASA Technical Reports Server (NTRS)

The OVERFLOW code was used to calculate the flow field for a family of five relaxed compression inlets, which were part of a screening study to determine a configuration most suited to the application of microscale flow control technology as a replacement for bleed. Comparisons are made to experimental data collected for each of the inlets in the 1- by 1-Foot Supersonic Wind Tunnel at the NASA Glenn Research Center (GRC) to help determine the suitability of computational fluid dynamics (CFD) as a tool for future studies of these inlets with flow control devices. Effects on the wind tunnel results of the struts present in a high subsonic flow region accounted for most of the inconsistency between the results. Based on the level of agreement in the present study, it is expected that CFD can be used as a tool to aid in the design of a study of this class of inlets with flow control.

Hirt, Stefanie M.; Tacina, Kathleen M.; Conners, Timothy R.; Merret, Jason M.; Howe, Donald C.

2008-01-01

378

46 CFR 42.15-60 - Scuppers, inlets, and discharges.  

Code of Federal Regulations, 2011 CFR

...15-60 Scuppers, inlets, and discharges. (a) Discharges led through the shell either from spaces below the freeboard...doors complying with the requirements of § 42.15-10 shall be led overboard. (e) All valves and shell fittings...

2011-10-01

379

46 CFR 42.15-60 - Scuppers, inlets, and discharges.  

Code of Federal Regulations, 2010 CFR

...15-60 Scuppers, inlets, and discharges. (a) Discharges led through the shell either from spaces below the freeboard...doors complying with the requirements of § 42.15-10 shall be led overboard. (e) All valves and shell fittings...

2010-10-01

380

46 CFR 42.15-60 - Scuppers, inlets, and discharges.  

Code of Federal Regulations, 2012 CFR

...15-60 Scuppers, inlets, and discharges. (a) Discharges led through the shell either from spaces below the freeboard...doors complying with the requirements of § 42.15-10 shall be led overboard. (e) All valves and shell fittings...

2012-10-01

381

46 CFR 42.15-60 - Scuppers, inlets, and discharges.  

Code of Federal Regulations, 2013 CFR

...15-60 Scuppers, inlets, and discharges. (a) Discharges led through the shell either from spaces below the freeboard...doors complying with the requirements of § 42.15-10 shall be led overboard. (e) All valves and shell fittings...

2013-10-01

382

Metals Verification Study for Sinclair and Dyes Inlets,Washington  

SciTech Connect

Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington's 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. This Metals Verification Study was conducted to address the 303(d) segments that are listed for metal contaminants in marine sediment, because significant cleanup and source control activities have been conducted in the Inlets since the data supporting the 1998 303(d) listings were collected. The study was designed to obtain present-day sediment metals concentrations throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, with stations spatially distributed to support 303(d) listing updates and also watershed-level water quality and contaminant transport modeling efforts. A total of 160 surface sediment samples from Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage were screened for copper, lead, and zinc using X-Ray Fluorescence (XRF). 40 samples (25%) were selected for confirmatory metals analysis by ICP-MS for cadmium, silver, and arsenic in addition to copper, lead, and zinc. Regression relationships between the ICP-MS and XRF datasets were developed to estimate copper, lead, and zinc concentrations in all samples. The XRF results for copper, lead, and zinc correlated well with ICP-MS results, and predicted concentrations were calculated for all samples. The results of the Metals Verification Study show that sediment quality in Sinclair Inlet has improved markedly since implementation of cleanup and source control actions, and that the distribution of residual contaminants is limited to nearshore areas already within the actively managed Puget Sound Naval Shipyard Superfund Site where further source control actions and monitoring are under way. Outside of Sinclair Inlet, the target metals met state sediment quality standards.

Kohn, Nancy P.; Miller, Martin C.; Brandenberger, Jill M.; Johnston, Robert K.

2004-09-29

383

A multiobjective shape optimization study for a subsonic submerged inlet  

NASA Astrophysics Data System (ADS)

The purpose of the present work is to summarize the findings of a multiobjective shape optimization study conducted for a subsonic submerged air vehicle inlet. The objective functions of the optimization problem are distortion and swirl indices defined by the distribution of flow parameters over the exit cross-section of the inlet. The geometry alteration is performed by placing a protrusion in the shape of a fin on the baseline inlet surface. Thus, the design variables of the optimization problem are chosen to be the geometrical parameters defining the fin protrusion; namely fin height, length and incidence angle. The Trade Off (also known as epsilon-constraint) method is employed for finding the Pareto optimal set formed by the nondominated solutions of the feasible design space. Since the flow domain solution is required for every step along the line search, an automated optimization loop is constructed by integrating the optimizer with a surface modeler, a mesh generator and a flow solver through which the flow parameters over the compressor face are computed. In addition, the trade study for fin protrusion, the analyses and the comparison of the baseline and Pareto optimal solutions are presented and observations concerning grid resolution and convergence behaviour are discussed. The results display an irregular and discontinuous Pareto optimal set. Optimum inlet designs are scattered in two regions from which one representative inlet design is chosen and analyzed. As a result, it is concluded that an inlet designer has two options within the framework of this optimization study: an inlet design with high swirl but low distortion or an inlet design with low swirl but higher distortion.

Taskinoglu, Ezgi S.

384

Underwater maintenance and inspection of CP systems (Cook Inlet, Alaska)  

SciTech Connect

About 15 offshore oil and gas platforms, as well as several docks and loading platforms, are located at Cook Inlet, Alaska. Platforms and loading facilities are connected by a network of subsea pipelines. Practical methods for inspecting and maintaining the cathodic protection systems on Cook Inlet offshore structures are reviewed. Factors that make the location unique are explained, and the limitations of the inspection techniques are discussed.

Daley, J.C.; Ingraham, D. [American Divers, Anchorage, AK (United States)

1996-01-01

385

A flux-split solution procedure for unsteady inlet flows  

NASA Technical Reports Server (NTRS)

The unstart and restart of an axisymmetric inlet is investigated using a flux-split procedure applied to the Euler and Reduced Navier Stokes (RNS) equations. A time consistent direct sparse matrix solver is applied to compute the transient flow field both internal and external to the inlet. Time varying oblique and normal shocks are captured. The code is quite general and is applicable for subsonic, transonic and supersonic free streams. The current analysis is concerned with supersonic flight conditions.

Pordal, H. S.; Khosla, P. K.; Rubin, S. G.

1990-01-01

386

Modelling of the Gold Coast Seaway tidal inlet, Australia  

Microsoft Academic Search

SENNES, G., CASTELLE, B., BERTIN, X., MIRFENDERESK, H. AND TOMLINSON, R.B., 2007. Modelling of the Gold Coast Seaway tidal inlet, Australia. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1086 - 1091. Gold Coast, Australia, ISSN 0749.0208 The Seaway entrance is a tidal inlet located on the Gold Coast (Queensland, Australia). Before the 80s, the

G. Sennes; B. Castelle; X. Bertin; H. Mirfenderesk; R. B. Tomlinson

2007-01-01

387

A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems  

NASA Technical Reports Server (NTRS)

This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H20 for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

Mason, Lee S.; Siamidis, John

2006-01-01

388

A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems  

NASA Astrophysics Data System (ADS)

This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

Siamidis, John; Mason, Lee

2006-01-01

389

Mach 4 Test Results of a Dual-Flowpath, Turbine Based Combined Cycle Inlet  

NASA Technical Reports Server (NTRS)

An experimental study was conducted to evaluate the performance of a turbine based combined cycle (TBCC) inlet concept, consisting of a low speed turbojet inlet and high speed dual-mode scramjet inlet. The main objectives of the study were (1) to identify any interactions between the low and the high speed inlets during the mode transition phase in which both inlets are operating simultaneously and (2) to determine the effect of the low speed inlet operation on the performance of the high speed inlet. Tests were conducted at a nominal freestream Mach number of 4 using an 8 percent scale model representing a single module of a TBCC inlet. A flat plate was installed upstream of the model to produce a turbulent boundary layer which simulated the full-scale vehicle forebody boundary layer. A flowmeter/back pressure device, with remote actuation, was attached aft of the high speed inlet isolator to simulate the back pressure resulting from dual-mode scramjet combustion. Results indicate that the inlets did not interact with each other sufficiently to affect inlet operability. Flow spillage resulting from a high speed inlet unstart did not propagate far enough upstream to affect the low speed inlet. Also, a low speed inlet unstart did not cause the high speed inlet to unstart. The low speed inlet improved the performance of the high speed inlet at certain conditions by diverting a portion of the boundary layer generated on the forebody plate.

Albertson, Cindy w.; Emami, Saied; Trexler, Carl A.

2006-01-01

390

Numerical Investigation of Actuators for Flow Control in Inlet Ducts  

NASA Astrophysics Data System (ADS)

For military applications, inlet designs are constrained by low observability requirements, which call for the use of an S-duct inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the aircraft. For this reason, aggressive inlets can have a large impact on overall system efficiency. Numerical simulations have been carried out which evaluate the effectiveness of steady and unsteady actuation for active flow control in an aggressive S-duct inlet, L/D = 1.5 (at flow conditions representative of flight conditions). These simulations were performed in close co-ordination with the experiments to be able to validate CFD predictions and further provide a complementary and detailed view of the flow field. Comparisons will be made between: steady and unsteady blowing from a single 2-D tangential slit. Evaluations criteria will include total pressure recovery, AIP distortion levels, and unsteady pressure fluctuations. It is noteworthy to mention that the agreement between the CFD predictions and the experimental measurements were found to be very good.

Jansen, Kenneth; Sahni, Onkar; Amitay, Michael

2009-11-01

391

Euler flow in a supersonic mixed-compression inlet  

NASA Astrophysics Data System (ADS)

Numerical simulation of a two-dimensional mixed compression supersonic inlet is carried out by solving unsteady compressible Euler equations via a stabilized finite element method. The geometry of the inlet is similar to the one used by Anderson and Wong for experimental investigation for Mach 3 flow. The computations are capable of simulating the start-up problems associated with the inlet. The critical back pressure for the successful operation of the inlet is computed. The effect of inlet back pressure on the total pressure recovery and the flow distortion level is analysed. Contrary to the popular belief, it is found that in addition to the throat to inlet capture area ratio, the ramp geometry close to the throat plays an important role in the start-up dynamics. It is demonstrated via simulations that, everything else being same, the geometries of ramp upstream of the throat that are associated with a curvature higher than a certain threshold, result in unstarting the intake.

Jain, Manish Kumar; Mittal, Sanjay

2006-04-01

392

Experimental Investigation of Actuators for Flow Control in Inlet Ducts  

NASA Astrophysics Data System (ADS)

Attractive to aircraft designers are compact inlets, which implement curved flow paths to the compressor face. These curved flow paths could be employed for multiple reasons. One of which is to connect the air intake to the engine embedded in the aircraft body. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic purpose of inlets is to decelerate the oncoming flow before reaching the engine while minimizing total pressure loss, unsteadiness and distortion. Low length-to-diameter ratio inlets have a high degree of curvature, which inevitably causes flow separation and secondary flows. Currently, the length of the propulsion system is constraining the overall size of Unmanned Air Vehicles (UAVs), thus, smaller more efficient aircrafts could be realized if the propulsion system could be shortened. Therefore, active flow control is studied in a compact (L/D=1.5) inlet to improve performance metrics. Actuation from a spanwise varying coanda type ejector actuator and a hybrid coanda type ejector / vortex generator jet actuator is investigated. Special attention will be given to the pressure recovery at the AIP along with unsteady pressure signatures along the inlet surface and at the AIP.

Vaccaro, John; Elimelech, Yossef; Amitay, Michael

2010-11-01

393

Experimental Investigation of Actuators for Flow Control in Inlet Ducts  

NASA Astrophysics Data System (ADS)

For military applications, inlet designs are constrained by low observability requirements, which call for the use of an S-duct inlet. The inlets purpose is to limit the line-of-sight to the compressor and decelerate the incoming flow while minimizing total pressure loss, distortion, and unsteadiness. In addition, in unmanned aerial vehicles, the inlet length can determine the overall size of the aircraft. For this reason, aggressive inlets can have a large impact on overall system efficiency. Experiments have been conducted which evaluate the effectiveness of different actuation systems for active flow control in an aggressive S-duct inlet, L/D = 1.5 (at flow conditions representative of flight conditions). Comparisons will be made between: steady and unsteady blowing from a single 2-D tangential slit, spanwise varying injection from a tangential slit, and spanwise varying injection of a hybrid actuator that has both a coanda type injector along with vortex generator jets to eliminate vorticity developed by secondary flow inherent to S-ducts. Evaluations criteria will include total pressure recovery, AIP distortion levels, and unsteady pressure fluctuations.

Vaccaro, John; Amitay, Michael

2009-11-01

394

Large-Scale Low-Boom Inlet Test Overview  

NASA Technical Reports Server (NTRS)

This presentation provides a high level overview of the Large-Scale Low-Boom Inlet Test and was presented at the Fundamental Aeronautics 2011 Technical Conference. In October 2010 a low-boom supersonic inlet concept with flow control was tested in the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). The primary objectives of the test were to evaluate the inlet stability and operability of a large-scale low-boom supersonic inlet concept by acquiring performance and flowfield validation data, as well as evaluate simple, passive, bleedless inlet boundary layer control options. During this effort two models were tested: a dual stream inlet intended to model potential flight hardware and a single stream design to study a zero-degree external cowl angle and to permit surface flow visualization of the vortex generator flow control on the internal centerbody surface. The tests were conducted by a team of researchers from NASA GRC, Gulfstream Aerospace Corporation, University of Illinois at Urbana-Champaign, and the University of Virginia

Hirt, Stefanie

2011-01-01

395

TBCC Engine Inlet Design and Ramp Angle Optimization  

NASA Astrophysics Data System (ADS)

Mixed-compression hypersonic inlet for the combined cycle engine is designed based on aerodynamic theory and Oswatitsch best shock wave theory. Its performances are obtained using CFD (Computational Fluid Dynamics) technology. Firstly, an aircraft flight trajectory is selected with its cruise condition fixed as inlet design point. Along flight trajectory, the dynamic pressure is kept constant. There are two critical points which divide the whole take-off process into three steps: only the turbo engine operation, turbo and ram combined operation, and only the ram engine operation. Secondly, two dimensional inlet design: the inlet is divided into three parts; namely, external compression part, internal compression parts and throat. The three external compression shocks have the same shock intensity and interact on cowl lip. Flow direction turns three times and before entering the throat, flow direction is in accord with the forth coming flow. Inlet throat cross section area keeps constant. The existence of boundary layer leads to reduction of flux. Therefore, the designed inlet geometry should be modified. The CFD results show that geometry modification decreases cowl lip spillage.

Zhang, J. D.; Cai, Y. H.; Wang, Z. X.

396

Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems  

NASA Technical Reports Server (NTRS)

Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

2011-01-01

397

Effect of variable inlet guide vanes on the operating characteristics of a tilt nacelle inlet/powered fan model  

NASA Technical Reports Server (NTRS)

The effects of a variable inlet guide vane (VIGV) assembly on the operating characteristics of a V/STOL inlet and on the performance of a 20-in. (0.508-m) diameter fan engine were investigated. The data indicate that the VIGVs are effective thrust modulators over a wide range of free-stream velocities, nacelle angles of attack, and fan speeds. The thrust modulation ranges, including choking limits, fan stall limits, and inlet separation boundaries are presented. The presence of the VIGV assembly causes significant losses in inlet angle-of-attack capability and generally increases the blade stress levels at all limit conditions except at high angle of attack and high free-stream velocity. Reducing the fan nozzle exit area limited the positive VIGV actuation range and consequently decreased the range of thrust modulation at all limit conditions except at both high free-stream velocity and high angle of attack conditions.

Woollett, R. R.; Pontonides, H. C.

1987-01-01

398

An Experimental Investigation of NACA Submerged Inlets at High Subsonic Speeds I: Inlets Forward of the Wing Leading Edge  

NASA Technical Reports Server (NTRS)

This report covers the first part of an experimental investigation of NACA submerged inlets at four locations on the fuselage of a fighter airplane model for Mach numbers from 0.30 to 0.875. Data are presented showing the characteristics of the model without inlets and with inlets 16.7 percent of the root chord forward of the wing-root leading edge and equipped with small boundary-layer deflectors. The data show that variations in the mass of air entering the inlet had a large effect on the ram-recovery ratio. Representative values of ram-recovery ratio were 0.50 with zero flow, 0.90 with 0.6 mass-flow coefficient, and 0.95 with 1.00 mass-flow coefficient. Variations in Mach number and angle of attack, in general, caused less than a 0.03 variation in the ram-recovery ratio.

Hall, Charles F; Barclay, F Dorn

1948-01-01

399

Application of rotor mounted pressure transducers to analysis of inlet turbulence. [flow distortion in turbofan engine inlet  

NASA Technical Reports Server (NTRS)

Miniature pressure transducers installed near the leading edge of a fan blade were used to diagnose the non-uniform flow entering a subsonic tip speed turbofan on a static test stand. The pressure response of the blade to the inlet flow variations was plotted in a form which shows the space-time history of disturbances ingested by the rotor. Also, periodically sampled data values were auto- and cross-correlated as if they had been acquired from fixed hot wire anemometers at 150 equally spaced angles around the inlet. With a clean inlet and low wind, evidence of long, narrow turbulence eddies was easily found both in the boundary layer of the fan duct and outside the boundary layer. The role of the boundary layer was to follow and amplify disturbances in the outer flow. These eddies frequently moved around the inlet with a corkscrew motion as they passed through.

Hanson, D. B.

1976-01-01

400

High-temperature turbine technology program hot-gas path development test. Part II. Testing  

SciTech Connect

This topical report of the US Department of Energy High-Temperature Turbine Technology (DOE-HTTT) Phase II program presents the results of testing full-scale water-cooled first-stage and second-stage turbine nozzles at design temperature and pressure to verify that the designs are adequate for operation in a full-scale turbine environment. Low-cycle fatigue life of the nozzles was demonstrated by subjecting cascade assemblies to several hundred simulated startup/shutdown turbine cycles. This testing was accomplished in the Hot-Gas Path Development Test Stand (HGPDTS), which is capable of evaluating full-scale combustion and turbine nozzle components. A three-throat cascade of the first-stage turbine nozzle was successfully tested at a nozzle inlet gas temperature of 2630/sup 0/F and a nozzle inlet pressure of 11.3 atmospheres. In addition to steady-state operation at the design firing temperature, the nozzle cascade was exposed to a simulated startup/shutdown turbine cycle by varying the firing temperature. A total of 42 h at the design point and 617 thermal cycles were accumulated during the test periods. First-stage nozzle test results show that measured metal and coolant temperatures correspond well to the predicted design values. This nozzle design has been shown to be fully satisfactory for the application (2600/sup 0/F), with growth capability to 3000/sup 0/F firing temperature. A post-test metallurgical examination of sectioned portions of the tested nozzles shows a totally bonded structure, confirming the test results and attesting to the successful performance of water-cooled composite nozzle hardware.

Horner, M.W.

1982-03-01

401

INVESTIGATION OF CLEANER TECHNOLOGIES TO MINIMIZE AUTOMOTIVE COOLANT WASTES  

EPA Science Inventory

The US Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction and econo...

402

Transient two-phase performance of LOFT reactor coolant pumps  

SciTech Connect

Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed.

Chen, T.H.; Modro, S.M.

1983-01-01

403

EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT  

EPA Science Inventory

This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive engine coolants at a New Jersey Department of Transportation garage. he specific recycling units evaluated are based on the technologies of filtration and distilla...

404

Optimized Coolant-Flow Diverter For Increased Bearing Life  

NASA Technical Reports Server (NTRS)

Coolant-flow diverter for rolling-element bearings in cryogenic turbopump designed to enhance cooling power of flow in contact with bearings and thereby reduce bearing wear. Delivers jets of coolant as close as possible to hot spots at points of contact between balls and race. Also imparts swirl that enhances beneficial pumping effect. Used with success in end ball bearing of high-pressure-oxidizer turbopump.

Subbaraman, Maria R.; Butner, Myles F.

1995-01-01

405

Analysis of an advanced ducted propeller subsonic inlet  

NASA Technical Reports Server (NTRS)

A time marching Navier-Stokes code called PARC (PARC2D for 2-D/axisymmetric and PARC3D for 3-D flow simulations) was validated for an advanced ducted propeller (ADP) subsonic inlet. The code validation for an advanced ducted propeller (ADP) subsonic inlet. The code validation was implemented for a non-separated flow condition associated with the inlet operating at angles-of-attack of 0 and 25 degrees. The inlet test data were obtained in the 9 x 15 ft Low Speed Wind Tunnel at NASA Lewis Research Center as part of a cooperative study with Pratt and Whitney. The experimental study focused on the ADP inlet performance for take-off and approach conditions. The inlet was tested at a free stream Mach number of 0.2, at angles-of-attack between O and 35 degrees, and at a maximum propeller speed of 12,000 RPM which induced a corrected air flow rate of about 46 lb/sec based on standard day conditions. The computational grid and flow boundary conditions (BC) were based on the actual inlet geometry and the funnel flow conditions. At the propeller face, two types of BC's were applied: a mass flow BC and a fixed flow properties BC. The fixed flow properties BC was based on a combination of data obtained from the experiment and calculations using a potential flow code. Comparison of the computational results with the test data indicates that the PARC code with the propeller face fixed flow properties BC provided a better prediction of the inlet surface static pressures than the predictions when the mass flow BC was used. For an angle-of-attack of 0 degrees, the PARC2D code with the propeller face mass flow BC provided a good prediction of inlet static pressures except in the region of high pressure gradient. With the propeller face fixed flow properties BC, the PARC2D code provided a good prediction of the inlet static pressures. For an angle-of-attack of 25 degrees with the mass flow BC, the PARC3D code predicted statis pressures which deviated significantly from the test data; however, with the fixed flow properties BC, a good comparison with the test data was obtained.

Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

1992-01-01

406

PACER -- A fast running computer code for the calculation of short-term containment/confinement loads following coolant boundary failure. Volume 1: Code models and correlations  

SciTech Connect

A fast running and simple computer code has been developed to calculate pressure loadings inside light water reactor containments/confinements under loss-of-coolant accident conditions. PACER was originally developed to calculate containment/confinement pressure and temperature time histories for loss-of-coolant accidents in Soviet-designed VVER reactors and is relevant to the activities of the US International Nuclear Safety Center. The code employs a multicompartment representation of the containment volume and is focused upon application to early time containment phenomena during and immediately following blowdown. Flashing from coolant release, condensation heat transfer, intercompartment transport, and engineered safety features are described using best estimate models and correlations often based upon experiment analyses. Two notable capabilities of PACER that differ from most other containment loads codes are the modeling of the rates of steam and water formation accompanying coolant release as well as the correlations for steam condensation upon structure.

Sienicki, J.J.

1997-06-01

407

Analysis of thrust augmentation of turbojet engines by water injection at compressor inlet including charts for calculating compression processes with water injection  

NASA Technical Reports Server (NTRS)

A psychrometric chart having total pressure (sum of partial pressures of air and water vapor) as a variable, a Mollier diagram for air saturated with water vapor, and charts showing the thermodynamic properties of various air-water vapor and exhaust gas-water vapor mixtures are presented as aids in calculating the thrust augmentation of a turbojet engine resulting from the injection of water at the compressor inlet. Curves are presented that show the theoretical performance of the augmentation method for various amounts of water injected and the effects of varying flight Mach number, altitude, ambient-air temperature, ambient relative humidity, compressor pressure ratio, and inlet-diffuser efficiency. Numerical examples, illustrating the use of the psychrometric chart and the Mollier diagram in calculating both compressor-inlet and compressor-outlet conditions when water is injected at the compressor inlet, are presented.

Wilcox, E Clinton; Trout, Arthur M

1951-01-01

408

Demonstrated survivability of a high temperature optical fiber cable on a 1500 pound thrust rocket chamber  

NASA Technical Reports Server (NTRS)

A demonstration of the ability of an existing optical fiber cable to survive the harsh environment of a rocket engine was performed at the NASA Lewis Research Center. The intent of this demonstration was to prove the feasibility of applying fiber optic technology to rocket engine instrumentation systems. Extreme thermal transient tests were achieved by wrapping a high temperature optical fiber, which was cablized for mechanical robustness, around the combustion chamber outside wall of a 1500 lb Hydrogen-Oxygen rocket engine. Additionally, the fiber was wrapped around coolant inlet pipes which were subject to near liquid hydrogen temperatures. Light from an LED was sent through the multimode fiber, and output power was monitored as a function of time while the engine was fired. The fiber showed no mechanical damage after 419 firings during which it was subject to transients from 30 K to 350 K, and total exposure time to near liquid hydrogen temperatures in excess of 990 seconds. These extreme temperatures did cause attenuation greater than 3 dB, but the signal was fully recovered at room temperature. This experiment demonstrates that commercially available optical fiber cables can survive the environment seen by a typical rocket engine instrumentation system, and disclose a temperature-dependent attenuation observed during exposure to near liquid hydrogen temperatures.

Sovie, Amy L.

1992-01-01

409

Response of a turbofan engine compression system to disturbed inlet conditions  

SciTech Connect

A generic code DYNTECC has been adapted to perform a parametric study of the effect of inlet flow distortion on the stability of the Pratt and Whitney TF30 engine. This code was developed at Arnold Engineering Development Center, USA, for single and dual spool systems. It was modified at AMRL to accommodate the particular geometry of the TF30 engine. The stage characteristics needed to operate DYNTECC were derived from experimental data for the fan and low-pressure compressor. For the high-pressure compressor they were derived using the STGSTK code developed at NASA Lewis Research Center. This program was modified at AMRL to include real flow effects that were in turn derived using yet another adapted code, CASCAD. The code was primarily used at AMRL to predict the onset of system instability due to simulated full-face rapid inlet temperature ramps typical of those caused during armament firings. It was also run with sinusoidal total pressure oscillations of varying amplitudes and frequencies at the inlet. The code predictions were compared with available data whenever possible, and were found to be consistent with the observed experimental trends.

Abdel-Fattah, A.M. [Defense Science and Technology Organisation, Melbourne (Australia). Aeronautical and Maritime Research Lab.

1997-10-01

410

Numerical Analysis of the Trailblazer Inlet Flowfield for Hypersonic Mach Numbers  

NASA Technical Reports Server (NTRS)

A study of the Trailblazer vehicle inlet was conducted using the Global Air Sampling Program (GASP) code for flight Mach numbers ranging from 4-12. Both perfect gas and finite rate chemical analysis were performed with the intention of making detailed comparisons between the two results. Inlet performance was assessed using total pressure recovery and kinetic energy efficiency. These assessments were based upon a one-dimensional stream-thrust-average of the axisymmetric flowfield. Flow visualization utilized to examine the detailed shock structures internal to this mixed-compression inlet. Kinetic energy efficiency appeared to be the least sensitive to differences between the perfect gas and finite rate chemistry results. Total pressure recovery appeared to be the most sensitive discriminator between the perfect gas and finite rate chemistry results for flight Mach numbers above Mach 6. Adiabatic wall temperature was consistently overpredicted by the perfect gas model for flight Mach numbers above Mach 4. The predicted shock structures were noticeably different for Mach numbers from 6-12. At Mach 4, the perfect gas and finite rate chemistry models collapse to the same result.

Steffen, C. J., Jr.; DeBonis, J. R.

1999-01-01

411

FLOW SEPARATION WITHIN THE ENGINE INLET OF AN UNINHABITED COMBAT AIR VEHICLE (UCAV)  

Microsoft Academic Search

This paper discusses the structure of the flow within the engine inlet of an uninhabited combat air vehicle (UCAV). The UCAV features a top-mounted, serpentine inlet leading to an engine buried within the fuselage. The performance of the inlet is found to depend strongly on a flow separation that occurs within the inlet. Both the time-averaged and the unsteady structure

Michael J. Brear; Zachary Warfield; John F. Mangus; Steve Braddom; James D. Paduano; Jeffry S. Philhower

2003-01-01

412

Double Ducted Fan (DDF) as a Novel Ducted Fan Inlet Lip Separation Control Device  

E-print Network

or minimal inlet flow distortion. The DDF concept is proven to be an effective way of dealing with inlet flowDouble Ducted Fan (DDF) as a Novel Ducted Fan Inlet Lip Separation Control Device Ali Akturk computational study of a novel ducted fan inlet flow conditioning concept that will significantly improve

Camci, Cengiz

413

CFD application to supersonic/hypersonic inlet airframe integration. [computational fluid dynamics (CFD)  

NASA Technical Reports Server (NTRS)

Supersonic external compression inlets are introduced, and the computational fluid dynamics (CFD) codes and tests needed to study flow associated with these inlets are outlined. Normal shock wave turbulent boundary layer interaction is discussed. Boundary layer control is considered. Glancing sidewall shock interaction is treated. The CFD validation of hypersonic inlet configurations is explained. Scramjet inlet modules are shown.

Benson, Thomas J.

1988-01-01

414

Distribution and Abundance of Larval Fishes at Two North Carolina Inlets  

NASA Astrophysics Data System (ADS)

Two major barrier island inlets that connect Pamlico Sound with the Atlantic Ocean were quantitatively sampled for larvae at new moon monthly intervals during 1988-89. Simultaneous tows of bottom and surface 1 m, 500 micron mesh nets were made day and night at single stations inside of Oregon Inlet and Ocracoke Inlet. Oregon Inlet, located in a more temperate marine province, was expected to have a different taxonomic community than Ocracoke Inlet, but, of 77 taxa collected from both inlets, 54 occurred at both inlets. Clupeoids and sciaenids were the dominant taxa in both inlets. At Oregon Inlet the lowest abundance of larvae occurred in February and the highest occurred in late August, whereas at Ocracoke Inlet, November and June were the lowest and highest months of larval abundance. At Oregon Inlet, 63% of the total number of larvae were caught near the bottom, but at Ocracoke Inlet, only 38% were caught near the bottom. Atlantic menhaden, Brevoortia tyrannus, were 40 times more abundant at the surface than at the bottom at Ocracoke Inlet. Most larvae were caught at night at both inlets. The times of occurrence and peak abundance for most species did not appear linked between inlets. Twenty-one species were significantly different in mean length between the two inlets.

Hettler, W. F.; Barker, D. L.

1993-08-01

415

Organics Verification Study for Sinclair and Dyes Inlets, Washington  

SciTech Connect

Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. Because significant cleanup and source control activities have been conducted in the inlets since the data supporting the 1998 303(d) listings were collected, two verification studies were performed to address the 303(d) segments that were listed for metal and organic contaminants in marine sediment. The Metals Verification Study (MVS) was conducted in 2003; the final report, Metals Verification Study for Sinclair and Dyes Inlets, Washington, was published in March 2004 (Kohn et al. 2004). This report describes the Organics Verification Study that was conducted in 2005. The study approach was similar to the MVS in that many surface sediment samples were screened for the major classes of organic contaminants, and then the screening results and other available data were used to select a subset of samples for quantitative chemical analysis. Because the MVS was designed to obtain representative data on concentrations of contaminants in surface sediment throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, aliquots of the 160 MVS sediment samples were used in the analysis for the Organics Verification Study. However, unlike metals screening methods, organics screening methods are not specific to individual organic compounds, and are not available for some target organics. Therefore, only the quantitative analytical results were used in the organics verification evaluation. The results of the Organics Verification Study showed that sediment quality outside of Sinclair Inlet is unlikely to be impaired because of organic contaminants. Similar to the results for metals, in Sinclair Inlet, the distribution of residual organic contaminants is generally limited to nearshore areas already within the actively managed Puget Sound Naval Shipyard and Intermediate Maintenance Facility Superfund Site, where further source-control actions and monitoring are under way.

Kohn, Nancy P.; Brandenberger, Jill M.; Niewolny, Laurie A.; Johnston, Robert K.

2006-09-28

416

Active Flow Control on a Boundary-Layer-Ingesting Inlet  

NASA Technical Reports Server (NTRS)

Boundary layer ingestion (BLI) is explored as means to improve overall system performance for Blended Wing Body configuration. The benefits of BLI for vehicle system performance benefit are assessed with a process derived from first principles suitable for highly-integrated propulsion systems. This performance evaluation process provides framework within which to assess the benefits of an integrated BLI inlet and lays the groundwork for higher-fidelity systems studies. The results of the system study show that BLI provides a significant improvement in vehicle performance if the inlet distortion can be controlled, thus encouraging the pursuit of active flow control (AFC) as a BLI enabling technology. The effectiveness of active flow control in reducing engine inlet distortion was assessed using a 6% scale model of a 30% BLI offset, diffusing inlet. The experiment was conducted in the NASA Langley Basic Aerodynamics Research Tunnel with a model inlet designed specifically for this type of testing. High mass flow pulsing actuators provided the active flow control. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion was determined by 120 total pressure measurements located at the aerodynamic interface plane. The test matrix was limited to a maximum freestream Mach number of 0.15 with scaled mass flows through the inlet for that condition. The data show that the pulsed actuation can reduce distortion from 29% to 4.6% as measured by the circumferential distortion descriptor DC60 using less than 1% of inlet mass flow. Closed loop control of the actuation was also demonstrated using a sidewall surface static pressure as the response sensor.

Gorton, Susan Althoff; Owens, Lewis R.; Jenkins, Luther N.; Allan, Brian G.; Schuster, Ernest P.

2004-01-01

417

Control of Inflow Distortion in a Scarf Inlet  

NASA Technical Reports Server (NTRS)

The scarf inlet has the potential to reduce aircraft inlet noise radiation to the ground by reflecting it into the space above the engine. Without forward motion of the engine, the non-symmetry of the inlet causes inflow distortion which generates noise that is greater than the noise reduction of the scarf. However, acoustic evaluations of aircraft engines are often done on static test stands. A method to reduce inflow distortion by boundary layer suction is proposed and evaluated using a model of a high bypass ratio engine located in an anechoic chamber. The design goal of the flow control system is to make the inflow to the inlet circumferentially uniform and to eliminate reversed flow. This minimizes the inflow distortion and allows for acoustic evaluation of the scarf inlet on a static test stand. The inlet boundary layer suction effectiveness is evaluated both by aerodynamic and by acoustic measurements. Although the design goal is not met, the control system is found to have a beneficial effect on the engine operation, reducing blade stall and speed variation. This is quantified by two acoustic benefits, reduction both of the variability of tone noise and of the low frequency wideband noise due to the inflow distortion. It is felt that a compromise in the manufacture of the control hardware contributes to the inability of the control system to perform as expected from the analysis. The control system with sufficient authority is felt to have the potential to permit reliable acoustic testing in a static configuration of engines with non-symmetric inlets. Because the control system can improve operation of the engine, it may also have the potential to reduce noise and vibration and enhance engine longevity during low speed ground operations in the terminal area.

Gerhold, Carl H.; Clark, Lorenzo R.; Biedron, Robert T.

2002-01-01

418

Corrugated and Composite Nozzle-Inlets for Thrust and Noise Benefits  

NASA Technical Reports Server (NTRS)

The following research results are based on development of an approach previously proposed and investigated in for optimum nozzle design to obtain maximum thrust. The design was denoted a Telescope nozzle. A Telescope nozzle contains one or several internal designs, which are inserted at certain locations into a divergent conical or planar main nozzle near its exit. Such a design provides additional thrust augmentation over 20% by comparison with the optimum single nozzle of equivalent lateral area, What is more, experimental acoustic tests have discovered an essential noise reduction due to application of Telescope nozzles. In this paper, some additional theoretical results are presented for Telescope nozzles and a similar approach is applied for aero-performance improvement of a supersonic inlet. Numerical simulations were conducted for supersonic flow into the divergent portion of a 2D or axisymmetric nozzle with several plane or conical designs as well as into a 2D or axisymmetric supersonic inlet with a forebody. The Kryko-Godunov marching numerical scheme for inviscid supersonic flows was used. Several cases were tested using the NASA CFL3d and IM/MSU Russian codes based on the full Navier-Stokes equations. Numerical simulations were conducted for non reacting flows (both codes) as well as for real high temperature gas flows with non-equilibrium chemical reactions (the latter code). In general, these simulations have confirmed essential benefits of Telescope design applications in propulsion system. Some preliminary numerical simulations of several typical inlet designs were conducted with the goal of inlet design optimization for maneuvering flight conditions.

Gilinsky, M.; Blankson, I. M.; Gromov, V. G.; Sakharov, V. I.

2004-01-01

419

Temperature  

NSDL National Science Digital Library

This topic in depth begins with the About Temperature (1) Web site, written by Beverly T. Lynds of Unidata, which is a program that works to enable university researchers and educators to acquire and use atmospheric and related data. The one-page site explains what temperature is, the development of thermometers, heat and thermodynamics, and other related topics. The second site is maintained by the University of Execter's Centre for Innovation in Mathematics Teaching. Actually an online tool called Conversion Calculator for Units of Temperature (2), the site allows users to type in any value, choose a significant figure, press "convert it," and get that value in Kelvin, Celsius, Fahrenheit, r'aumur, and rankine units. The next site is a lesson plan from AskEric.com entitled Temperature: Is it Hot or Cold? (3). Written for 2nd graders, the lesson demonstrates to how to read thermometers, determine their rise or fall, record temperatures, and take temperatures of various items. The fourth site, Surface Temperature Analysis (4), is presented by NASA's Goddard Institute for Space Studies. Here, visitors can view graphs, maps, animations, and station data of global surface temperatures. For example, the animation covers 12-month means from 1971 to 1999. The History Behind the Thermometer (5) Web site, from About.com, explores what a thermometer is, how it works, and how it came into being. The sixth site, entitled Science Shack (6) and offered by the BBC, answers the question, Why do we have two different temperature scales, Celsius and Fahrenheit? The site explains how to create your own thermometer like Galileo's, tells how it works, and why we use other types today. The next site is provided by National Oceanic and Atmospheric Administration (NOAA) and presents US State temperature extremes and drought information (7). Visitors can see all-time temperature maximums and minimums by state, monthly temperatures by state, and more. The last site is an all-inclusive temperature site called Temperature World (8). Everything from news, science, organizations, general interest, games, and more -- all related to temperature -- can be found here.

Brieske, Joel A.

2002-01-01

420

Effects of LWR coolant environments on fatigue design curves of carbon and low-alloy steels  

SciTech Connect

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the code specify fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data indicate that the Code fatigue curves may not always be adequate in coolant environments. This report summarizes work performed by Argonne National Laboratory on fatigue of carbon and low-alloy steels in light water reactor (LWR) environments. The existing fatigue S-N data have been evaluated to establish the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, temperature, orientation, and sulfur content on the fatigue life of these steels. Statistical models have been developed for estimating the fatigue S-N curves as a function of material, loading, and environmental variables. The results have been used to estimate the probability of fatigue cracking of reactor components. The different methods for incorporating the effects of LWR coolant environments on the ASME Code fatigue design curves are presented.

Chopra, O.K.; Shack, W.J. [Argonne National Lab., IL (United States)

1998-03-01

421

Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket  

DOEpatents

The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Christiansen, D.W.; Schively, D.P.

1982-01-19

422

Top-mounted inlet system feasibility for transonic-supersonic fighter aircraft. [V/STOL aircraft  

NASA Technical Reports Server (NTRS)

The more salient findings are presented of recent top inlet performance evaluations aimed at assessing the feasibility of top-mounted inlet systems for transonic-supersonic fighter aircraft applications. Top inlet flow field and engine-inlet performance test data show the influence of key aircraft configuration variables-inlet longitudinal position, wing leading-edge extension planform area, canopy-dorsal integration, and variable incidence canards-on top inlet performance over the Mach range of 0.6 to 2.0. Top inlet performance data are compared with those or more conventional inlet/airframe integrations in an effort to assess the viability of top-mounted inlet systems relative to conventional inlet installations.

Williams, T. L.; Hunt, B. L.; Smeltzer, D. B.; Nelms, W. P.

1981-01-01

423

Surface Water Quality Survey of Northern Indian River Lagoon from Sebastian Inlet to Mosquito Lagoon  

NASA Astrophysics Data System (ADS)

Following news of an emerging brown tide algal bloom in the northern Indian River Lagoon (IRL), researchers sought to gain insight into the surface water quality in the IRL, as well as the extent of the algae coverage. A Portable SeaKeeper from YSI, mounted to a personal watercraft-based coastal profiling system, autonomously collected and analyzed the surface water. The system operates by recording sample data every 12 seconds while continuously underway at speeds up to and greater than 50 km/hr. The researchers covered a transect that started at Sebastian Inlet and followed a zig-zag path extending up through the Haulover Canal and into the Mosquito Lagoon. The survey path covered 166.7 km, and collected 2248 samples. Along the way stops were made at water quality stations used by the Saint John's River Water Management District, so that the data collected can be incorporated into ongoing monitoring efforts. The system analyzed the surface water for dissolved oxygen, pH, chlorophyll-a, salinity, temperature, turbidity, refined fuels, and CDOM. In the two days following the lagoon survey, the inlets at Port Canaveral and Sebastian were also surveyed for tidal currents and hydrography. The IRL transect survey data recorded evidence of the southern extent of the algae bloom in both chlorophyll-a and pH levels. Visual evidence of the bloom was striking as the water in the northern IRL turned a milk chocolaty brown color. Chlorophyll-a levels in the two inlets suggested bloom activity at these locations; however this bloom was different. This oceanic bloom was a result of a persistent upwelling event along the East Florida shelf, and the color was a paler green-yellow. The near-synoptic nature of the comprehensive lagoon survey, conducted in just over 7 hours, allows researchers to obtain a better understanding of water quality in coastal lagoons. Elevated levels of salinity, temperature, and refined fuels in the northern IRL indicate a low exchange rate and absence of flushing. Coordinated studies of circulation through the Haulover Canal, Ponce Inlet and Sebastian Inlet would aid in understanding the genesis of future bloom events.;

Weaver, R. J.; Webb, B. M.

2012-12-01

424

Numerical Simulation of Non-Rotating and Rotating Coolant Channel Flow Fields. Part 1  

NASA Technical Reports Server (NTRS)

Future generations of ultra high bypass-ratio jet engines will require far higher pressure ratios and operating temperatures than those of current engines. For the foreseeable future, engine materials will not be able to withstand the high temperatures without some form of cooling. In particular the turbine blades, which are under high thermal as well as mechanical loads, must be cooled. Cooling of turbine blades is achieved by bleeding air from the compressor stage of the engine through complicated internal passages in the turbine blades (internal cooling, including jet-impingement cooling) and by bleeding small amounts of air into the boundary layer of the external flow through small discrete holes on the surface of the blade (film cooling and transpiration cooling). The cooling must be done using a minimum amount of air or any increases in efficiency gained through higher operating temperature will be lost due to added load on the compressor stage. Turbine cooling schemes have traditionally been based on extensive empirical data bases, quasi-one-dimensional computational fluid dynamics (CFD) analysis, and trial and error. With improved capabilities of CFD, these traditional methods can be augmented by full three-dimensional simulations of the coolant flow to predict in detail the heat transfer and metal temperatures. Several aspects of turbine coolant flows make such application of CFD difficult, thus a highly effective CFD methodology must be used. First, high resolution of the flow field is required to attain the needed accuracy for heat transfer predictions, making highly efficient flow solvers essential for such computations. Second, the geometries of the flow passages are complicated but must be modeled accurately in order to capture all important details of the flow. This makes grid generation and grid quality important issues. Finally, since coolant flows are turbulent and separated the effects of turbulence must be modeled with a low Reynolds number turbulence model to accurately predict details of heat transfer.

Rigby, David L.

2000-01-01

425

Influence of coolant pH on corrosion of 6061 aluminum under reactor heat transfer conditions  

SciTech Connect

To support the design of the Advanced Neutron Source (ANS), an experimental program was conducted wherein aluminum alloy specimens were exposed at high heat fluxes to high-velocity aqueous coolants in a corrosion test loop. The aluminum alloys selected for exposure were candidate fuel cladding materials, and the loop system was constructed to emulate the primary coolant system for the proposed ANS reactor. One major result of this program has been the generation of an experimental database defining oxide film growth on 6061 aluminum alloy cladding. Additionally, a data correlation was developed from the database to permit the prediction of film growth for any reasonable thermal-hydraulic excursion. This capability was utilized effectively during the conceptual design stages of the reactor. During the course of this research, it became clear that the kinetics of film growth on the aluminum alloy specimens were sensitively dependent on the chemistry of the aqueous coolant and that relatively small deviations from the intended pH 5 operational level resulted in unexpectedly large changes in the corrosion behavior. Examination of the kinetic influences and the details of the film morphology suggested that a mechanism involving mass transport from other parts of the test loop was involved. Such a mechanism would also be expected to be active in the operating reactor. This report emphasizes the results of experiments that best illustrate the influence of the nonthermal-hydraulic parameters on film growth and presents data to show that comparatively small variations in pH near 5.0 invoke a sensitive response. Simply, for operation in the temperature and heat flux range appropriate for the ANS studies, coolant pH levels from 4.5 to 4.9 produced significantly less film growth than those from pH 5.1 to 6. A mechanism for this behavior based on the concept of treating the entire loop as an active corrosion system is presented.

Pawel, S.J.; Felde, D.K.; Pawel, R.E.

1995-10-01

426

Development and Transient Analysis of a Helical-coil Steam Generator for High Temperature Reactors  

SciTech Connect

A high temperature gas-cooled reactor (HTGR) is under development by the Next Generation Nuclear Plant (NGNP) Project at the Idaho National Laboratory (INL). Its design emphasizes electrical power production which may potentially be coupled with process heat for hydrogen production and other industrial applications. NGNP is considering a helical-coil steam generator for the primary heat transport loop heat exchanger based on its increased heat transfer and compactness when compared to other steam generators. The safety and reliability of the helical-coil steam generator is currently under evaluation as part of the development of NGNP. Transients, such as loss of coolant accidents (LOCA), are of interest in evaluating the safety of steam generators. In this study, a complete steam generator inlet pipe break (double ended pipe break) LOCA was simulated by an exponential loss of primary side pressure. For this analysis, a model of the helical-coil steam generator was developed using RELAP5-3D, an INL inhouse systems analysis code. The steam generator model behaved normally during the transient simulating the complete steam generator inlet pipe break LOCA. Further analysis is required to comprehensively evaluate the safety and reliability of the helical-coil steam generator design in the NGNP setting.

Nathan V. Hoffer; Nolan A. Anderson; Piyush Sabharwall

2011-08-01

427

Detailed investigation of flowfields within large scale hypersonic inlet models  

NASA Technical Reports Server (NTRS)

Analytical and experimental investigations were conducted to determine the characteristics of the internal flows in model passages representative of hypersonic inlets and also sufficiently large for meaningful data to be obtained. Three large-scale inlet models, each having a different compression ratio, were designed to provide high performance and approximately uniform static-pressure distributions at the throat stations. A wedge forebody was used to simulate the flowfield conditions at the entrance of the internal passages, thus removing the actual vehicle forebody from consideration in the design of the wind-tunnel models. Tests were conducted in a 3.5 foot hypersonic wind tunnel at a nominal test Mach number of 7.4 and freestream unit Reynolds number of 2,700,000 per foot. From flowfield survey data the inlet entrance, the entering inviscid and viscous flow conditions were determined prior to the analysis of the data obtained in the internal passages. Detailed flowfield survey data were obtained near the centerlines of the internal passages to define the boundary-layer development on the internal surfaces and the internal shock-wave configuration. Finally, flowfield data were measured across the throats of the inlet models to evaluate the internal performance of the internal passages. These data and additional results from surface instrumentation and flow visualization studies were utilized to determine the internal flowfield patterns and the inlet performance.

Seebaugh, W. R.; Doran, R. W.; Decarlo, J. P.

1971-01-01

428

Rapid Calculations of Three-Dimensional Inlet/Fan Interaction  

NASA Technical Reports Server (NTRS)

Two computational fluid dynamics codes have been merged to permit rapid calculations of inlet/fan interaction. Inlets are modeled using the WIND-US Navier-Stokes code. Fans are modeled using a new three-dimensional Euler code called CSTALL that solves the flow through the entire compression system but models blade rows using body forces for turning and loss. The body force model is described and it is shown how unknown terms in the model can be estimated from other Navier-Stokes solutions of the blade rows run separately. The inlet and fan calculations are run simultaneously and are coupled at an interface plane using a third code called SYNCEX that is described briefly. Results are shown for an axisymmetric nacelle at high angle of attack modeled both as an isolated inlet and coupled to a single stage fan. The isolated inlet calculations are unrealistic after the flow separates but the coupled codes can model large regions of separated flow extending from the lower lip of the nacelle into the fan rotor.

Chima, Rodrick V.

2007-01-01

429

Inlet distortion effects in aircraft propulsion system integration  

NASA Technical Reports Server (NTRS)

A tutorial survey of inlet flow distortion effects on engine performance and stability is presented. Inlet distortions in aero engines arise through a variety of causes. They can be essentially steady, due to non-axisymmetric intake duct geometry, or time varying, for example from flow separation off the lip of the inlet during maneuvers or shock-induced separation during supersonic flight. Whatever the cause, the result is generally a decrease in performance and, more importantly, a lessening of the stable flow range of the compressor. The distortions are generally three-dimensional. It is an extremely useful simplification to break them, at least conceptually, into radial and circumferential non-uniformities and approach each separately. Purely radial distortions can be treated by the methods that were developed for designing compressors in nominally axisymmetric inlet flow, and this type of distortion will be only briefly discussed. Circumferential non-uniformities, however, introduce additional fluid dynamic features into the analysis of compressor behavior and often have the larger impact on performance and stability. Thus we concentrate mainly on the effects of steady circumferential inlet flow distortion.

Longley, J. P.; Greitzer, E. M.

1992-01-01

430

Design and Analysis Tool for External-Compression Supersonic Inlets  

NASA Technical Reports Server (NTRS)

A computational tool named SUPIN has been developed to design and analyze external-compression supersonic inlets for aircraft at cruise speeds from Mach 1.6 to 2.0. The inlet types available include the axisymmetric outward-turning, two-dimensional single-duct, two-dimensional bifurcated-duct, and streamline-traced Busemann inlets. The aerodynamic performance is characterized by the flow rates, total pressure recovery, and drag. The inlet flowfield is divided into parts to provide a framework for the geometry and aerodynamic modeling and the parts are defined in terms of geometric factors. The low-fidelity aerodynamic analysis and design methods are based on analytic, empirical, and numerical methods which provide for quick analysis. SUPIN provides inlet geometry in the form of coordinates and surface grids useable by grid generation methods for higher-fidelity computational fluid dynamics (CFD) analysis. SUPIN is demonstrated through a series of design studies and CFD analyses were performed to verify some of the analysis results.

Slater, John W.

2012-01-01

431

Numerical analysis of flow through scramjet engine inlets  

NASA Technical Reports Server (NTRS)

A set of computer programs was developed to analyze flow through supersonic combustion ramjet (scramjet) inlets. These programs solve either the two or three dimensional Euler/Navier-Stokes equations in full conservation form by MacCormack's explicit or explicit-implicit method. An algebraic two-layer eddy viscosity model is used for turbulent flow calculations. The programs are operational in Control Data CYBER-200 series vector-processing computer system and were optimized to take maximum advantage of the vector processing capability of the system. Since their development, the programs were extensively verified and used to analyze a number of very complex inlet configurations. Results are presented from two-dimensional, quasi-three-dimensional, and three-dimensional analyses of the inlet flow field to illustrate the use of the program.

Kumar, Ajay

1987-01-01

432

Numerical analysis of flow through scramjet engine inlets  

NASA Technical Reports Server (NTRS)

A set of computer programs has been developed to analyze flow through supersonic combustion ramjet (scramjet) inlets. These programs solve either the two- or three-dimensional Euler/Navier-Stokes equations in full conservation form by MacCormack's explicit or explicit-implicit method. An algebraic two-layer eddy viscosity model is used for turbulent flow calculations. The programs are operational on Control Data CYBER-200 series vector-processing computer system and have been optimized to take maximum advantage of the vector processing capability of the system. Since their development, the programs have been extensively verified and used to analyze a number of very complex inlet configurations. In this paper, results are presented from two-dimensional, quasi-three-dimensional, and three-dimensional analyses of the inlet flow field to illustrate the use of the programs.

Kumar, Ajay

1987-01-01

433

Numerical and Test Investigation on an Aircraft Inlet Distortion  

NASA Astrophysics Data System (ADS)

Subscale wind tunnel test of an aircraft vehicle is performed at different Mach number, mass-flow and angle of attack. CFD model, corrected by test results, is also presented to predict inlet performance and total pressure distortion. The result shows total pressure recovery decreases and distortion level rises when Mach number increases from subsonic to supersonic speed, AOA is negative and mass-flow value is too large or too small. Compared linear interpolation based on test result of discrete probes, numerical simulation has advantages in showing inlet flow field predicting actual surface distortion level in AIP plane. Swirl distortion is induced by vortex near the fuselage and adjustable ramp and can strengthen total pressure distortion in AIP at negative AOA. And appropriate suction mass-flow coefficient (1.7% to 3%) is beneficial for inlet performance and total pressure distortion control.

Zhang, Zhang; Hou, Anping; Chen, Yinxiu; Tuo, Wei; Xia, Aiguo

2013-09-01

434

Nuclear criticality safety assessment of the proposed CFC replacement coolants  

SciTech Connect

The neutron multiplication characteristics of refrigerant-114 (R-114) and proposed replacement coolants perfluorobutane (C{sub 4}F{sub 10}) and cycloperfluorobutane C{sub 4}F{sub 8}) have been compared by evaluating the infinite media multiplication factors of UF{sub 6}/H/coolant systems and by replacement calculations considering a 10-MW freezer/sublimer. The results of these comparisons demonstrate that R-114 is a neutron absorber, due to its chlorine content, and that the alternative fluorocarbon coolants are neutron moderators. Estimates of critical spherical geometries considering mixtures of UF{sub 6}/HF/C{sub 4}F{sub 10} indicate that the flourocarbon-moderated systems are large compared with water-moderated systems. The freezer/sublimer calculations indicate that the alternative coolants are more reactive than R-114, but that the reactivity remains significantly below the condition of water in the tubes, which was a limiting condition. Based on these results, the alternative coolants appear to be acceptable; however, several follow-up tasks have been recommended, and additional evaluation will be required on an individual equipment basis.

Jordan, W.C.; Dyer, H.R.

1993-12-01

435

Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate  

NASA Technical Reports Server (NTRS)

Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

Kamman, J. H.; Hall, C. L.

1975-01-01

436

Computer programs for calculating potential flow in propulsion system inlets  

NASA Technical Reports Server (NTRS)

In the course of designing inlets, particularly for VTOL and STOL propulsion systems, a calculational procedure utilizing three computer programs evolved. The chief program is the Douglas axisymmetric potential flow program called EOD which calculates the incompressible potential flow about arbitrary axisymmetric bodies. The other two programs, original with Lewis, are called SCIRCL AND COMBYN. Program SCIRCL generates input for EOD from various specified analytic shapes for the inlet components. Program COMBYN takes basic solutions output by EOD and combines them into solutions of interest, and applies a compressibility correction.

Stockman, N. O.; Button, S. L.

1973-01-01

437

Isolated rotor noise due to inlet distortion or turbulence  

NASA Technical Reports Server (NTRS)

Theoretical formulation, analysis, and results are presented that are necessary to analyze quadrupole noise generated from a loaded, subsonic rotor because of its interaction with an inflow distortion or inlet turbulence. The ratio of quadrupole to dipole noise is largely a function of the axial Mach number, wheel tip Mach number, rotor solidity, and total pressure ratio across the rotor. It is relatively independent of the specific form of the inflow distortion or inlet turbulence. Comparisons with experimental data only succeed in predicting gross levels at a given speed and fail to predict the variation of noise at fixed speed with flow and pressure ratio. Likely sources of this discrepancy are discussed.

Mani, R.

1974-01-01

438

On-line distortion analysis system inlet-engine test  

SciTech Connect

A system for near-real-time distortion analysis support of aircraft turbine engine-inlet altitude testing is described. Target applications include both subscale and full-scale inlet-engine compatibility testing in wind tunnel, direct-connect, and free-jet configurations. The system digitizes analog-format, time-dependent data and combines it with digital-format, steady-state data. A high-speed data bus and multiple array processors provide for on-line execution of complex distortion analysis algorithms to compute and display distortion indices, histograms, isobar plots, and surge margin consumption. Analysis algorithms are programmed using a high-level language (FORTRAN 77).

Morton, W.K.; Lazalier, G.R.; Rose, C.D.; Lauer, R.F.

1991-06-01

439

Large perturbation flow field analysis and simulation for supersonic inlets  

NASA Technical Reports Server (NTRS)

An analysis technique for simulation of supersonic mixed compression inlets with large flow field perturbations is presented. The approach is based upon a quasi-one-dimensional inviscid unsteady formulation which includes engineering models of unstart/restart, bleed, bypass, and geometry effects. Numerical solution of the governing time dependent equations of motion is accomplished through a shock capturing finite difference algorithm, of which five separate approaches are evaluated. Comparison with experimental supersonic wind tunnel data is presented to verify the present approach for a wide range of transient inlet flow conditions.

Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.

1984-01-01

440

Development of a three-dimensional supersonic inlet flow analysis  

NASA Technical Reports Server (NTRS)

A method for computing three dimensional flow in supersonic inlets is described. An approximate set of governing equations is given for viscous flows which have a primary flow direction. The governing equations are written in general orthogonal coordinates. These equations are modified in the subsonic region of the flow to prevent the phenomenon of branching. Results are presented for the two sample cases: a Mach number equals 2.5 flow in a square duct, and a Mach number equals 3.0 flow in a research jet engine inlet. In the latter case the computed results are compared with the experimental data. A users' manual is included.

Buggeln, R. C.; Mcdonald, H.; Levy, R.; Kreskovsky, J. P.

1980-01-01

441

33 CFR 159.119 - Operability test; temperature range.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Operability test; temperature range. 159.119 Section 159...Testing § 159.119 Operability test; temperature range. The device must operate in an ambient temperature of 5 °C with inlet operating...

2010-07-01

442

33 CFR 159.119 - Operability test; temperature range.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Operability test; temperature range. 159.119 Section 159...Testing § 159.119 Operability test; temperature range. The device must operate in an ambient temperature of 5 °C with inlet operating...

2013-07-01

443

33 CFR 159.119 - Operability test; temperature range.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Operability test; temperature range. 159.119 Section 159...Testing § 159.119 Operability test; temperature range. The device must operate in an ambient temperature of 5 °C with inlet operating...

2011-07-01

444

33 CFR 159.119 - Operability test; temperature range.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Operability test; temperature range. 159.119 Section 159...Testing § 159.119 Operability test; temperature range. The device must operate in an ambient temperature of 5 °C with inlet operating...

2014-07-01

445

33 CFR 159.119 - Operability test; temperature range.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Operability test; temperature range. 159.119 Section 159...Testing § 159.119 Operability test; temperature range. The device must operate in an ambient temperature of 5 °C with inlet operating...

2012-07-01

446

Numerical investigation of the aerodynamic performance affected by spiral inlet and outlet in a positive displacement blower  

NASA Astrophysics Data System (ADS)

The flow in the positive displacement blower is very complex. The existing two-dimensional numerical simulation cannot provide the detailed flow information, especially flow characteristics along the axial direction, which is unfavorable to improve the performance of positive displacement blower. To investigate the effects of spiral inlet and outlet on the aerodynamic performance of positive displacement blower, three-dimensional unsteady flow characteristics in a three-lobe positive displacement blower with and without the spiral inlet and outlet are simulated by solving Navier-Stokes equations coupled with RNG k-? turbulent model. In the numerical simulation, the dynamic mesh technique and overset mesh updating method are used. The computational results are compared with the experimental measurements on the variation of flow rate with the outlet pressure to verify the validity of the numerical method presented. The results show that the mass flow rate with the change of pressure is slightly affected by the application of spiral inlet and outlet, but the internal flow state is largely affected. In the exhaust region, the fluctuations of pressure, velocity and temperature as well as the average values of velocity are significantly reduced. This illustrates that the spiral outlet can effectively suppress the fluctuations of pressure, thus reducing reflux shock and energy dissipation. In the intake area, the average value of pressure, velocity and temperature are slightly declined, but the fluctuations of them are significantly reduced, indicating that the spiral inlet plays the role in making the flow more stable. The numerical results obtained reveal the three-dimensional flow characteristics of the positive displacement blower with spiral inlet and outlet, and provide useful reference to improve performance and empirical correction in the noise-reduction design of the positive displacement blowers.

Liu, Xiaomin; Lu, Jun; Gao, Renheng; Xi, Guang

2013-09-01

447

A comparison of predicted and measured inlet distortion flows in a subsonic axial inlet flow compressor rotor  

NASA Technical Reports Server (NTRS)

Detailed flow measurements were taken inside an isolated axial compressor rotor operating subsonically near peak efficiency. These Laser Anemometer measurements were made with two inlet velocity profiles. One profile consisted of an unmodified baseline flow, and the second profile was distorted by placing axisymmetric screens on the hub and shroud well upstream of the rotor. A detailed comparison in the rotor relative reference frame between a Navier-Stokes solver and the measured experimental results showed good agreement between the predicted and measured flows. A primary flow is defined in the rotor and deviations and the computed predictions is made to assess the development of a passage vortex due to the distortion of the inlet flow. Computer predictions indicate that a distorted inlet profile has a minimal effect on the development of the flow in the rotor passage and the resulting passage vortex.

Owen, Albert K.

1992-01-01

448

Fracture mechanics evaluation for at typical PWR primary coolant pipe  

SciTech Connect

For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

Tanaka, T. [Kansai Electric Power Company, Osaka (Japan); Shimizu, S.; Ogata, Y. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan)

1997-04-01

449

Temperature  

NASA Technical Reports Server (NTRS)

The problems in human comfort in heat stress are emphasized, with less emphasis placed upon cold exposure problems. Physiological parameters related to human thermal interactions are discussed, as well as data concerning thermal protective clothing. The energy balance equation, heat transfer equation, thermal comfort, heat stress, and cold stress are also considered. A two node model of human temperature regulation in FORTRAN is appended.

Berenson, P. J.; Robertson, W. G.

1973-01-01

450

An analysis of heat transfer after loss of primary coolant in the SP-100 reactor system  

NASA Astrophysics Data System (ADS)

This study determines design guidelines for the SP-100 space reactor core cooling system after a loss of coolant accident. The Thermal Systems Analysis Code (TSAP) calculated the temperatures within the fuel assemblies as a result of the fuel decay heat. TSAP is a lumped-parameter network analysis code capable of performing radiative and conductive heat transfer analysis. The reactor core was assumed to void of coolant instantaneously following a LOCA. The reactor core model consisted of individual fuel pin assemblies containing 36 fuel pins surrounding a central cooling channel. This central cooling channel, or bayonet, is a secondary cooling loop within the reactor core. The bayonet cooling is a safety feature designed to keep the core from reaching temperatures at which the uranium dissociates from the uranium-nitride fuel. TSAP calculated the fuel pin temperatures due to decay heat transient. The performance of the bayonets within a generic reactor core was compared to an actual design. Design guidance was established based on the performance of the bayonets in the generic core.

Robbins, Donald W.

1988-03-01

451

Aerodynamic characteristics of a series of twin-inlet air-breathing missile configurations. 3: Axisymmetric and two-dimensional inlets at subsonic-transonic speeds  

NASA Technical Reports Server (NTRS)

A series of air-breathing missile configurations was investigated to provide a data base for the design of such missiles. The model could be configurated with either twin axisymmetric or two dimensional inlets. Three circumferential inlet locations were investigated: 90 deg, 115 deg, and 135 deg from the top center. Two vertical wing locations, as well as wingless configurations, were used. Three tail configurations were formed by locating the tail surfaces either on the inlet fairing or on the inlet fairing or on fairings on the body. The surfaces were used to provide pitch control. Two dimensional inlets with extended compression surfaces, used to improve the angle-of-attack performance of the inlets for wingless configurations, were also investigated. The twin axisymmetric two dimensional inlet types without internal flow are covered, and the boost configuration of an air-breathing missile is simulated.

Hayes, C.

1983-01-01