Improvements to Filter Debris Analysis in Aviation Propulsion Systems

DTIC Science & Technology

2012-12-01

been applied to the external scavenge filter fitted to the T56 -A-14 and T-56-A-15 engines (powering the P3C and C130-H aircraft respectively...15 3. AUTOMATED ANALYSIS OF T56 ENGINE OIL FILTER DEBRIS...................... 15 3.1 Historical Practices...for T56 .................................................................................... 15 3.2 FilterCHECK 290

78 FR 16604 - Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... unsafe condition as the engine air inlet filter is subject to icing. We are issuing this AD to require... warmer air conditions. The subsequent investigation identified that the engine air inlet filter is... with a manually controlled alternate air valve which bypasses the inlet air filter and provides...

Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Connolly, Joseph W.

2016-01-01

This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Connolly, Joseph W.

2015-01-01

This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40,000) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

Optimized tuner selection for engine performance estimation

NASA Technical Reports Server (NTRS)

Simon, Donald L. (Inventor); Garg, Sanjay (Inventor)

2013-01-01

A methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine which seeks to minimize the theoretical mean-squared estimation error. Theoretical Kalman filter estimation error bias and variance values are derived at steady-state operating conditions, and the tuner selection routine is applied to minimize these values. The new methodology yields an improvement in on-line engine performance estimation accuracy.

Subsonic flight test evaluation of a propulsion system parameter estimation process for the F100 engine

NASA Technical Reports Server (NTRS)

Orme, John S.; Gilyard, Glenn B.

1992-01-01

Integrated engine-airframe optimal control technology may significantly improve aircraft performance. This technology requires a reliable and accurate parameter estimator to predict unmeasured variables. To develop this technology base, NASA Dryden Flight Research Facility (Edwards, CA), McDonnell Aircraft Company (St. Louis, MO), and Pratt & Whitney (West Palm Beach, FL) have developed and flight-tested an adaptive performance seeking control system which optimizes the quasi-steady-state performance of the F-15 propulsion system. This paper presents flight and ground test evaluations of the propulsion system parameter estimation process used by the performance seeking control system. The estimator consists of a compact propulsion system model and an extended Kalman filter. The extended Laman filter estimates five engine component deviation parameters from measured inputs. The compact model uses measurements and Kalman-filter estimates as inputs to predict unmeasured propulsion parameters such as net propulsive force and fan stall margin. The ability to track trends and estimate absolute values of propulsion system parameters was demonstrated. For example, thrust stand results show a good correlation, especially in trends, between the performance seeking control estimated and measured thrust.

Aircraft Turbofan Engine Health Estimation Using Constrained Kalman Filtering

NASA Technical Reports Server (NTRS)

Simon, Dan; Simon, Donald L.

2003-01-01

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter is a combination of a standard Kalman filter and a quadratic programming problem. The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is proven theoretically and shown via simulation results obtained from application to a turbofan engine model. This model contains 16 state variables, 12 measurements, and 8 component health parameters. It is shown that the new algorithms provide improved performance in this example over unconstrained Kalman filtering.

Band-pass filtering algorithms for adaptive control of compressor pre-stall modes in aircraft gas-turbine engine

NASA Astrophysics Data System (ADS)

Kuznetsova, T. A.

2018-05-01

The methods for increasing gas-turbine aircraft engines' (GTE) adaptive properties to interference based on empowerment of automatic control systems (ACS) are analyzed. The flow pulsation in suction and a discharge line of the compressor, which may cause the stall, are considered as the interference. The algorithmic solution to the problem of GTE pre-stall modes’ control adapted to stability boundary is proposed. The aim of the study is to develop the band-pass filtering algorithms to provide the detection functions of the compressor pre-stall modes for ACS GTE. The characteristic feature of pre-stall effect is the increase of pressure pulsation amplitude over the impeller at the multiples of the rotor’ frequencies. The used method is based on a band-pass filter combining low-pass and high-pass digital filters. The impulse response of the high-pass filter is determined through a known low-pass filter impulse response by spectral inversion. The resulting transfer function of the second order band-pass filter (BPF) corresponds to a stable system. The two circuit implementations of BPF are synthesized. Designed band-pass filtering algorithms were tested in MATLAB environment. Comparative analysis of amplitude-frequency response of proposed implementation allows choosing the BPF scheme providing the best quality of filtration. The BPF reaction to the periodic sinusoidal signal, simulating the experimentally obtained pressure pulsation function in the pre-stall mode, was considered. The results of model experiment demonstrated the effectiveness of applying band-pass filtering algorithms as part of ACS to identify the pre-stall mode of the compressor for detection of pressure fluctuations’ peaks, characterizing the compressor’s approach to the stability boundary.

Emergency Control Aircraft System Using Thrust Modulation

NASA Technical Reports Server (NTRS)

Burken, John J. (Inventor); Burcham, Frank W., Jr. (Inventor)

2000-01-01

A digital longitudinal Aircraft Propulsion Control (APC system of a multiengine aircraft is provided by engine thrust modulation in response to comparing an input flightpath angle signal (gamma)c from a pilot thumbwheel. or an ILS system with a sensed flightpath angle y to produce an error signal (gamma)e that is then integrated (with reasonable limits) to generate a drift correction signal to be added to the error signal (gamma)e after first subtracting a lowpass filtered velocity signal Vel(sub f) for phugoid damping. The output error signal is multiplied by a constant to produce an aircraft thrust control signal ATC of suitable amplitude to drive a throttle servo for all engines. each of which includes its own full-authority digital engine control (FADEC) computer. An alternative APC system omits sensed flightpath angle feedback and instead controls the flightpath angle by feedback of the lowpass filtered velocity signal Vel(sub f) which also inherently provides phugoid damping. The feature of drift compensation is retained.

14 CFR 33.71 - Lubrication system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... in which an aircraft is expected to operate. (b) Oil strainer or filter. There must be an oil strainer or filter through which all of the engine oil flows. In addition: (1) Each strainer or filter... normal rate through the rest of the system with the strainer or filter element completely blocked. (2...

Enhanced Bank of Kalman Filters Developed and Demonstrated for In-Flight Aircraft Engine Sensor Fault Diagnostics

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2005-01-01

In-flight sensor fault detection and isolation (FDI) is critical to maintaining reliable engine operation during flight. The aircraft engine control system, which computes control commands on the basis of sensor measurements, operates the propulsion systems at the demanded conditions. Any undetected sensor faults, therefore, may cause the control system to drive the engine into an undesirable operating condition. It is critical to detect and isolate failed sensors as soon as possible so that such scenarios can be avoided. A challenging issue in developing reliable sensor FDI systems is to make them robust to changes in engine operating characteristics due to degradation with usage and other faults that can occur during flight. A sensor FDI system that cannot appropriately account for such scenarios may result in false alarms, missed detections, or misclassifications when such faults do occur. To address this issue, an enhanced bank of Kalman filters was developed, and its performance and robustness were demonstrated in a simulation environment. The bank of filters is composed of m + 1 Kalman filters, where m is the number of sensors being used by the control system and, thus, in need of monitoring. Each Kalman filter is designed on the basis of a unique fault hypothesis so that it will be able to maintain its performance if a particular fault scenario, hypothesized by that particular filter, takes place.

Real-Time Diagnosis of Faults Using a Bank of Kalman Filters

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2006-01-01

A new robust method of automated real-time diagnosis of faults in an aircraft engine or a similar complex system involves the use of a bank of Kalman filters. In order to be highly reliable, a diagnostic system must be designed to account for the numerous failure conditions that an aircraft engine may encounter in operation. The method achieves this objective though the utilization of multiple Kalman filters, each of which is uniquely designed based on a specific failure hypothesis. A fault-detection-and-isolation (FDI) system, developed based on this method, is able to isolate faults in sensors and actuators while detecting component faults (abrupt degradation in engine component performance). By affording a capability for real-time identification of minor faults before they grow into major ones, the method promises to enhance safety and reduce operating costs. The robustness of this method is further enhanced by incorporating information regarding the aging condition of an engine. In general, real-time fault diagnostic methods use the nominal performance of a "healthy" new engine as a reference condition in the diagnostic process. Such an approach does not account for gradual changes in performance associated with aging of an otherwise healthy engine. By incorporating information on gradual, aging-related changes, the new method makes it possible to retain at least some of the sensitivity and accuracy needed to detect incipient faults while preventing false alarms that could result from erroneous interpretation of symptoms of aging as symptoms of failures. The figure schematically depicts an FDI system according to the new method. The FDI system is integrated with an engine, from which it accepts two sets of input signals: sensor readings and actuator commands. Two main parts of the FDI system are a bank of Kalman filters and a subsystem that implements FDI decision rules. Each Kalman filter is designed to detect a specific sensor or actuator fault. When a sensor or actuator fault occurs, large estimation errors are generated by all filters except the one using the correct hypothesis. By monitoring the residual output of each filter, the specific fault that has occurred can be detected and isolated on the basis of the decision rules. A set of parameters that indicate the performance of the engine components is estimated by the "correct" Kalman filter for use in detecting component faults. To reduce the loss of diagnostic accuracy and sensitivity in the face of aging, the FDI system accepts information from a steady-state-condition-monitoring system. This information is used to update the Kalman filters and a data bank of trim values representative of the current aging condition.

Model-Based Control of an Aircraft Engine using an Optimal Tuner Approach

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Chicatelli, Amy; Garg, Sanjay

2012-01-01

This paper covers the development of a model-based engine control (MBEC) method- ology applied to an aircraft turbofan engine. Here, a linear model extracted from the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) at a cruise operating point serves as the engine and the on-board model. The on-board model is up- dated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. MBEC provides the ability for a tighter control bound of thrust over the entire life cycle of the engine that is not achievable using traditional control feedback, which uses engine pressure ratio or fan speed. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC tighter thrust control. In addition, investigations of using the MBEC to provide a surge limit for the controller limit logic are presented that could provide benefits over a simple acceleration schedule that is currently used in engine control architectures.

Cabin air filtration: helping to protect occupants from infectious diseases.

PubMed

Bull, Karen

2008-05-01

Presentation made at the Aviation Health Conference, London, November 2006. In modern aircraft, the air in the cabin is provided by the environmental control system (ECS) and consists of approximately 50% outside air (engine 'bleed air') mixed with approximately 50% filtered, recirculated air. This paper describes how modern aircraft cabin air filters are effective at removing airborne particulate contamination (such as bacteria and viruses) from the recirculated air system. It also describes one of the technological solutions that is currently available to treat any odours or volatile organic compounds (VOCs) that may be present in the aircraft ECS.

A Study on Application of Fuzzy Adaptive Unscented Kalman Filter to Nonlinear Turbojet Engine Control

NASA Astrophysics Data System (ADS)

Han, Dongju

2018-05-01

Safe and efficient flight powered by an aircraft turbojet engine relies on the performance of the engine controller preventing compressor surge with robustness from noises or disturbances. This paper proposes the effective nonlinear controller associated with the nonlinear filter for the real turbojet engine with highly nonlinear dynamics. For the feasible controller study the nonlinearity of the engine dynamics was investigated by comparing the step responses from the linearized model with the original nonlinear dynamics. The fuzzy-based PID control logic is introduced to control the engine efficiently and FAUKF is applied for robustness from noises. The simulation results prove the effectiveness of FAUKF applied to the proposed controller such that the control performances are superior over the conventional controller and the filer performance using FAUKF indicates the satisfactory results such as clearing the defects by reducing the distortions without compressor surge, whereas the conventional UKF is not fully effective as occurring some distortions with compressor surge due to a process noise.

Aircraft engine sensor fault diagnostics using an on-line OBEM update method.

PubMed

Liu, Xiaofeng; Xue, Naiyu; Yuan, Ye

2017-01-01

This paper proposed a method to update the on-line health reference baseline of the On-Board Engine Model (OBEM) to maintain the effectiveness of an in-flight aircraft sensor Fault Detection and Isolation (FDI) system, in which a Hybrid Kalman Filter (HKF) was incorporated. Generated from a rapid in-flight engine degradation, a large health condition mismatch between the engine and the OBEM can corrupt the performance of the FDI. Therefore, it is necessary to update the OBEM online when a rapid degradation occurs, but the FDI system will lose estimation accuracy if the estimation and update are running simultaneously. To solve this problem, the health reference baseline for a nonlinear OBEM was updated using the proposed channel controller method. Simulations based on the turbojet engine Linear-Parameter Varying (LPV) model demonstrated the effectiveness of the proposed FDI system in the presence of substantial degradation, and the channel controller can ensure that the update process finishes without interference from a single sensor fault.

Aircraft engine sensor fault diagnostics using an on-line OBEM update method

PubMed Central

Liu, Xiaofeng; Xue, Naiyu; Yuan, Ye

2017-01-01

This paper proposed a method to update the on-line health reference baseline of the On-Board Engine Model (OBEM) to maintain the effectiveness of an in-flight aircraft sensor Fault Detection and Isolation (FDI) system, in which a Hybrid Kalman Filter (HKF) was incorporated. Generated from a rapid in-flight engine degradation, a large health condition mismatch between the engine and the OBEM can corrupt the performance of the FDI. Therefore, it is necessary to update the OBEM online when a rapid degradation occurs, but the FDI system will lose estimation accuracy if the estimation and update are running simultaneously. To solve this problem, the health reference baseline for a nonlinear OBEM was updated using the proposed channel controller method. Simulations based on the turbojet engine Linear-Parameter Varying (LPV) model demonstrated the effectiveness of the proposed FDI system in the presence of substantial degradation, and the channel controller can ensure that the update process finishes without interference from a single sensor fault. PMID:28182692

Aircraft applications of fault detection and isolation techniques

NASA Astrophysics Data System (ADS)

Marcos Esteban, Andres

In this thesis the problems of fault detection & isolation and fault tolerant systems are studied from the perspective of LTI frequency-domain, model-based techniques. Emphasis is placed on the applicability of these LTI techniques to nonlinear models, especially to aerospace systems. Two applications of Hinfinity LTI fault diagnosis are given using an open-loop (no controller) design approach: one for the longitudinal motion of a Boeing 747-100/200 aircraft, the other for a turbofan jet engine. An algorithm formalizing a robust identification approach based on model validation ideas is also given and applied to the previous jet engine. A general linear fractional transformation formulation is given in terms of the Youla and Dual Youla parameterizations for the integrated (control and diagnosis filter) approach. This formulation provides better insight into the trade-off between the control and the diagnosis objectives. It also provides the basic groundwork towards the development of nested schemes for the integrated approach. These nested structures allow iterative improvements on the control/filter Youla parameters based on successive identification of the system uncertainty (as given by the Dual Youla parameter). The thesis concludes with an application of Hinfinity LTI techniques to the integrated design for the longitudinal motion of the previous Boeing 747-100/200 model.

Detection of respiratory viruses on air filters from aircraft.

PubMed

Korves, T M; Johnson, D; Jones, B W; Watson, J; Wolk, D M; Hwang, G M

2011-09-01

To evaluate the feasibility of identifying viruses from aircraft cabin air, we evaluated whether respiratory viruses trapped by commercial aircraft air filters can be extracted and detected using a multiplex PCR, bead-based assay. The ResPlex II assay was first tested for its ability to detect inactivated viruses applied to new filter material; all 18 applications of virus at a high concentration were detected. The ResPlex II assay was then used to test for 18 respiratory viruses on 48 used air filter samples from commercial aircraft. Three samples tested positive for viruses, and three viruses were detected: rhinovirus, influenza A and influenza B. For 33 of 48 samples, internal PCR controls performed suboptimally, suggesting sample matrix effect. In some cases, influenza and rhinovirus RNA can be detected on aircraft air filters, even more than 10 days after the filters were removed from aircraft. With protocol modifications to overcome PCR inhibition, air filter sampling and the ResPlex II assay could be used to characterize viruses in aircraft cabin air. Information about viruses in aircraft could support public health measures to reduce disease transmission within aircraft and between cities. © The MITRE corporation. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

A computer program to obtain time-correlated gust loads for nonlinear aircraft using the matched-filter-based method

NASA Technical Reports Server (NTRS)

Scott, Robert C.; Pototzky, Anthony S.; Perry, Boyd, III

1994-01-01

NASA Langley Research Center has, for several years, conducted research in the area of time-correlated gust loads for linear and nonlinear aircraft. The results of this work led NASA to recommend that the Matched-Filter-Based One-Dimensional Search Method be used for gust load analyses of nonlinear aircraft. This manual describes this method, describes a FORTRAN code which performs this method, and presents example calculations for a sample nonlinear aircraft model. The name of the code is MFD1DS (Matched-Filter-Based One-Dimensional Search). The program source code, the example aircraft equations of motion, a sample input file, and a sample program output are all listed in the appendices.

Eddy current testing for blade edge micro cracks of aircraft engine

NASA Astrophysics Data System (ADS)

Zhang, Wei-min; Xu, Min-dong; Gao, Xuan-yi; Jin, Xin; Qin, Feng

2017-10-01

Based on the problems of low detection efficiency in the micro cracks detection of aircraft engine blades, a differential excitation eddy current testing system was designed and developed. The function and the working principle of the system were described, the problems which contained the manufacture method of simulated cracks, signal generating, signal processing and the signal display method were described. The detection test was carried out by taking a certain model aircraft engine blade with simulated cracks as a tested specimen. The test data was processed by digital low-pass filter in the computer and the crack signals of time domain display and Lissajous figure display were acquired. By comparing the test results, it is verified that Lissajous figure display shows better performance compared to time domain display when the crack angle is small. The test results show that the eddy current testing system designed in this paper is feasible to detect the micro cracks on the aeroengine blade and can effectively improve the detection efficiency of micro cracks in the practical detection work.

A preliminary evaluation of an F100 engine parameter estimation process using flight data

NASA Technical Reports Server (NTRS)

Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

1990-01-01

The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the compact engine model (CEM). In this step, the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion control law development.

A preliminary evaluation of an F100 engine parameter estimation process using flight data

NASA Technical Reports Server (NTRS)

Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

1990-01-01

The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the 'compact engine model' (CEM). In this step the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion-control-law development.

A simple dynamic engine model for use in a real-time aircraft simulation with thrust vectoring

NASA Technical Reports Server (NTRS)

Johnson, Steven A.

1990-01-01

A simple dynamic engine model was developed at the NASA Ames Research Center, Dryden Flight Research Facility, for use in thrust vectoring control law development and real-time aircraft simulation. The simple dynamic engine model of the F404-GE-400 engine (General Electric, Lynn, Massachusetts) operates within the aircraft simulator. It was developed using tabular data generated from a complete nonlinear dynamic engine model supplied by the manufacturer. Engine dynamics were simulated using a throttle rate limiter and low-pass filter. Included is a description of a method to account for axial thrust loss resulting from thrust vectoring. In addition, the development of the simple dynamic engine model and its incorporation into the F-18 high alpha research vehicle (HARV) thrust vectoring simulation. The simple dynamic engine model was evaluated at Mach 0.2, 35,000 ft altitude and at Mach 0.7, 35,000 ft altitude. The simple dynamic engine model is within 3 percent of the steady state response, and within 25 percent of the transient response of the complete nonlinear dynamic engine model.

Determination of tricresyl phosphate air contamination in aircraft.

PubMed

Denola, G; Hanhela, P J; Mazurek, W

2011-08-01

Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse.

A Systematic Approach to Sensor Selection for Aircraft Engine Health Estimation

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Garg, Sanjay

2009-01-01

A systematic approach for selecting an optimal suite of sensors for on-board aircraft gas turbine engine health estimation is presented. The methodology optimally chooses the engine sensor suite and the model tuning parameter vector to minimize the Kalman filter mean squared estimation error in the engine s health parameters or other unmeasured engine outputs. This technique specifically addresses the underdetermined estimation problem where there are more unknown system health parameters representing degradation than available sensor measurements. This paper presents the theoretical estimation error equations, and describes the optimization approach that is applied to select the sensors and model tuning parameters to minimize these errors. Two different model tuning parameter vector selection approaches are evaluated: the conventional approach of selecting a subset of health parameters to serve as the tuning parameters, and an alternative approach that selects tuning parameters as a linear combination of all health parameters. Results from the application of the technique to an aircraft engine simulation are presented, and compared to those from an alternative sensor selection strategy.

Global civil aviation black carbon emissions.

PubMed

Stettler, Marc E J; Boies, Adam M; Petzold, Andreas; Barrett, Steven R H

2013-09-17

Aircraft black carbon (BC) emissions contribute to climate forcing, but few estimates of BC emitted by aircraft at cruise exist. For the majority of aircraft engines the only BC-related measurement available is smoke number (SN)-a filter based optical method designed to measure near-ground plume visibility, not mass. While the first order approximation (FOA3) technique has been developed to estimate BC mass emissions normalized by fuel burn [EI(BC)] from SN, it is shown that it underestimates EI(BC) by >90% in 35% of directly measured cases (R(2) = -0.10). As there are no plans to measure BC emissions from all existing certified engines-which will be in service for several decades-it is necessary to estimate EI(BC) for existing aircraft on the ground and at cruise. An alternative method, called FOX, that is independent of the SN is developed to estimate BC emissions. Estimates of EI(BC) at ground level are significantly improved (R(2) = 0.68), whereas estimates at cruise are within 30% of measurements. Implementing this approach for global civil aviation estimated aircraft BC emissions are revised upward by a factor of ~3. Direct radiative forcing (RF) due to aviation BC emissions is estimated to be ~9.5 mW/m(2), equivalent to ~1/3 of the current RF due to aviation CO2 emissions.

Oil cooling system for a gas turbine engine

NASA Technical Reports Server (NTRS)

Coffinberry, G. A.; Kast, H. B. (Inventor)

1977-01-01

A gas turbine engine fuel delivery and control system is provided with means to recirculate all fuel in excess fuel control requirements back to the aircraft fuel tank. This increases the fuel pump heat sink and decreases the pump temperature rise without the addition of valving other than normally employed. A fuel/oil heat exchanger and associated circuitry is provided to maintain the hot engine oil in heat exchange relationship with the cool engine fuel. Where anti-icing of the fuel filter is required, means are provided to maintain the fuel temperature entering the filter at or above a minimum level to prevent freezing thereof. In one embodiment, a divider valve is provided to take all excess fuel from either upstream or downstream of the fuel filter and route it back to the tanks, the ratio of upstream to downstream extraction being a function of fuel pump discharge pressure.

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

CFD analysis of turboprop engine oil cooler duct for best rate of climb condition

NASA Astrophysics Data System (ADS)

Kalia, Saurabh; CA, Vinay; Hegde, Suresh M.

2016-09-01

Turboprop engines are widely used in commuter category airplanes. Aircraft Design bureaus routinely conduct the flight tests to confirm the performance of the system. The lubrication system of the engine is designed to provide a constant supply of clean lubrication oil to the engine bearings, the reduction gears, the torque-meter, the propeller and the accessory gearbox. The oil lubricates, cools and also conducts foreign material to the oil filter where it is removed from further circulation. Thus a means of cooling the engine oil must be provided and a suitable oil cooler (OC) and ducting system was selected and designed for this purpose. In this context, it is relevant to study and analyse behaviour of the engine oil cooler system before commencing actual flight tests. In this paper, the performance of the oil cooler duct with twin flush NACA inlet housed inside the nacelle has been studied for aircraft best rate of climb (ROC) condition using RANS based SST K-omega model by commercial software ANSYS Fluent 13.0. From the CFD analysis results, it is found that the mass flow rate captured and pressure drop across the oil cooler for the best ROC condition is meeting the oil cooler manufacturer requirements thus, the engine oil temperature is maintained within prescribed limits.

Oil cooling system for a gas turbine engine

NASA Technical Reports Server (NTRS)

Coffinberry, G. A.; Kast, H. B. (Inventor)

1977-01-01

A gas turbine engine fuel delivery and control system is provided with means to recirculate all fuel in excess of fuel control requirements back to aircraft fuel tank, thereby increasing the fuel pump heat sink and decreasing the pump temperature rise without the addition of valving other than that normally employed. A fuel/oil heat exchanger and associated circuitry is provided to maintain the hot engine oil in heat exchange relationship with the cool engine fuel. Where anti-icing of the fuel filter is required, means are provided to maintain the fuel temperature entering the filter at or above a minimum level to prevent freezing thereof. Fluid circuitry is provided to route hot engine oil through a plurality of heat exchangers disposed within the system to provide for selective cooling of the oil.

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

Fine particle and organic vapor emissions from staged tests of an in-use aircraft engine

NASA Astrophysics Data System (ADS)

Presto, Albert A.; Nguyen, Ngoc T.; Ranjan, Manish; Reeder, Aaron J.; Lipsky, Eric M.; Hennigan, Christopher J.; Miracolo, Marissa A.; Riemer, Daniel D.; Robinson, Allen L.

2011-07-01

Staged tests were conducted to measure the particle and vapor emissions from a CFM56-2B1 gas-turbine engine mounted on a KC-135T Stratotanker airframe at different engine loads. Exhaust was sampled using a rake inlet installed 1-m downstream of the engine exit plane of a parked and chocked aircraft and a dilution sampler and portable smog chamber were used to investigate the particulate matter (PM) emissions. Total fine PM mass emissions were highest at low (4%) and high (85%) load and lower at intermediate loads (7% and 30%). PM mass emissions at 4% load are dominated by organics, while at 85% load elemental carbon is dominant. Quantifying the primary organic aerosol (POA) emissions is complicated by substantial filter sampling artifacts. Partitioning experiments reveal that the majority of the POA is semivolatile; for example, the POA emission factor changed by a factor of two when the background organic aerosol concentration was increased from 0.7 to 4 μg m -3. Therefore, one cannot define a single non-volatile PM emission factor for aircraft exhaust. The gas- and particle-phase organic emissions were comprehensively characterized by analyzing canister, sorbent and filter samples with gas-chromatography/mass-spectrometry. Vapor-phase organic emissions are highest at 4% load and decrease with increasing load. Low-volatility organics (less volatile than a C 12n-alkane) contributed 10-20% of the total organic emissions. The low-volatility organic emissions contain signatures of unburned fuel and aircraft lubricating oil but are dominated by an unresolved complex mixture (UCM) of presumably branched and cyclic alkanes. Emissions at all loads contain more low-volatility organic vapors than POA; thus secondary organic aerosol formation in the aging plume will likely exceed POA emissions.

75 FR 70098 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY...: This Airworthiness Directive (AD) results from reports of cracks in the engine crankcase. Austro... crankcase assembly has permitted to reduce applicability of the new AD, when based on engines' serial...

Sensor Selection for Aircraft Engine Performance Estimation and Gas Path Fault Diagnostics

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan W.

2015-01-01

This paper presents analytical techniques for aiding system designers in making aircraft engine health management sensor selection decisions. The presented techniques, which are based on linear estimation and probability theory, are tailored for gas turbine engine performance estimation and gas path fault diagnostics applications. They enable quantification of the performance estimation and diagnostic accuracy offered by different candidate sensor suites. For performance estimation, sensor selection metrics are presented for two types of estimators including a Kalman filter and a maximum a posteriori estimator. For each type of performance estimator, sensor selection is based on minimizing the theoretical sum of squared estimation errors in health parameters representing performance deterioration in the major rotating modules of the engine. For gas path fault diagnostics, the sensor selection metric is set up to maximize correct classification rate for a diagnostic strategy that performs fault classification by identifying the fault type that most closely matches the observed measurement signature in a weighted least squares sense. Results from the application of the sensor selection metrics to a linear engine model are presented and discussed. Given a baseline sensor suite and a candidate list of optional sensors, an exhaustive search is performed to determine the optimal sensor suites for performance estimation and fault diagnostics. For any given sensor suite, Monte Carlo simulation results are found to exhibit good agreement with theoretical predictions of estimation and diagnostic accuracies.

Sensor Selection for Aircraft Engine Performance Estimation and Gas Path Fault Diagnostics

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan W.

2016-01-01

This paper presents analytical techniques for aiding system designers in making aircraft engine health management sensor selection decisions. The presented techniques, which are based on linear estimation and probability theory, are tailored for gas turbine engine performance estimation and gas path fault diagnostics applications. They enable quantification of the performance estimation and diagnostic accuracy offered by different candidate sensor suites. For performance estimation, sensor selection metrics are presented for two types of estimators including a Kalman filter and a maximum a posteriori estimator. For each type of performance estimator, sensor selection is based on minimizing the theoretical sum of squared estimation errors in health parameters representing performance deterioration in the major rotating modules of the engine. For gas path fault diagnostics, the sensor selection metric is set up to maximize correct classification rate for a diagnostic strategy that performs fault classification by identifying the fault type that most closely matches the observed measurement signature in a weighted least squares sense. Results from the application of the sensor selection metrics to a linear engine model are presented and discussed. Given a baseline sensor suite and a candidate list of optional sensors, an exhaustive search is performed to determine the optimal sensor suites for performance estimation and fault diagnostics. For any given sensor suite, Monte Carlo simulation results are found to exhibit good agreement with theoretical predictions of estimation and diagnostic accuracies.

Data-driven fault detection, isolation and estimation of aircraft gas turbine engine actuator and sensors

NASA Astrophysics Data System (ADS)

Naderi, E.; Khorasani, K.

2018-02-01

In this work, a data-driven fault detection, isolation, and estimation (FDI&E) methodology is proposed and developed specifically for monitoring the aircraft gas turbine engine actuator and sensors. The proposed FDI&E filters are directly constructed by using only the available system I/O data at each operating point of the engine. The healthy gas turbine engine is stimulated by a sinusoidal input containing a limited number of frequencies. First, the associated system Markov parameters are estimated by using the FFT of the input and output signals to obtain the frequency response of the gas turbine engine. These data are then used for direct design and realization of the fault detection, isolation and estimation filters. Our proposed scheme therefore does not require any a priori knowledge of the system linear model or its number of poles and zeros at each operating point. We have investigated the effects of the size of the frequency response data on the performance of our proposed schemes. We have shown through comprehensive case studies simulations that desirable fault detection, isolation and estimation performance metrics defined in terms of the confusion matrix criterion can be achieved by having access to only the frequency response of the system at only a limited number of frequencies.

75 FR 28504 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY... reports of cracks in the engine crankcase. Austro Control GmbH (ACG) addressed the problem by issuing AD... applicability of the new AD, when based on engines' serial numbers (s/n). On the other hand, applicability is...

Sea-Based Automated Launch and Recovery System Virtual Testbed

DTIC Science & Technology

2013-12-02

integrated with an Extended Kalman Filter to study sensor fusion in a fixed wing aircraft shipboard recovery scenario. 15. SUBJECT TERMS...the sensors and filter performance are graded both on pure estimation error, and by examining the touchdown performance of the aircraft on the ship...v, and w body-axis velocity components of the aircraft , while the velocities applied to the extremities are used to calculate estimated rotational

A proposed Kalman filter algorithm for estimation of unmeasured output variables for an F100 turbofan engine

NASA Technical Reports Server (NTRS)

Alag, Gurbux S.; Gilyard, Glenn B.

1990-01-01

To develop advanced control systems for optimizing aircraft engine performance, unmeasurable output variables must be estimated. The estimation has to be done in an uncertain environment and be adaptable to varying degrees of modeling errors and other variations in engine behavior over its operational life cycle. This paper represented an approach to estimate unmeasured output variables by explicitly modeling the effects of off-nominal engine behavior as biases on the measurable output variables. A state variable model accommodating off-nominal behavior is developed for the engine, and Kalman filter concepts are used to estimate the required variables. Results are presented from nonlinear engine simulation studies as well as the application of the estimation algorithm on actual flight data. The formulation presented has a wide range of application since it is not restricted or tailored to the particular application described.

Pollutant monitoring of aircraft exhaust with multispectral imaging

NASA Astrophysics Data System (ADS)

Berkson, Emily E.; Messinger, David W.

2016-10-01

Communities surrounding local airports are becoming increasingly concerned about the aircraft pollutants emitted during the landing-takeoff (LTO) cycle, and their potential for negative health effects. Chicago, Los Angeles, Boston and London have all recently been featured in the news regarding concerns over the amount of airport pollution being emitted on a daily basis, and several studies have been published on the increased risks of cancer for those living near airports. There are currently no inexpensive, portable, and unobtrusive sensors that can monitor the spatial and temporal nature of jet engine exhaust plumes. In this work we seek to design a multispectral imaging system that is capable of tracking exhaust plumes during the engine idle phase, with a specific focus on unburned hydrocarbon (UHC) emissions. UHCs are especially potent to local air quality, and their strong absorption features allow them to act as a spatial and temporal plume tracer. Using a Gaussian plume to radiometrically model jet engine exhaust, we have begun designing an inexpensive, portable, and unobtrusive imaging system to monitor the relative amount of pollutants emitted by aircraft in the idle phase. The LWIR system will use two broadband filters to detect emitted UHCs. This paper presents the spatial and temporal radiometric models of the exhaust plume from a typical jet engine used on 737s. We also select filters for plume tracking, and propose an imaging system layout for optimal detectibility. In terms of feasibility, a multispectral imaging system will be two orders of magnitude cheaper than current unobtrusive methods (PTR-MS) used to monitor jet engine emissions. Large-scale impacts of this work will include increased capabilities to monitor local airport pollution, and the potential for better-informed decision-making regarding future developments to airports.

The implementation and operation of a variable-response electronic throttle control system for a TF-104G aircraft

NASA Technical Reports Server (NTRS)

Neal, Bradford; Sengupta, Upal

1989-01-01

During some flight programs, researchers have encountered problems in the throttle response characteristics of high-performance aircraft. To study and to help solve these problems, the National Aeronautics and Space Administration Ames Research Center's Dryden Flight Research Facility (Ames-Dryden) conducted a study using a TF-104G airplane modified with a variable-response electronic throttle control system. Ames-Dryden investigated the effects of different variables on engine response and handling qualities. The system provided transport delay, lead and lag filters, second-order lags, command rate and position limits, and variable gain between the pilot's throttle command and the engine fuel controller. These variables could be tested individually or in combination. Ten research flights were flown to gather data on engine response and to obtain pilot ratings of the various system configurations. The results should provide design criteria for engine-response characteristics. The variable-response throttle components and how they were installed in the TF-104G aircraft are described. How the variable-response throttle was used in flight and some of the results of using this system are discussed.

Techniques for noise removal and registration of TIMS data

USGS Publications Warehouse

Hummer-Miller, S.

1990-01-01

Extracting subtle differences from highly correlated thermal infrared aircraft data is possible with appropriate noise filters, constructed and applied in the spatial frequency domain. This paper discusses a heuristic approach to designing noise filters for removing high- and low-spatial frequency striping and banding. Techniques for registering thermal infrared aircraft data to a topographic base using Thematic Mapper data are presented. The noise removal and registration techniques are applied to TIMS thermal infrared aircraft data. -Author

AGARD Flight Test Techniques Series. Volume 14. Introduction to Flight Test Engineering (Introduction a la Technique d’essais en vol)

DTIC Science & Technology

1995-09-01

path and aircraft attitude and other flight or aircraft parameters • Calculations in the frequency domain ( Fast Fourier Transform) • Data analysis...Signal filtering Image processing of video and radar data Parameter identification Statistical analysis Power spectral density Fast Fourier Transform...airspeeds both fast and slow, altitude, load factor both above and below 1g, centers of gravity (fore and aft), and with system/subsystem failures. Whether

Development of an Unmanned Aircraft Systems Program: ACUASI

NASA Astrophysics Data System (ADS)

Webley, P. W.; Cahill, C. F.; Rogers, M.; Hatfield, M. C.

2017-12-01

The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) has developed a comprehensive program that incorporates pilots, flight/mission planners, geoscientists, university undergraduate and graduate students, and engineers together as one. We lead and support unmanned aircraft system (UAS) missions for geoscience research, emergency response, humanitarian needs, engineering design, and policy development. We are the University of Alaska's UAS research program, lead the Federal Aviation Administration (FAA) Pan-Pacific UAS Test Range Complex (PPUTRC) with Hawaii, Oregon, and Mississippi and in 2015 became a core member of the FAA Center of Excellence for UAS Research, managed by Mississippi State University. ACUASI's suite of aircraft include small hand-launched/vertical take-off and landing assets for short-term rapid deployment to large fixed-wing gas powered systems that provide multiple hours of flight time. We have extensive experience in Arctic and sub-Arctic environments and will present on how we have used our aircraft and payloads in numerous missions that include beyond visual line of sight flights, mapping the river ice-hazard in Alaska during spring break-up, and providing UAS-based observations for local Alaskans to navigate through the changing ice shelf of Northern Alaska. Several sensor developments of interest in the near future include building payloads for thermal infrared mapping at high spatial resolutions, combining forward and nadir looking cameras on the same UAS aircraft for topographic mapping, and using neutral density and narrow band filters to map very high temperature thermally active hazards, such as forest fires and volcanic eruptions. The ACUASI team working together provide us the experience, tools, capabilities, and personnel to build and maintain a world class research center for unmanned aircraft systems as well as support both real-time operations and geoscience research.

Attitude algorithm and initial alignment method for SINS applied in short-range aircraft

NASA Astrophysics Data System (ADS)

Zhang, Rong-Hui; He, Zhao-Cheng; You, Feng; Chen, Bo

2017-07-01

This paper presents an attitude solution algorithm based on the Micro-Electro-Mechanical System and quaternion method. We completed the numerical calculation and engineering practice by adopting fourth-order Runge-Kutta algorithm in the digital signal processor. The state space mathematical model of initial alignment in static base was established, and the initial alignment method based on Kalman filter was proposed. Based on the hardware in the loop simulation platform, the short-range flight simulation test and the actual flight test were carried out. The results show that the error of pitch, yaw and roll angle is fast convergent, and the fitting rate between flight simulation and flight test is more than 85%.

Ethanol content concerns in motor gasoline (mogas) in aviation in comparison to aviation gasoline (avgas)

NASA Astrophysics Data System (ADS)

Thanikasalam, K.; Rahmat, M.; Fahmi, A. G. Mohammad; Zulkifli, A. M.; Shawal, N. Noor; Ilanchelvi, K.; Ananth, M.; Elayarasan, R.

2018-05-01

Mogas has been an alternative to leaded fuel since 1964 when Experimental Aircraft Association (EAA) began testing on it. However, in order for mogas to be used in aircraft engines and air frame modification, approval via the Supplemental Type Certificate (STC) authorization from Federal Aviation Administration (FAA) is mandatory. Cessna on 01.06.2010 evaluated alternative fuels with ethanol based fuels approved by FAA STCs for use in some single engine airplanes. However, Cessna’s tests discovered that ethanol based gasoline cannot be viewed as an option to 100LL avgas. The test likewise proposed that operational safety might be in jeopardy if usage of these fuels containing ethanol is continued. Cessna outlined a few problems in MOGAS; MOGAS needs fuel flow increase of 40% compared to AVGAS, MOGAS fuel is incompatible with some fuel system components, possible hazardous influence of electric fuel pumps by adding internal wear causing unexpected spark generation, MOGAS is incompatible with some fuel gauging systems and cause be able to incorrect fuel amount signs on the indicator, dissolve large amounts of water at conditions down to -77°F, impeding detection and removal of water from the fuel system, possible blockage of fuel filters and fuel flow and possible heavy losses from evaporation. This paper reviews concerns when using MOGAS in aircraft.

Advanced Control Considerations for Turbofan Engine Design

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy

2016-01-01

This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner Kalman Filter estimation routine, which enables the on-board model to self-tune to account for engine performance variations. MBEC is used here to show how advanced control architectures can improve efficiency during the design phase of a turbofan engine by reducing conservative operability margins. The operability margins that can be reduced, such as stall margin, can expand the engine design space and offer potential for efficiency improvements. Application of MBEC architecture to a nonlinear engine simulation is shown to reduce the thrust specific fuel consumption by approximately 1% over the baseline design, while maintaining safe operation of the engine across the flight envelope.

Evaluation of methods for measuring particulate matter emissions from gas turbines.

PubMed

Petzold, Andreas; Marsh, Richard; Johnson, Mark; Miller, Michael; Sevcenco, Yura; Delhaye, David; Ibrahim, Amir; Williams, Paul; Bauer, Heidi; Crayford, Andrew; Bachalo, William D; Raper, David

2011-04-15

The project SAMPLE evaluated methods for measuring particle properties in the exhaust of aircraft engines with respect to the development of standardized operation procedures for particulate matter measurement in aviation industry. Filter-based off-line mass methods included gravimetry and chemical analysis of carbonaceous species by combustion methods. Online mass methods were based on light absorption measurement or used size distribution measurements obtained from an electrical mobility analyzer approach. Number concentrations were determined using different condensation particle counters (CPC). Total mass from filter-based methods balanced gravimetric mass within 8% error. Carbonaceous matter accounted for 70% of gravimetric mass while the remaining 30% were attributed to hydrated sulfate and noncarbonaceous organic matter fractions. Online methods were closely correlated over the entire range of emission levels studied in the tests. Elemental carbon from combustion methods and black carbon from optical methods deviated by maximum 5% with respect to mass for low to medium emission levels, whereas for high emission levels a systematic deviation between online methods and filter based methods was found which is attributed to sampling effects. CPC based instruments proved highly reproducible for number concentration measurements with a maximum interinstrument standard deviation of 7.5%.

Aircraft Hydraulic System Leakage Detection and Servicing Recommendations Method

DTIC Science & Technology

2014-10-02

2008), Modelagem e Análise do Sistema Hidráulico de uma Aeronave Comercial Regional. M.Sc. Thesis. Instituto Tecnológico de Aeronáutica, São José...degree in Control Engineering from Universidade Estadual de Campinas (Unicamp, 2004), Brazil, and a Master Degree in Aeronautical Engineering from...accumulators, filters, and consumers, that include all the actuators connected to the hydraulic power such as flight controls , brake and landing

Aircraft Engine Thrust Estimator Design Based on GSA-LSSVM

NASA Astrophysics Data System (ADS)

Sheng, Hanlin; Zhang, Tianhong

2017-08-01

In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.

A Novel Modeling Method for Aircraft Engine Using Nonlinear Autoregressive Exogenous (NARX) Models Based on Wavelet Neural Networks

NASA Astrophysics Data System (ADS)

Yu, Bing; Shu, Wenjun; Cao, Can

2018-05-01

A novel modeling method for aircraft engine using nonlinear autoregressive exogenous (NARX) models based on wavelet neural networks is proposed. The identification principle and process based on wavelet neural networks are studied, and the modeling scheme based on NARX is proposed. Then, the time series data sets from three types of aircraft engines are utilized to build the corresponding NARX models, and these NARX models are validated by the simulation. The results show that all the best NARX models can capture the original aircraft engine's dynamic characteristic well with the high accuracy. For every type of engine, the relative identification errors of its best NARX model and the component level model are no more than 3.5 % and most of them are within 1 %.

Aircraft Engine On-Line Diagnostics Through Dual-Channel Sensor Measurements: Development of an Enhanced System

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2008-01-01

In this paper, an enhanced on-line diagnostic system which utilizes dual-channel sensor measurements is developed for the aircraft engine application. The enhanced system is composed of a nonlinear on-board engine model (NOBEM), the hybrid Kalman filter (HKF) algorithm, and fault detection and isolation (FDI) logic. The NOBEM provides the analytical third channel against which the dual-channel measurements are compared. The NOBEM is further utilized as part of the HKF algorithm which estimates measured engine parameters. Engine parameters obtained from the dual-channel measurements, the NOBEM, and the HKF are compared against each other. When the discrepancy among the signals exceeds a tolerance level, the FDI logic determines the cause of discrepancy. Through this approach, the enhanced system achieves the following objectives: 1) anomaly detection, 2) component fault detection, and 3) sensor fault detection and isolation. The performance of the enhanced system is evaluated in a simulation environment using faults in sensors and components, and it is compared to an existing baseline system.

Physical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions Experiment (APEX) 1 to 3

EPA Science Inventory

The f1me particulate matter (PM) emissions from nine commercial aircraft engine models were determined by plume sampling during the three field campaigns of the Aircraft Particle Emissions Experiment (APEX). Ground-based measurements were made primarily at 30 m behind the engine ...

STOL propulsion systems

NASA Technical Reports Server (NTRS)

Denington, R. J.; Koenig, R. W.; Vanco, M. R.; Sagerser, D. A.

1972-01-01

The selection and the characteristics of quiet, clean propulsion systems for STOL aircraft are discussed. Engines are evaluated for augmentor wing and externally blown flap STOL aircraft with the engines located both under and over the wings. Some supporting test data are presented. Optimum engines are selected based on achieving the performance, economic, acoustic, and pollution goals presently being considered for future STOL aircraft. The data and results presented were obtained from a number of contracted studies and some supporting NASA inhouse programs, most of which began in early 1972. The contracts include: (1) two aircraft and mission studies, (2) two propulsion system studies, (3) the experimental and analytic work on the augmentor wing, and (4) the experimental programs on Q-Fan. Engines are selected and discussed based on aircraft economics using the direct operating cost as the primary criterion. This cost includes the cost of the crew, fuel, aircraft, and engine maintenance and depreciation.

Multi-Sensor Fusion with Interacting Multiple Model Filter for Improved Aircraft Position Accuracy

PubMed Central

Cho, Taehwan; Lee, Changho; Choi, Sangbang

2013-01-01

The International Civil Aviation Organization (ICAO) has decided to adopt Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) as the 21st century standard for navigation. Accordingly, ICAO members have provided an impetus to develop related technology and build sufficient infrastructure. For aviation surveillance with CNS/ATM, Ground-Based Augmentation System (GBAS), Automatic Dependent Surveillance-Broadcast (ADS-B), multilateration (MLAT) and wide-area multilateration (WAM) systems are being established. These sensors can track aircraft positions more accurately than existing radar and can compensate for the blind spots in aircraft surveillance. In this paper, we applied a novel sensor fusion method with Interacting Multiple Model (IMM) filter to GBAS, ADS-B, MLAT, and WAM data in order to improve the reliability of the aircraft position. Results of performance analysis show that the position accuracy is improved by the proposed sensor fusion method with the IMM filter. PMID:23535715

Multi-sensor fusion with interacting multiple model filter for improved aircraft position accuracy.

PubMed

Cho, Taehwan; Lee, Changho; Choi, Sangbang

2013-03-27

The International Civil Aviation Organization (ICAO) has decided to adopt Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) as the 21st century standard for navigation. Accordingly, ICAO members have provided an impetus to develop related technology and build sufficient infrastructure. For aviation surveillance with CNS/ATM, Ground-Based Augmentation System (GBAS), Automatic Dependent Surveillance-Broadcast (ADS-B), multilateration (MLAT) and wide-area multilateration (WAM) systems are being established. These sensors can track aircraft positions more accurately than existing radar and can compensate for the blind spots in aircraft surveillance. In this paper, we applied a novel sensor fusion method with Interacting Multiple Model (IMM) filter to GBAS, ADS-B, MLAT, and WAM data in order to improve the reliability of the aircraft position. Results of performance analysis show that the position accuracy is improved by the proposed sensor fusion method with the IMM filter.

Differences in Characteristics of Aviation Accidents During 1993-2012 Based on Aircraft Type

NASA Technical Reports Server (NTRS)

Evans, Joni K.

2015-01-01

Civilian aircraft are available in a variety of sizes, engine types, construction materials and instrumentation complexity. For the analysis reported here, eleven aircraft categories were developed based mostly on aircraft size and engine type, and these categories were applied to twenty consecutive years of civil aviation accidents. Differences in various factors were examined among these aircraft types, including accident severity, pilot characteristics and accident occurrence categories. In general, regional jets and very light sport aircraft had the lowest rates of adverse outcomes (injuries, fatal accidents, aircraft destruction, major accidents), while aircraft with twin (piston) engines or with a single (piston) engine and retractable landing gear carried the highest incidence of adverse outcomes. The accident categories of abnormal runway contact, runway excursions and non-powerplant system/component failures occur frequently within all but two or three aircraft types. In contrast, ground collisions, loss of control - on ground/water and powerplant system/component failure occur frequently within only one or two aircraft types. Although accidents in larger aircraft tend to have less severe outcomes, adverse outcome rates also differ among accident categories. It may be that the type of accident has as much or more influence on the outcome as the type of aircraft.

Study of unconventional aircraft engines designed for low energy consumption

NASA Technical Reports Server (NTRS)

Gray, D. E.

1976-01-01

Declining U.S. oil reserves and escalating energy costs underline the need for reducing fuel consumption in aircraft engines. The most promising unconventional aircraft engines based on their potential for fuel savings and improved economics are identified. The engines installed in both a long-range and medium-range aircraft were evaluated. Projected technology advances are identified and evaluated for their state-of-readiness for application to a commercial transport. Programs are recommended for developing the necessary technology.

Model-Based Fault Tolerant Control

NASA Technical Reports Server (NTRS)

Kumar, Aditya; Viassolo, Daniel

2008-01-01

The Model Based Fault Tolerant Control (MBFTC) task was conducted under the NASA Aviation Safety and Security Program. The goal of MBFTC is to develop and demonstrate real-time strategies to diagnose and accommodate anomalous aircraft engine events such as sensor faults, actuator faults, or turbine gas-path component damage that can lead to in-flight shutdowns, aborted take offs, asymmetric thrust/loss of thrust control, or engine surge/stall events. A suite of model-based fault detection algorithms were developed and evaluated. Based on the performance and maturity of the developed algorithms two approaches were selected for further analysis: (i) multiple-hypothesis testing, and (ii) neural networks; both used residuals from an Extended Kalman Filter to detect the occurrence of the selected faults. A simple fusion algorithm was implemented to combine the results from each algorithm to obtain an overall estimate of the identified fault type and magnitude. The identification of the fault type and magnitude enabled the use of an online fault accommodation strategy to correct for the adverse impact of these faults on engine operability thereby enabling continued engine operation in the presence of these faults. The performance of the fault detection and accommodation algorithm was extensively tested in a simulation environment.

Adaptive Failure Compensation for Aircraft Tracking Control Using Engine Differential Based Model

NASA Technical Reports Server (NTRS)

Liu, Yu; Tang, Xidong; Tao, Gang; Joshi, Suresh M.

2006-01-01

An aircraft model that incorporates independently adjustable engine throttles and ailerons is employed to develop an adaptive control scheme in the presence of actuator failures. This model captures the key features of aircraft flight dynamics when in the engine differential mode. Based on this model an adaptive feedback control scheme for asymptotic state tracking is developed and applied to a transport aircraft model in the presence of two types of failures during operation, rudder failure and aileron failure. Simulation results are presented to demonstrate the adaptive failure compensation scheme.

Easy method of matching fighter engine to airframe for use in aircraft engine design courses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattingly, J.D.

1989-01-01

The proper match of the engine(s) to the airframe affects both aircraft size and life cycle cost. A fast and straightforward method is developed and used for the matching of fighter engine(s) to airframes during conceptual design. A thrust-lapse equation is developed for the dual-spool, mixed-flow, afterburning turbofan type of engine based on the installation losses of 'Aircraft Engine Design' and the performance predictions of the cycle analysis programs ONX and OFFX. Using system performance requirements, the effects of aircraft thrust-to-weight, wing loading, and engine cycle on takeoff weight are analyzed and example design course results presented. 5 refs.

Response to actual and simulated recordings of conventional takeoff and landing jet aircraft

NASA Technical Reports Server (NTRS)

Mabry, J. E.; Sullivan, B. M.

1978-01-01

Comparability between noise characteristics of synthesized recordings of aircraft in flight and actual recordings were investigated. Although the synthesized recordings were more smoothly time-varying than the actual recordings and the synthesizer could not produce a comb-filter effect that was present in the actual recordings, results supported the conclusion that annoyance response is comparable to the synthesized and actual recordings. A correction for duration markedly improved the validity of engineering calculation procedures designed to measure noise annoyance. Results led to the conclusion that the magnitude estimation psychophysical method was a highly reliable approach for evaluating engineering calculation procedures designed to measure noise annoyance. For repeated presentations of pairs of actual recordings, differences between judgment results for identical signals ranged from 0.0 to 0.5 db.

Licencing and Training Reform in the Australian Aircraft Maintenance Industry

ERIC Educational Resources Information Center

Hampson, Ian; Fraser, Doug

2016-01-01

The training and licencing of aircraft maintenance engineers fulfils a crucial protective function since it is they who perform and supervise aircraft maintenance and certify that planes are safe afterwards. In Australia, prior to training reform, a trades-based system of aircraft maintenance engineer training existed in an orderly relation with…

Microstructure Based Material-Sand Particulate Interactions and Assessment of Coatings for High Temperature Turbine Blades

NASA Technical Reports Server (NTRS)

Murugan, Muthuvel; Ghoshal, Anindya; Walock, Michael; Nieto, Andy; Bravo, Luis; Barnett, Blake; Pepi, Marc; Swab, Jeffrey; Pegg, Robert Tyler; Rowe, Chris;

A New Formulation of the Filter-Error Method for Aerodynamic Parameter Estimation in Turbulence

NASA Technical Reports Server (NTRS)

Grauer, Jared A.; Morelli, Eugene A.

2015-01-01

A new formulation of the filter-error method for estimating aerodynamic parameters in nonlinear aircraft dynamic models during turbulence was developed and demonstrated. The approach uses an estimate of the measurement noise covariance to identify the model parameters, their uncertainties, and the process noise covariance, in a relaxation method analogous to the output-error method. Prior information on the model parameters and uncertainties can be supplied, and a post-estimation correction to the uncertainty was included to account for colored residuals not considered in the theory. No tuning parameters, needing adjustment by the analyst, are used in the estimation. The method was demonstrated in simulation using the NASA Generic Transport Model, then applied to the subscale T-2 jet-engine transport aircraft flight. Modeling results in different levels of turbulence were compared with results from time-domain output error and frequency- domain equation error methods to demonstrate the effectiveness of the approach.

Aircraft gas-turbine engines: Noise reduction and vibration control. (Latest citations from Information Services in Mechanical Engineering data base). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-06-01

The bibliography contains citations concerning the design and analysis of aircraft gas turbine engines with respect to noise and vibration control. Included are studies regarding the measurement and reduction of noise at its source, within the aircraft, and on the ground. Inlet, nozzle and core aerodynamic studies are cited. Propfan, turbofan, turboprop engines, and applications in short take-off and landing (STOL) aircraft are included. (Contains a minimum of 202 citations and includes a subject term index and title list.)

Aircraft Energy Efficiency (ACEE) status report

NASA Technical Reports Server (NTRS)

Nored, D. L.; Dugan, J. F., Jr.; Saunders, N. T.; Ziemianski, J. A.

1979-01-01

Fuel efficiency in aeronautics, for fuel conservation in general as well as for its effect on commercial aircraft operating economics is considered. Projects of the Aircraft Energy Efficiency Program related to propulsion are emphasized. These include: (1) engine component improvement, directed at performance improvement and engine diagnostics for prolonged service life; (2) energy efficient engine, directed at proving the technology base for the next generation of turbofan engines; and (3) advanced turboprop, directed at advancing the technology of turboprop powered aircraft to a point suitable for commercial airline service. Progress in these technology areas is reported.

The military operator's experience of reliability and maintainability characteristics

NASA Astrophysics Data System (ADS)

Jones, R. Mcc.

An account is given of the British Army's approach to the achievement of high reliability and maintainability in rotorcraft during the procurement process. Attention is given to experience accumulated to date with the Gazelle, Scout, Agusta A109A, and Lynx helicopters; these offer lessons with respect to the Gem engine, fuel filtering, vibration, and an aircraft flight control system.

System and Method for Providing a Real Time Audible Message to a Pilot

NASA Technical Reports Server (NTRS)

Johnson, Walter W. (Inventor); Lachter, Joel B. (Inventor); Koteskey, Robert W. (Inventor); Battiste, Vernol (Inventor)

2016-01-01

A system and method for providing information to a crew of the aircraft while in-flight. The system includes a module having: a receiver for receiving a message while in-flight; a filter having a set of screening parameters and operative to filter the message based on the set of screening parameters; and a converter for converting the message into an audible message. The message includes a pilot report having at least one of weather information, separation information, congestion information, flight deviation information and destination information. The message is sent to the aircraft by another aircraft or an air traffic controller.

Aircraft gas-turbine engines: noise reduction and vibration control. January 1973-November 1988 (Citations from Information Services in Mechanical Engineering data base). Report for January 1973-November 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1988-12-01

This bibliography contains citations concerning the design of aircraft gas-turbine engines with respect to noise reduction and vibration control. The aerodynamics of inlet design is presented for several types of engine applications including turbofan, turboprop, and vertical takeoff and landing aircraft. Helicopter engines are excluded from this bibliography. (This updated bibliography contains 212 citations, 28 of which are new entries to the previous edition.)

A Comprehensive Program for Measurement of Military Aircraft Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Mengdawn

2009-11-01

Emissions of gases and particulate matter by military aircraft were characterized inplume by 'extractive' and 'optical remote-sensing (ORS)' technologies. Non-volatile particle size distribution, number and mass concentrations were measured with good precision and reproducibly. Time-integrated particulate filter samples were collected and analyzed for smoke number, elemental composition, carbon contents, and sulfate. Observed at EEP the geometric mean diameter (as measured by the mobility diameter) generally increased as the engine power setting increased, which is consistent with downstream observations. The modal diameters at the downstream locations are larger than that at EEP at the same engine power level. The results indicatemore » that engine particles were processed by condensation, for example, leading to particle growth in-plume. Elemental analysis indicated little metals were present in the exhaust, while most of the exhaust materials in the particulate phase were carbon and sulfate (in the JP-8 fuel). CO, CO{sub 2}, NO, NO{sub 2}, SO{sub 2}, HCHO, ethylene, acetylene, propylene, and alkanes were measured. The last five species were most noticeable under engine idle condition. The levels of hydrocarbons emitted at high engine power level were generally below the detection limits. ORS techniques yielded real-time gaseous measurement, but the same techniques could not be extended directly to ultrafine particles found in all engine exhausts. The results validated sampling methodology and measurement techniques used for non-volatile particulate aircraft emissions, which also highlighted the needs for further research on sampling and measurement for volatile particulate matter and semi-volatile species in the engine exhaust especially at the low engine power setting.« less

Exergy as a useful tool for the performance assessment of aircraft gas turbine engines: A key review

NASA Astrophysics Data System (ADS)

Şöhret, Yasin; Ekici, Selcuk; Altuntaş, Önder; Hepbasli, Arif; Karakoç, T. Hikmet

2016-05-01

It is known that aircraft gas turbine engines operate according to thermodynamic principles. Exergy is considered a very useful tool for assessing machines working on the basis of thermodynamics. In the current study, exergy-based assessment methodologies are initially explained in detail. A literature overview is then presented. According to the literature overview, turbofans may be described as the most investigated type of aircraft gas turbine engines. The combustion chamber is found to be the most irreversible component, and the gas turbine component needs less exergetic improvement compared to all other components of an aircraft gas turbine engine. Finally, the need for analyses of exergy, exergo-economic, exergo-environmental and exergo-sustainability for aircraft gas turbine engines is emphasized. A lack of agreement on exergy analysis paradigms and assumptions is noted by the authors. Exergy analyses of aircraft gas turbine engines, fed with conventional fuel as well as alternative fuel using advanced exergy analysis methodology to understand the interaction among components, are suggested to those interested in thermal engineering, aerospace engineering and environmental sciences.

An in-flight investigation of pilot-induced oscillation suppression filters during the fighter approach and landing task

NASA Technical Reports Server (NTRS)

Bailey, R. E.; Smith, R. E.

1982-01-01

An investigation of pilot-induced oscillation suppression (PIOS) filters was performed using the USAF/Flight Dynamics Laboratory variable stability NT-33 aircraft, modified and operated by Calspan. This program examined the effects of PIOS filtering on the longitudinal flying qualities of fighter aircraft during the visual approach and landing task. Forty evaluations were flown to test the effects of different PIOS filters. Although detailed analyses were not undertaken, the results indicate that PIOS filtering can improve the flying qualities of an otherwise unacceptable aircraft configuration (Level 3 flying qualities). However, the ability of the filters to suppress pilot-induced oscillations appears to be dependent upon the aircraft configuration characteristics. Further, the data show that the filters can adversely affect landing flying qualities if improperly designed. The data provide an excellent foundation from which detail analyses can be performed.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure.

PubMed

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-05-11

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure

PubMed Central

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-01-01

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures. PMID:28772879

Cycle Counting Methods of the Aircraft Engine

ERIC Educational Resources Information Center

Fedorchenko, Dmitrii G.; Novikov, Dmitrii K.

2016-01-01

The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis…

Determination and Applications of Environmental Costs at Different Sized Airports: Aircraft Noise and Engine Emissions

NASA Technical Reports Server (NTRS)

Lu, Cherie; Lierens, Abigail

2003-01-01

With the increasing trend of charging for externalities and the aim of encouraging the sustainable development of the air transport industry, there is a need to evaluate the social costs of these undesirable side effects, mainly aircraft noise and engine emissions, for different airports. The aircraft noise and engine emissions social costs are calculated in monetary terms for five different airports, ranging from hub airports to small regional airports. The number of residences within different levels of airport noise contours and the aircraft noise classifications are the main determinants for accessing aircraft noise social costs. Whist, based on the damages of different engine pollutants on the human health, vegetation, materials, aquatic ecosystem and climate, the aircraft engine emissions social costs vary from engine types to aircraft categories. The results indicate that the relationship appears to be curvilinear between environmental costs and the traffic volume of an airport. The results and methodology of environmental cost calculation could input for to the proposed European wide harmonized noise charges as well as the social cost benefit analysis of airports.

Minimum time acceleration of aircraft turbofan engines by using an algorithm based on nonlinear programming

NASA Technical Reports Server (NTRS)

Teren, F.

1977-01-01

Minimum time accelerations of aircraft turbofan engines are presented. The calculation of these accelerations was made by using a piecewise linear engine model, and an algorithm based on nonlinear programming. Use of this model and algorithm allows such trajectories to be readily calculated on a digital computer with a minimal expenditure of computer time.

State variable modeling of the integrated engine and aircraft dynamics

NASA Astrophysics Data System (ADS)

Rotaru, Constantin; Sprinţu, Iuliana

2014-12-01

This study explores the dynamic characteristics of the combined aircraft-engine system, based on the general theory of the state variables for linear and nonlinear systems, with details leading first to the separate formulation of the longitudinal and the lateral directional state variable models, followed by the merging of the aircraft and engine models into a single state variable model. The linearized equations were expressed in a matrix form and the engine dynamics was included in terms of variation of thrust following a deflection of the throttle. The linear model of the shaft dynamics for a two-spool jet engine was derived by extending the one-spool model. The results include the discussion of the thrust effect upon the aircraft response when the thrust force associated with the engine has a sizable moment arm with respect to the aircraft center of gravity for creating a compensating moment.

Take-off engine particle emission indices for in-service aircraft at Los Angeles International Airport.

PubMed

Moore, Richard H; Shook, Michael A; Ziemba, Luke D; DiGangi, Joshua P; Winstead, Edward L; Rauch, Bastian; Jurkat, Tina; Thornhill, Kenneth L; Crosbie, Ewan C; Robinson, Claire; Shingler, Taylor J; Anderson, Bruce E

2017-12-19

We present ground-based, advected aircraft engine emissions from flights taking off at Los Angeles International Airport. 275 discrete engine take-off plumes were observed on 18 and 25 May 2014 at a distance of 400 m downwind of the runway. CO 2 measurements are used to convert the aerosol data into plume-average emissions indices that are suitable for modelling aircraft emissions. Total and non-volatile particle number EIs are of order 10 16 -10 17 kg -1 and 10 14 -10 16 kg -1 , respectively. Black-carbon-equivalent particle mass EIs vary between 175-941 mg kg -1 (except for the GE GEnx engines at 46 mg kg -1 ). Aircraft tail numbers recorded for each take-off event are used to incorporate aircraft- and engine-specific parameters into the data set. Data acquisition and processing follow standard methods for quality assurance. A unique aspect of the data set is the mapping of aerosol concentration time series to integrated plume EIs, aircraft and engine specifications, and manufacturer-reported engine emissions certifications. The integrated data enable future studies seeking to understand and model aircraft emissions and their impact on air quality.

Take-off engine particle emission indices for in-service aircraft at Los Angeles International Airport

PubMed Central

Moore, Richard H.; Shook, Michael A.; Ziemba, Luke D.; DiGangi, Joshua P.; Winstead, Edward L.; Rauch, Bastian; Jurkat, Tina; Thornhill, Kenneth L.; Crosbie, Ewan C.; Robinson, Claire; Shingler, Taylor J.; Anderson, Bruce E.

2017-01-01

We present ground-based, advected aircraft engine emissions from flights taking off at Los Angeles International Airport. 275 discrete engine take-off plumes were observed on 18 and 25 May 2014 at a distance of 400 m downwind of the runway. CO2 measurements are used to convert the aerosol data into plume-average emissions indices that are suitable for modelling aircraft emissions. Total and non-volatile particle number EIs are of order 1016–1017 kg−1 and 1014–1016 kg−1, respectively. Black-carbon-equivalent particle mass EIs vary between 175–941 mg kg−1 (except for the GE GEnx engines at 46 mg kg−1). Aircraft tail numbers recorded for each take-off event are used to incorporate aircraft- and engine-specific parameters into the data set. Data acquisition and processing follow standard methods for quality assurance. A unique aspect of the data set is the mapping of aerosol concentration time series to integrated plume EIs, aircraft and engine specifications, and manufacturer-reported engine emissions certifications. The integrated data enable future studies seeking to understand and model aircraft emissions and their impact on air quality. PMID:29257135

Take-off engine particle emission indices for in-service aircraft at Los Angeles International Airport

NASA Astrophysics Data System (ADS)

Moore, Richard H.; Shook, Michael A.; Ziemba, Luke D.; Digangi, Joshua P.; Winstead, Edward L.; Rauch, Bastian; Jurkat, Tina; Thornhill, Kenneth L.; Crosbie, Ewan C.; Robinson, Claire; Shingler, Taylor J.; Anderson, Bruce E.

2017-12-01

We present ground-based, advected aircraft engine emissions from flights taking off at Los Angeles International Airport. 275 discrete engine take-off plumes were observed on 18 and 25 May 2014 at a distance of 400 m downwind of the runway. CO2 measurements are used to convert the aerosol data into plume-average emissions indices that are suitable for modelling aircraft emissions. Total and non-volatile particle number EIs are of order 1016-1017 kg-1 and 1014-1016 kg-1, respectively. Black-carbon-equivalent particle mass EIs vary between 175-941 mg kg-1 (except for the GE GEnx engines at 46 mg kg-1). Aircraft tail numbers recorded for each take-off event are used to incorporate aircraft- and engine-specific parameters into the data set. Data acquisition and processing follow standard methods for quality assurance. A unique aspect of the data set is the mapping of aerosol concentration time series to integrated plume EIs, aircraft and engine specifications, and manufacturer-reported engine emissions certifications. The integrated data enable future studies seeking to understand and model aircraft emissions and their impact on air quality.

Effects of Ultra-Clean and centrifugal filtration on rolling-element bearing life

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.; Needelman, W. M.

1981-01-01

Fatigue tests were conducted on groups of 65-millimeter bore diameter deep-groove ball bearings in a MIL-L-23699 lubricant under two levels of filtration. In one test series, the oil cleanliness was maintained at an exceptionally high level (better than a class "000" per NAS 1638) with a 3 micron absolute barrier filter. These tests were intended to determine the "upper limit" in bearing life under the strictest possible lubricant cleanliness conditions. In the tests using a centrifugal oil filter, contaminants of the type found in aircraft engine filters were injected into the filters' supply line at 125 milligrams per bearing-hour. "Ultra-clean" lubrication produced bearing fatigue lives that were approximately twice that obtained in previous tests with contaminated oil using 3 micron absolute filtration and approximately three times that obtained with 49 micron filtration. It was also observed that the centrifugal oil filter had approximately the same effectiveness as a 30 micron absolute filter in preventing bearing surface damage.

Real-Time Aircraft Engine-Life Monitoring

NASA Technical Reports Server (NTRS)

Klein, Richard

2014-01-01

This project developed an inservice life-monitoring system capable of predicting the remaining component and system life of aircraft engines. The embedded system provides real-time, inflight monitoring of the engine's thrust, exhaust gas temperature, efficiency, and the speed and time of operation. Based upon this data, the life-estimation algorithm calculates the remaining life of the engine components and uses this data to predict the remaining life of the engine. The calculations are based on the statistical life distribution of the engine components and their relationship to load, speed, temperature, and time.

Emissions of NOx, particle mass and particle numbers from aircraft main engines, APU's and handling equipment at Copenhagen Airport

NASA Astrophysics Data System (ADS)

Winther, Morten; Kousgaard, Uffe; Ellermann, Thomas; Massling, Andreas; Nøjgaard, Jacob Klenø; Ketzel, Matthias

2015-01-01

This paper presents a detailed emission inventory for NOx, particle mass (PM) and particle numbers (PN) for aircraft main engines, APU's and handling equipment at Copenhagen Airport (CPH) based on time specific activity data and representative emission factors for the airport. The inventory has a high spatial resolution of 5 m × 5 m in order to be suited for further air quality dispersion calculations. Results are shown for the entire airport and for a section of the airport apron area ("inner apron") in focus. The methodology presented in this paper can be used to quantify the emissions from aircraft main engines, APU and handling equipment in other airports. For the entire airport, aircraft main engines is the largest source of fuel consumption (93%), NOx, (87%), PM (61%) and PN (95%). The calculated fuel consumption [NOx, PM, PN] shares for APU's and handling equipment are 5% [4%, 8%, 5%] and 2% [9%, 31%, 0%], respectively. At the inner apron area for handling equipment the share of fuel consumption [NOx, PM, PN] are 24% [63%, 75%, 2%], whereas APU and main engines shares are 43% [25%, 19%, 54%], and 33% [11%, 6%, 43%], respectively. The inner apron NOx and PM emission levels are high for handling equipment due to high emission factors for the diesel fuelled handling equipment and small for aircraft main engines due to small idle-power emission factors. Handling equipment is however a small PN source due to the low number based emission factors. Jet fuel sulphur-PM sensitivity calculations made in this study with the ICAO FOA3.0 method suggest that more than half of the PM emissions from aircraft main engines at CPH originate from the sulphur content of the fuel used at the airport. Aircraft main engine PN emissions are very sensitive to the underlying assumptions. Replacing this study's literature based average emission factors with "high" and "low" emission factors from the literature, the aircraft main engine PN emissions were estimated to change with a factor of 14.

Computation of maximum gust loads in nonlinear aircraft using a new method based on the matched filter approach and numerical optimization

NASA Technical Reports Server (NTRS)

Pototzky, Anthony S.; Heeg, Jennifer; Perry, Boyd, III

1990-01-01

Time-correlated gust loads are time histories of two or more load quantities due to the same disturbance time history. Time correlation provides knowledge of the value (magnitude and sign) of one load when another is maximum. At least two analysis methods have been identified that are capable of computing maximized time-correlated gust loads for linear aircraft. Both methods solve for the unit-energy gust profile (gust velocity as a function of time) that produces the maximum load at a given location on a linear airplane. Time-correlated gust loads are obtained by re-applying this gust profile to the airplane and computing multiple simultaneous load responses. Such time histories are physically realizable and may be applied to aircraft structures. Within the past several years there has been much interest in obtaining a practical analysis method which is capable of solving the analogous problem for nonlinear aircraft. Such an analysis method has been the focus of an international committee of gust loads specialists formed by the U.S. Federal Aviation Administration and was the topic of a panel discussion at the Gust and Buffet Loads session at the 1989 SDM Conference in Mobile, Alabama. The kinds of nonlinearities common on modern transport aircraft are indicated. The Statical Discrete Gust method is capable of being, but so far has not been, applied to nonlinear aircraft. To make the method practical for nonlinear applications, a search procedure is essential. Another method is based on Matched Filter Theory and, in its current form, is applicable to linear systems only. The purpose here is to present the status of an attempt to extend the matched filter approach to nonlinear systems. The extension uses Matched Filter Theory as a starting point and then employs a constrained optimization algorithm to attack the nonlinear problem.

DEKFIS user's guide: Discrete Extended Kalman Filter/Smoother program for aircraft and rotorcraft data consistency

NASA Technical Reports Server (NTRS)

1979-01-01

The computer program DEKFIS (discrete extended Kalman filter/smoother), formulated for aircraft and helicopter state estimation and data consistency, is described. DEKFIS is set up to pre-process raw test data by removing biases, correcting scale factor errors and providing consistency with the aircraft inertial kinematic equations. The program implements an extended Kalman filter/smoother using the Friedland-Duffy formulation.

Multispectral imaging of aircraft exhaust

NASA Astrophysics Data System (ADS)

Berkson, Emily E.; Messinger, David W.

2016-05-01

Aircraft pollutants emitted during the landing-takeoff (LTO) cycle have significant effects on the local air quality surrounding airports. There are currently no inexpensive, portable, and unobtrusive sensors to quantify the amount of pollutants emitted from aircraft engines throughout the LTO cycle or to monitor the spatial-temporal extent of the exhaust plume. We seek to thoroughly characterize the unburned hydrocarbon (UHC) emissions from jet engine plumes and to design a portable imaging system to remotely quantify the emitted UHCs and temporally track the distribution of the plume. This paper shows results from the radiometric modeling of a jet engine exhaust plume and describes a prototype long-wave infrared imaging system capable of meeting the above requirements. The plume was modeled with vegetation and sky backgrounds, and filters were selected to maximize the detectivity of the plume. Initial calculations yield a look-up chart, which relates the minimum amount of emitted UHCs required to detect the presence of a plume to the noise-equivalent radiance of a system. Future work will aim to deploy the prototype imaging system at the Greater Rochester International Airport to assess the applicability of the system on a national scale. This project will help monitor the local pollution surrounding airports and allow better-informed decision-making regarding emission caps and pollution bylaws.

Technologies for Aircraft Noise Reduction

NASA Technical Reports Server (NTRS)

Huff, Dennis L.

2006-01-01

Technologies for aircraft noise reduction have been developed by NASA over the past 15 years through the Advanced Subsonic Technology (AST) Noise Reduction Program and the Quiet Aircraft Technology (QAT) project. This presentation summarizes highlights from these programs and anticipated noise reduction benefits for communities surrounding airports. Historical progress in noise reduction and technologies available for future aircraft/engine development are identified. Technologies address aircraft/engine components including fans, exhaust nozzles, landing gear, and flap systems. New "chevron" nozzles have been developed and implemented on several aircraft in production today that provide significant jet noise reduction. New engines using Ultra-High Bypass (UHB) ratios are projected to provide about 10 EPNdB (Effective Perceived Noise Level in decibels) engine noise reduction relative to the average fleet that was flying in 1997. Audio files are embedded in the presentation that estimate the sound levels for a 35,000 pound thrust engine for takeoff and approach power conditions. The predictions are based on actual model scale data that was obtained by NASA. Finally, conceptual pictures are shown that look toward future aircraft/propulsion systems that might be used to obtain further noise reduction.

Filtration effects on ball bearing life and condition in a contaminated lubricant

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.

1978-01-01

Ball bearings were fatigue tested with a noncontaminated lubricant and with a contaminated lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3 and 30 micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49 micron bearings were statistically lower. The 105 micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers

PubMed Central

Chang, Xiaodong; Huang, Jinquan; Lu, Feng

2017-01-01

For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios. PMID:28398255

Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers.

PubMed

Chang, Xiaodong; Huang, Jinquan; Lu, Feng

2017-04-11

For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios.

A de-noising algorithm based on wavelet threshold-exponential adaptive window width-fitting for ground electrical source airborne transient electromagnetic signal

NASA Astrophysics Data System (ADS)

Ji, Yanju; Li, Dongsheng; Yu, Mingmei; Wang, Yuan; Wu, Qiong; Lin, Jun

2016-05-01

The ground electrical source airborne transient electromagnetic system (GREATEM) on an unmanned aircraft enjoys considerable prospecting depth, lateral resolution and detection efficiency, etc. In recent years it has become an important technical means of rapid resources exploration. However, GREATEM data are extremely vulnerable to stationary white noise and non-stationary electromagnetic noise (sferics noise, aircraft engine noise and other human electromagnetic noises). These noises will cause degradation of the imaging quality for data interpretation. Based on the characteristics of the GREATEM data and major noises, we propose a de-noising algorithm utilizing wavelet threshold method and exponential adaptive window width-fitting. Firstly, the white noise is filtered in the measured data using the wavelet threshold method. Then, the data are segmented using data window whose step length is even logarithmic intervals. The data polluted by electromagnetic noise are identified within each window based on the discriminating principle of energy detection, and the attenuation characteristics of the data slope are extracted. Eventually, an exponential fitting algorithm is adopted to fit the attenuation curve of each window, and the data polluted by non-stationary electromagnetic noise are replaced with their fitting results. Thus the non-stationary electromagnetic noise can be effectively removed. The proposed algorithm is verified by the synthetic and real GREATEM signals. The results show that in GREATEM signal, stationary white noise and non-stationary electromagnetic noise can be effectively filtered using the wavelet threshold-exponential adaptive window width-fitting algorithm, which enhances the imaging quality.

A hybrid PCA-CART-MARS-based prognostic approach of the remaining useful life for aircraft engines.

PubMed

Sánchez Lasheras, Fernando; García Nieto, Paulino José; de Cos Juez, Francisco Javier; Mayo Bayón, Ricardo; González Suárez, Victor Manuel

2015-03-23

Prognostics is an engineering discipline that predicts the future health of a system. In this research work, a data-driven approach for prognostics is proposed. Indeed, the present paper describes a data-driven hybrid model for the successful prediction of the remaining useful life of aircraft engines. The approach combines the multivariate adaptive regression splines (MARS) technique with the principal component analysis (PCA), dendrograms and classification and regression trees (CARTs). Elements extracted from sensor signals are used to train this hybrid model, representing different levels of health for aircraft engines. In this way, this hybrid algorithm is used to predict the trends of these elements. Based on this fitting, one can determine the future health state of a system and estimate its remaining useful life (RUL) with accuracy. To evaluate the proposed approach, a test was carried out using aircraft engine signals collected from physical sensors (temperature, pressure, speed, fuel flow, etc.). Simulation results show that the PCA-CART-MARS-based approach can forecast faults long before they occur and can predict the RUL. The proposed hybrid model presents as its main advantage the fact that it does not require information about the previous operation states of the input variables of the engine. The performance of this model was compared with those obtained by other benchmark models (multivariate linear regression and artificial neural networks) also applied in recent years for the modeling of remaining useful life. Therefore, the PCA-CART-MARS-based approach is very promising in the field of prognostics of the RUL for aircraft engines.

A Hybrid PCA-CART-MARS-Based Prognostic Approach of the Remaining Useful Life for Aircraft Engines

PubMed Central

Lasheras, Fernando Sánchez; Nieto, Paulino José García; de Cos Juez, Francisco Javier; Bayón, Ricardo Mayo; Suárez, Victor Manuel González

2015-01-01

Prognostics is an engineering discipline that predicts the future health of a system. In this research work, a data-driven approach for prognostics is proposed. Indeed, the present paper describes a data-driven hybrid model for the successful prediction of the remaining useful life of aircraft engines. The approach combines the multivariate adaptive regression splines (MARS) technique with the principal component analysis (PCA), dendrograms and classification and regression trees (CARTs). Elements extracted from sensor signals are used to train this hybrid model, representing different levels of health for aircraft engines. In this way, this hybrid algorithm is used to predict the trends of these elements. Based on this fitting, one can determine the future health state of a system and estimate its remaining useful life (RUL) with accuracy. To evaluate the proposed approach, a test was carried out using aircraft engine signals collected from physical sensors (temperature, pressure, speed, fuel flow, etc.). Simulation results show that the PCA-CART-MARS-based approach can forecast faults long before they occur and can predict the RUL. The proposed hybrid model presents as its main advantage the fact that it does not require information about the previous operation states of the input variables of the engine. The performance of this model was compared with those obtained by other benchmark models (multivariate linear regression and artificial neural networks) also applied in recent years for the modeling of remaining useful life. Therefore, the PCA-CART-MARS-based approach is very promising in the field of prognostics of the RUL for aircraft engines. PMID:25806876

Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts.

PubMed

Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

2017-02-18

Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor.

Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts

PubMed Central

Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

2017-01-01

Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor. PMID:28218700

Update of aircraft profile data for the Integrated Noise Model computer program, vol. 3 : appendix B aircraft performance coefficients

DOT National Transportation Integrated Search

1992-03-01

This report provides aircraft takeoff and landing profiles, : aircraft aerodynamic performance coefficients and engine : performance coefficients for the aircraft data base : (Database 9) in the Integrated Noise Model (INM) computer : program. Flight...

A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control

NASA Astrophysics Data System (ADS)

Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi; Yasui, Hisako

The Integrated Flight and Propulsion Control (IFPC) for a highly maneuverable aircraft and a fighter-class engine with pitch/yaw thrust vectoring is described. Of the two IFPC functions the aircraft maneuver control utilizes the thrust vectoring based on aerodynamic control surfaces/thrust vectoring control allocation specified by the Integrated Control Unit (ICU) of a FADEC (Full Authority Digital Electronic Control) system. On the other hand in the Performance Seeking Control (PSC) the ICU identifies engine's various characteristic changes, optimizes manipulated variables and finally adjusts engine control parameters in cooperation with the Engine Control Unit (ECU). It is shown by hardware-in-the-loop simulation that the thrust vectoring can enhance aircraft maneuverability/agility and that the PSC can improve engine performance parameters such as SFC (specific fuel consumption), thrust and gas temperature.

A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

NASA Technical Reports Server (NTRS)

Otugen, M. Volkan

1997-01-01

Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of a new laser-based strain-rate and vorticity technique for the time-resolved measurement of vorticity and strain-rates in turbulent flows.

State Estimation for Landing Maneuver on High Performance Aircraft

NASA Astrophysics Data System (ADS)

Suresh, P. S.; Sura, Niranjan K.; Shankar, K.

2018-01-01

State estimation methods are popular means for validating aerodynamic database on aircraft flight maneuver performance characteristics. In this work, the state estimation method during landing maneuver is explored for the first of its kind, using upper diagonal adaptive extended Kalman filter (UD-AEKF) with fuzzy based adaptive tunning of process noise matrix. The mathematical model for symmetrical landing maneuver consists of non-linear flight mechanics equation representing Aircraft longitudinal dynamics. The UD-AEKF algorithm is implemented in MATLAB environment and the states with bias is considered to be the initial conditions just prior to the flare. The measurement data is obtained from a non-linear 6 DOF pilot in loop simulation using FORTRAN. These simulated measurement data is additively mixed with process and measurement noises, which are used as an input for UD-AEKF. Then, the governing states that dictate the landing loads at the instant of touch down are compared. The method is verified using flight data wherein, the vertical acceleration at the aircraft center of gravity (CG) is compared. Two possible outcome of purely relying on the aircraft measured data is highlighted. It is observed that, with the implementation of adaptive fuzzy logic based extended Kalman filter tuned to adapt for aircraft landing dynamics, the methodology improves the data quality of the states that are sourced from noisy measurements.

Jet aircraft emissions during cruise: Present and future

NASA Technical Reports Server (NTRS)

Grobman, J. S.

1975-01-01

Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

A preliminary evaluation of a failure detection filter for detecting and identifying control element failures in a transport aircraft

NASA Technical Reports Server (NTRS)

Bundick, W. T.

1985-01-01

The application of the failure detection filter to the detection and identification of aircraft control element failures was evaluated in a linear digital simulation of the longitudinal dynamics of a B-737 Aircraft. Simulation results show that with a simple correlator and threshold detector used to process the filter residuals, the failure detection performance is seriously degraded by the effects of turbulence.

Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

NASA Technical Reports Server (NTRS)

Grobman, J.; Ingebo, R. D.

1974-01-01

Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

NASA Technical Reports Server (NTRS)

Grobman, J.; Ingebo, R. D.

1974-01-01

Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

Fault Diagnosis for the Heat Exchanger of the Aircraft Environmental Control System Based on the Strong Tracking Filter

PubMed Central

Ma, Jian; Lu, Chen; Liu, Hongmei

2015-01-01

The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system’s efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

PubMed

Ma, Jian; Lu, Chen; Liu, Hongmei

2015-01-01

The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

Update of aircraft profile data for the Integrated Noise Model computer program, vol. 2 : appendix A aircraft takeoff and landing profiles

DOT National Transportation Integrated Search

1992-03-01

This report provides aircraft takeoff and landing profiles, aircraft aerodynamic performance coefficients and engine performance coefficients for the aircraft data base (Database 9) in the Integrated Noise Model (INM) computer program. Flight profile...

The application of the detection filter to aircraft control surface and actuator failure detection and isolation

NASA Technical Reports Server (NTRS)

Bonnice, W. F.; Wagner, E.; Motyka, P.; Hall, S. R.

1985-01-01

The performance of the detection filter in detecting and isolating aircraft control surface and actuator failures is evaluated. The basic detection filter theory assumption of no direct input-output coupling is violated in this application due to the use of acceleration measurements for detecting and isolating failures. With this coupling, residuals produced by control surface failures may only be constrained to a known plane rather than to a single direction. A detection filter design with such planar failure signatures is presented, with the design issues briefly addressed. In addition, a modification to constrain the residual to a single known direction even with direct input-output coupling is also presented. Both the detection filter and the modification are tested using a nonlinear aircraft simulation. While no thresholds were selected, both filters demonstrated an ability to detect control surface and actuator failures. Failure isolation may be a problem if there are several control surfaces which produce similar effects on the aircraft. In addition, the detection filter was sensitive to wind turbulence and modeling errors.

Design and test of aircraft engine isolators for reduced interior noise

NASA Technical Reports Server (NTRS)

Unruh, J. F.; Scheidt, D. C.

1982-01-01

Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft. A study was carried out the objectives: (1) to develop an engine isolator design specification for reduced interior noise transmission, (2) select/design candidate isolators to meet a 15 dB noise reduction design goal, and (3) carry out a proof of concept evaluation test. Analytical model of the engine, vibration isolators and engine mount structure were coupled to an empirical model of the fuselage for noise transmission evaluation. The model was used to develop engine isolator dynamic properties design specification for reduced noise transmission. Candidate isolators ere chosen from available product literature and retrofit to a test aircraft. A laboratory based test procedure was then developed to simulate engine induced noise transmission in the aircraft for a proof of concept evaluation test. Three candidate isolator configurations were evaluated for reduced structure-borne noise transmission relative to the original equipment isolators.

Update of aircraft profile data for the Integrated Noise Model computer program, vol 1: final report

DOT National Transportation Integrated Search

1992-03-01

This report provides aircraft takeoff and landing profiles, aircraft aerodynamic performance coefficients and engine performance coefficients for the aircraft data base (Database 9) in the Integrated Noise Model (INM) computer program. Flight profile...

Analyses of integrated aircraft cabin contaminant monitoring network based on Kalman consensus filter.

PubMed

Wang, Rui; Li, Yanxiao; Sun, Hui; Chen, Zengqiang

2017-11-01

The modern civil aircrafts use air ventilation pressurized cabins subject to the limited space. In order to monitor multiple contaminants and overcome the hypersensitivity of the single sensor, the paper constructs an output correction integrated sensor configuration using sensors with different measurement theories after comparing to other two different configurations. This proposed configuration works as a node in the contaminant distributed wireless sensor monitoring network. The corresponding measurement error models of integrated sensors are also proposed by using the Kalman consensus filter to estimate states and conduct data fusion in order to regulate the single sensor measurement results. The paper develops the sufficient proof of the Kalman consensus filter stability when considering the system and the observation noises and compares the mean estimation and the mean consensus errors between Kalman consensus filter and local Kalman filter. The numerical example analyses show the effectiveness of the algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Filtration effects on ball bearing life and condition in a contaminated lubricant

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.

1978-01-01

Ball bearings were fatigue tested with a noncontaminated MIL-L-23699 lubricant and with a contaminated MIL-L-23699 lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3- and 30-micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49-micron bearings were statistically lower. The 105-micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

Integration of Engine, Plume, and CFD Analyses in Conceptual Design of Low-Boom Supersonic Aircraft

NASA Technical Reports Server (NTRS)

Li, Wu; Campbell, Richard; Geiselhart, Karl; Shields, Elwood; Nayani, Sudheer; Shenoy, Rajiv

2009-01-01

This paper documents an integration of engine, plume, and computational fluid dynamics (CFD) analyses in the conceptual design of low-boom supersonic aircraft, using a variable fidelity approach. In particular, the Numerical Propulsion Simulation System (NPSS) is used for propulsion system cycle analysis and nacelle outer mold line definition, and a low-fidelity plume model is developed for plume shape prediction based on NPSS engine data and nacelle geometry. This model provides a capability for the conceptual design of low-boom supersonic aircraft that accounts for plume effects. Then a newly developed process for automated CFD analysis is presented for CFD-based plume and boom analyses of the conceptual geometry. Five test cases are used to demonstrate the integrated engine, plume, and CFD analysis process based on a variable fidelity approach, as well as the feasibility of the automated CFD plume and boom analysis capability.

Full scale technology demonstration of a modern counterrotating unducted fan engine concept: Component test

NASA Technical Reports Server (NTRS)

1987-01-01

The UDF trademark (Unducted Fan) engine is a new aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio powerplant with exceptional fuel efficiency for subsonic aircraft application. This report covers the testing of pertinent components of this engine such as the fan blades, control and actuation system, turbine blades and spools, seals, and mixer frame.

An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

NASA Technical Reports Server (NTRS)

Rinehart, Aidan W.; Simon, Donald L.

2015-01-01

This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

NASA Technical Reports Server (NTRS)

Rinehart, Aidan W.; Simon, Donald L.

2014-01-01

This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

A STUDY OF EXTRACTIVE AND REMOTE-SENSING SAMPLING AND MEASUREMENT OF EMISSIONS FROM MILITARY AIRCRAFT ENGINES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Mengdawn; Corporan, E.

2010-01-01

Aircraft emissions contribute to the increased atmospheric burden of particulate matter (e.g., black carbon and secondary organic compounds) that plays a role in air quality, contrail formation and climate change. Sampling and measurement of modern aircraft emissions at the engine exhaust plane (EEP) for to engine and fuel certification remains a daunting task, no agency-certified method is available for the task. In this paper we summarize the results of a recent study that was devoted to investigate both extractive and optical remote-sensing (ORS) technologies in sampling and measurement of gaseous and particulate matter (PM) emitted by a number of militarymore » aircraft engines operated with JP-8 and a Fischer-Tropsch (FT) fuel at various engine conditions. These engines include cargo, bomber, and helicopter types of military aircraft that consumes 70-80% of the military aviation fuel each year. The emission indices of selected pollutants are discussed as these data may be of interest for atmospheric modeling and for design of air quality control strategies around the airports and military bases. It was found that non-volatile particles in the engine emissions were all in the ultrafine range. The mean diameter of particles increased as the engine power increased; the mode diameters were in the 20nm range for the low power condition of a new helicopter engine to 80nm for the high power condition of a newly maintained bomber engine. Elemental analysis indicated little metals were present on particles in the exhaust, while most of the materials on the exhaust particles were based on carbon and sulfate. Carbon monoxide, carbon dioxide, nitrogen oxide, sulfur dioxide, formaldehyde, ethylene, acetylene, propylene, and alkanes were detected using both technologies. The last five species (in the air toxics category) were most noticeable only under the low engine power. The emission indices calculated based on the ORS data were however observed to differ significantly (up to 90%) from (typically lower than) those based on the extractive techniques. However, the ORS techniques were useful in providing non-intrusive real-time measurements of gaseous species in the exhaust plume, which warrants further development. The results obtained in this program validate sampling methodology and measurement techniques used for non-volatile PM aircraft emissions as described in the SAE AIR-6037.« less

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2011 CFR

2011-04-01

... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines, ground...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2010 CFR

2010-04-01

... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines, ground...

Composite correlation filter for O-ring detection in stationary colored noise

NASA Astrophysics Data System (ADS)

Hassebrook, Laurence G.

2009-04-01

O-rings are regularly replaced in aircraft and if they are not replaced or if they are installed improperly, they can result in catastrophic failure of the aircraft. It is critical that the o-rings be packaged correctly to avoid mistakes made by technicians during routine maintenance. For this reason, fines may be imposed on the o-ring manufacturer if the o-rings are packaged incorrectly. That is, a single o-ring must be packaged and labeled properly. No o-rings or more than one o-ring per package is not acceptable. We present an industrial inspection system based on real-time composite correlation filtering that has successfully solved this problem in spite of opaque paper o-ring packages. We present the system design including the composite filter design.

Metal- matrix composite processing technologies for aircraft engine applications

NASA Astrophysics Data System (ADS)

Pank, D. R.; Jackson, J. J.

1993-06-01

Titanium metal-matrix composites (MMC) are prime candidate materials for aerospace applications be-cause of their excellent high-temperature longitudinal strength and stiffness and low density compared with nickel- and steel-base materials. This article examines the steps GE Aircraft Engines (GEAE) has taken to develop an induction plasma deposition (IPD) processing method for the fabrication of Ti6242/SiC MMC material. Information regarding process methodology, microstructures, and mechani-cal properties of consolidated MMC structures will be presented. The work presented was funded under the GE-Aircraft Engine IR & D program.

Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

NASA Technical Reports Server (NTRS)

Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl (Compiler); Guo, Ten-Huei

2014-01-01

The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

NASA Technical Reports Server (NTRS)

Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl; Guo, Ten-Huei

2015-01-01

The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

Adaptive Optimization of Aircraft Engine Performance Using Neural Networks

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Long, Theresa W.

1995-01-01

Preliminary results are presented on the development of an adaptive neural network based control algorithm to enhance aircraft engine performance. This work builds upon a previous National Aeronautics and Space Administration (NASA) effort known as Performance Seeking Control (PSC). PSC is an adaptive control algorithm which contains a model of the aircraft's propulsion system which is updated on-line to match the operation of the aircraft's actual propulsion system. Information from the on-line model is used to adapt the control system during flight to allow optimal operation of the aircraft's propulsion system (inlet, engine, and nozzle) to improve aircraft engine performance without compromising reliability or operability. Performance Seeking Control has been shown to yield reductions in fuel flow, increases in thrust, and reductions in engine fan turbine inlet temperature. The neural network based adaptive control, like PSC, will contain a model of the propulsion system which will be used to calculate optimal control commands on-line. Hopes are that it will be able to provide some additional benefits above and beyond those of PSC. The PSC algorithm is computationally intensive, it is valid only at near steady-state flight conditions, and it has no way to adapt or learn on-line. These issues are being addressed in the development of the optimal neural controller. Specialized neural network processing hardware is being developed to run the software, the algorithm will be valid at steady-state and transient conditions, and will take advantage of the on-line learning capability of neural networks. Future plans include testing the neural network software and hardware prototype against an aircraft engine simulation. In this paper, the proposed neural network software and hardware is described and preliminary neural network training results are presented.

Model-Based Engine Control Architecture with an Extended Kalman Filter

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Connolly, Joseph W.

2016-01-01

This paper discusses the design and implementation of an extended Kalman filter (EKF) for model-based engine control (MBEC). Previously proposed MBEC architectures feature an optimal tuner Kalman Filter (OTKF) to produce estimates of both unmeasured engine parameters and estimates for the health of the engine. The success of this approach relies on the accuracy of the linear model and the ability of the optimal tuner to update its tuner estimates based on only a few sensors. Advances in computer processing are making it possible to replace the piece-wise linear model, developed off-line, with an on-board nonlinear model running in real-time. This will reduce the estimation errors associated with the linearization process, and is typically referred to as an extended Kalman filter. The non-linear extended Kalman filter approach is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (C-MAPSS40k) and compared to the previously proposed MBEC architecture. The results show that the EKF reduces the estimation error, especially during transient operation.

Model-Based Engine Control Architecture with an Extended Kalman Filter

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Connolly, Joseph W.

2016-01-01

This paper discusses the design and implementation of an extended Kalman filter (EKF) for model-based engine control (MBEC). Previously proposed MBEC architectures feature an optimal tuner Kalman Filter (OTKF) to produce estimates of both unmeasured engine parameters and estimates for the health of the engine. The success of this approach relies on the accuracy of the linear model and the ability of the optimal tuner to update its tuner estimates based on only a few sensors. Advances in computer processing are making it possible to replace the piece-wise linear model, developed off-line, with an on-board nonlinear model running in real-time. This will reduce the estimation errors associated with the linearization process, and is typically referred to as an extended Kalman filter. The nonlinear extended Kalman filter approach is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (C-MAPSS40k) and compared to the previously proposed MBEC architecture. The results show that the EKF reduces the estimation error, especially during transient operation.

Flight test experience with pilot-induced-oscillation suppressor filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1983-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Flight test experience with pilot-induced-oscillation suppression filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1984-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

A 150 and 300 kW lightweight diesel aircraft engine design study

NASA Technical Reports Server (NTRS)

Brouwers, A. P.

1980-01-01

The diesel engine was reinvestigated as an aircraft powerplant through design study conducted to arrive at engine configurations and applicable advanced technologies. Two engines are discussed, a 300 kW six-cylinder engine for twin engine general aviation aircraft and a 150 kW four-cylinder engine for single engine aircraft. Descriptions of each engine include concept drawings, a performance analysis, stress and weight data, and a cost study. This information was used to develop two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consists of installation drawings, computer generated performance data, aircraft operating costs, and drawings of the resulting airplanes. The performance data show a vast improvement over current gasoline-powered aircraft.

A study of extractive and remote-sensing sampling and measurement of emissions from military aircraft engines

NASA Astrophysics Data System (ADS)

Cheng, Meng-Dawn; Corporan, Edwin

2010-12-01

Aircraft emissions contribute to the increased atmospheric burden of particulate matter (PM) that plays an important role in air quality, human health, visibility, contrail formation and climate change. Sampling and measurement of modern aircraft emissions at the engine exhaust plane (EEP) for engine and fuel certification remains challenging, as no agency-certified method is available. In this paper we summarize the results of three recent field studies devoted to investigate the consistency and applicability of "extractive" and "optical remote-sensing" (ORS) technologies in the sampling and measurement of gaseous and PM emitted by a number of military aircraft engines. Three classes of military engines were investigated; these include T56, TF33, and T700 & T701C types of engines, which consume 70-80% of the military aviation fuel each year. JP-8 and Fischer-Tropsch (FT)-derived paraffinic fuels were used to study the effect of fuels. It was found that non-volatile particles in the engine emissions were in the 20 nm range for the low power condition of new helicopter engines to 80 nm for the high power condition of legacy engines. Elemental analysis indicated little metals were present on particles, while most of the materials on the exhaust particles were carbon and sulfate based. Alkanes, carbon monoxide, carbon dioxide, nitrogen oxides, sulfur dioxide, formaldehyde, ethylene, acetylene and propylene were detected. The last five species were most noticeable only under low engine power. The emission indices calculated based on the ORS data deviate significantly from those based on the extractive data. Nevertheless, the ORS techniques were useful in the sense that it provided non-intrusive real-time detection of species in the exhaust plume, which warrants further development. The results obtained in this program help validate sampling methodology and measurement techniques used for non-volatile PM aircraft emissions as described in the SAE AIR6037 (2009).

Impact imaging of aircraft composite structure based on a model-independent spatial-wavenumber filter.

PubMed

Qiu, Lei; Liu, Bin; Yuan, Shenfang; Su, Zhongqing

2016-01-01

The spatial-wavenumber filtering technique is an effective approach to distinguish the propagating direction and wave mode of Lamb wave in spatial-wavenumber domain. Therefore, it has been gradually studied for damage evaluation in recent years. But for on-line impact monitoring in practical application, the main problem is how to realize the spatial-wavenumber filtering of impact signal when the wavenumber of high spatial resolution cannot be measured or the accurate wavenumber curve cannot be modeled. In this paper, a new model-independent spatial-wavenumber filter based impact imaging method is proposed. In this method, a 2D cross-shaped array constructed by two linear piezoelectric (PZT) sensor arrays is used to acquire impact signal on-line. The continuous complex Shannon wavelet transform is adopted to extract the frequency narrowband signals from the frequency wideband impact response signals of the PZT sensors. A model-independent spatial-wavenumber filter is designed based on the spatial-wavenumber filtering technique. Based on the designed filter, a wavenumber searching and best match mechanism is proposed to implement the spatial-wavenumber filtering of the frequency narrowband signals without modeling, which can be used to obtain a wavenumber-time image of the impact relative to a linear PZT sensor array. By using the two wavenumber-time images of the 2D cross-shaped array, the impact direction can be estimated without blind angle. The impact distance relative to the 2D cross-shaped array can be calculated by using the difference of time-of-flight between the frequency narrowband signals of two different central frequencies and the corresponding group velocities. The validations performed on a carbon fiber composite laminate plate and an aircraft composite oil tank show a good impact localization accuracy of the model-independent spatial-wavenumber filter based impact imaging method. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessing the shielding of engine noise by the wings for current aircraft using model predictions and measurements.

PubMed

Vieira, Ana; Snellen, Mirjam; Simons, Dick G

2018-01-01

Reducing aircraft noise is a major issue to be dealt with by the aerospace industry. In addition to lowering noise emissions from the engine and airframe, also the shielding of engine noise by the aircraft is considered as a promising means for reducing the perceived noise on the ground. In literature, noise shielding predictions indicate significant reductions in received noise levels for blended wing body configurations, but also for conventional aircraft with the engines placed above the wings. Little work has been done in assessing these potential shielding effects for full aircraft under real operational conditions. Therefore, in this work, noise shielding for current aircraft is investigated using both measurements and model predictions. The predictions are based on the Kirchhoff integral theory and the Modified Theory of Physical Optics. For the comparison between the predictions and measurements, Twenty Fokker 70 flyovers are considered. The data analysis approach for the extraction of shielding levels for aircraft under these operational conditions is presented. Directly under the flight path, the simulations predict an engine noise shielding of 6 dB overall sound pressure level. This is confirmed by some of the flyover data. On average, the measurements show somewhat lower shielding levels.

Computer code for estimating installed performance of aircraft gas turbine engines. Volume 3: Library of maps

NASA Technical Reports Server (NTRS)

Kowalski, E. J.

1979-01-01

A computerized method which utilizes the engine performance data and estimates the installed performance of aircraft gas turbine engines is presented. This installation includes: engine weight and dimensions, inlet and nozzle internal performance and drag, inlet and nacelle weight, and nacelle drag. The use of two data base files to represent the engine and the inlet/nozzle/aftbody performance characteristics is discussed. The existing library of performance characteristics for inlets and nozzle/aftbodies and an example of the 1000 series of engine data tables is presented.

System level airworthiness tool: A comprehensive approach to small unmanned aircraft system airworthiness

NASA Astrophysics Data System (ADS)

Burke, David A.

One of the pillars of aviation safety is assuring sound engineering practices through airworthiness certification. As Unmanned Aircraft Systems (UAS) grow in popularity, the need for airworthiness standards and verification methods tailored for UAS becomes critical. While airworthiness practices for large UAS may be similar to manned aircraft, it is clear that small UAS require a paradigm shift from the airworthiness practices of manned aircraft. Although small in comparison to manned aircraft these aircraft are not merely remote controlled toys. Small UAS may be complex aircraft flying in the National Airspace System (NAS) over populated areas for extended durations and beyond line of sight of the operators. A comprehensive systems engineering framework for certifying small UAS at the system level is needed. This work presents a point based tool that evaluates small UAS by rewarding good engineering practices in design, analysis, and testing. The airworthiness requirements scale with vehicle size and operational area, while allowing flexibility for new technologies and unique configurations.

Design study: A 186 kW lightweight diesel aircraft engine

NASA Technical Reports Server (NTRS)

Brouwers, A. P.

1980-01-01

The design of an aircraft engine capable of developing 186 kW shaft power at a 7620 m altitude is described. The 186 kW design takes into account expected new developments in aircraft designs resulting in a reassessment of the power requirements at the cruise mode operation. Based on the results of this analysis a three phase technology development program is projected resulting in production dates of 1985, 1992, and 2000.

High-temperature microelectromechanical pressure sensors based on a SOI heterostructure for an electronic automatic aircraft engine control system

NASA Astrophysics Data System (ADS)

Sokolov, Leonid V.

2010-08-01

There is a need of measuring distributed pressure on the aircraft engine inlet with high precision within a wide operating temperature range in the severe environment to improve the efficiency of aircraft engine control. The basic solutions and principles of designing high-temperature (to 523K) microelectromechanical pressure sensors based on a membrane-type SOI heterostructure with a monolithic integral tensoframe (MEMS-SOIMT) are proposed in accordance with the developed concept, which excludes the use of electric p-n junctions in semiconductor microelectromechanical sensors. The MEMS-SOIMT technology relies on the group processes of microelectronics and micromechanics for high-precision microprofiling of a three-dimension micromechanical structure, which exclude high-temperature silicon doping processes.

Self-pressurizing Stirling engine

DOEpatents

Bennett, Charles L.

2010-10-12

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Electrically heated particulate filter regeneration methods and systems for hybrid vehicles

DOEpatents

Gonze, Eugene V.; Paratore, Jr., Michael J.

2010-10-12

A control system for controlling regeneration of a particulate filter for a hybrid vehicle is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate regeneration. An engine control module controls operation of an engine of the hybrid vehicle based on the control of the current to the particulate filter.

Solar thermal aircraft

DOEpatents

Bennett, Charles L.

2007-09-18

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Partial study of quadrotor based on quaternions

NASA Astrophysics Data System (ADS)

Ji, Xiang

2018-05-01

In this paper, the attitude calculation of quadrotor is studied, and the attitude angle of quaternions and the method of using IIR low pass filter to filter the high frequency noise are proposed. First of all, this paper puts forward the characteristics of quadrotor more flexible than other aircraft. The flexible steering mode of quadrotor is classified into three categories. Starting from reality, this paper proposes an algorithm to transform the value of acceleration sensor to pose angle, which can greatly reduce the amount of computation and is the theoretical basis for real-time attitude calculation of aircraft. When introducing the number of quaternion, this article starts from the theoretical model and first introduces the conceptual meaning of the number of quaternion. In this model, the aircraft's own coordinate axis and the geographical axis are regarded as two rigid bodies, and they have three coordinate axes that are orthogonal to each other. When the steering operation is involved, the corresponding acceleration is generated. By using the quaternion multiplicative formula mentioned in this paper, the change of attitude angle can be obtained. n reality, in order to ensure the accuracy of the output attitude angle. More accurate input variables are often needed, and the IIR low pass filter is introduced in this way. In this paper, a nine order IIR filter is designed according to the actual situation, and its spectrum characteristics are obtained by simulation software. After mixing the original signal generated by propeller's high frequency noise, it outputs clean signals through filter, all of which are intuitively reflected by three spectrum images. After giving some practical solutions, this paper looks forward to the prospect of the aircraft.

Effect of filtration on rolling-element-bearing life in contaminated lubricant environment

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.; Sherlock, J. J.

1978-01-01

Fatigue tests were conducted on groups of 65 millimeter-bore ball bearings under four levels of filtration with and without a contaminated MIL-L-23699 lubricant. The baseline series used noncontaminated oil with 49 micron absolute filtration. In the remaining tests contaminants of the composition found in aircraft engine filters were injected into the filter's supply line at a constant rate of 125 milligrams per bearing-hour. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns (0.45, 10, 30, and 70 microns nominal), respectively. Bearings were tested at 15,000 rpm under 4580 newtons radial load. Bearing life and running tract condition generally improved with finer filtration. The 3 and 30 micron filter bearings in a contaminated lubricant had statistically equivalent lives, approaching those from the baseline tests. The experimental lives of 49 micron bearings were approximately half the baseline bearing's lives. Bearings tested with the 105 micron filter experienced wear failures. The degree of surface distress, weight loss, and probable failure mode were found to be dependent on filtration level, with finer filtration being clearly beneficial.

Aircraft dual-shaft jet engine with indirect action fuel flow controller

NASA Astrophysics Data System (ADS)

Tudosie, Alexandru-Nicolae

2017-06-01

The paper deals with an aircraft single-jet engine's control system, based on a fuel flow controller. Considering the engine as controlled object and its thrust the most important operation effect, from the multitude of engine's parameters only its rotational speed n is measurable and proportional to its thrust, so engine's speed has become the most important controlled parameter. Engine's control system is based on fuel injection Qi dosage, while the output is engine's speed n. Based on embedded system's main parts' mathematical models, the author has described the system by its block diagram with transfer functions; furthermore, some Simulink-Matlab simulations are performed, concerning embedded system quality (its output parameters time behavior) and, meanwhile, some conclusions concerning engine's parameters mutual influences are revealed. Quantitative determinations are based on author's previous research results and contributions, as well as on existing models (taken from technical literature). The method can be extended for any multi-spool engine, single- or twin-jet.

40 CFR 87.5 - Special test procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.5 Special test... aircraft or aircraft engines, approve test procedures for any aircraft or aircraft engine that is not...

77 FR 76842 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... , compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with...)(v). 6. Standards for Supersonic Aircraft Turbine Engines This final rule contains carbon monoxide...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2014 CFR

2014-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2013 CFR

2013-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2012 CFR

2012-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2013 CFR

2013-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2011 CFR

2011-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2014 CFR

2014-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

An Assessment of the Use of Antimisting Fuel in Turbofan Engines.

DTIC Science & Technology

1981-06-01

Angle PLA Shutoff Lever Angle SOLA Control Speed Nc Compressor Discharge Pressure Ps4 or Pb Compr’ssor Inlet Temperature Tt2 Metered Fuel Flow Wf Control...this comparison the Royal Aircraft Establishment deqrader had a lower filter ratio reduction, consumed more power, and had a higher tempera- ture rise...negligible. This would imply that little of the total enerqy consume 1 by the pump goes towa~rds d(,qrading the antimisting kerosene. Further dita analysis

Monitoring of pollutant gases in aircraft exhausts by gas-filter correlation methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gryvnak, D.A.; Burch, D.E.

1976-01-01

An infrared instrument using a gas-filter correlation technique was used to monitor NO and CO by looking across the exhaust plume of a T56 jet engine combustor. The instrument, built previously by Aeronutronic Ford for EPA to monitor pollutant gases in smokestack exhausts, was modified for use on the combustor. Temperatures and concentrations ranged from 300 to 930 K and up to 130 ppM for NO, and from 300 to 550/sup 0/K and up to 220 ppM for CO. The infrared results compared reasonably well with results that were obtained simultaneously by withdrawing the sample using probe techniques and analyzingmore » the gas with a conventional gas analyzer.« less

Voltage Stress on Y Capacitors from Indirect Lightning Pulses According to ED-14/DO-160

NASA Astrophysics Data System (ADS)

Meier, F.

2012-05-01

Transients due to lightning strikes on an aircraft's fuselage impose stress on the input filters of elec- tronic equipment. Permanent damage can occur when exceeding the voltage handling capacity of filter components causing a short circuit to ground. In ED-14/DO-160, section 22, a number of waveforms and levels are defined which are used to check the airworthiness of avionics equipment. Depending on pro- cedure and level, Y-capacitors are stressed by transient voltages which exceed their dielectric strength. The design engineer's task is a properly select the type and voltage rating of capacitors. With moderate simplifications, a LCR-series network is justified to calculate the peak voltage dependent on the capacitance.

Development of Iron Aluminides

DTIC Science & Technology

1987-05-01

in aircraft turbine engines as altIErnatives to high chromium steels and nickel-base alloys. The pirogram was divided into three tasks. A process and...RSR) and the determination of their potential for use in aircraft turbine engines as alternative. to high chromium steels and nickel-base alloys. The...intermediated temperatures. Any alloys must also exhibit adequate corrosion resistance in a gas turbine environment if they are to replace existing alloys. A

78 FR 70216 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation... all Thielert Aircraft Engines GmbH TAE 125-01 reciprocating engines. This AD requires applying sealant... directive (AD): 2013-24-06 Thielert Aircraft Engines GmbH: Amendment 39-17680; Docket No. FAA-2013-0561...

The development of turbojet aircraft in Germany, Britain, and the United States: A multi-national comparison of aeronautical engineering, 1935--1946

NASA Astrophysics Data System (ADS)

Pavelec, Sterling Michael

In the 1930s aeronautical engineering needed revision. A presumptive anomaly was envisaged as piston-engine aircraft flew higher and faster. Radical alternatives to piston engines were considered in the unending quest for speed. Concurrently, but unwittingly, two turbojet engine programs were undertaken in Europe. The air-breathing three-stage turbojet engine was based on previous turbine technology; the revolutionary idea was the gas turbine as a prime mover for aircraft. In Germany, Dr. Hans von Ohain was the first to complete a flight-worthy turbojet engine for aircraft. Installed in a Heinkel designed aircraft, the Germans began the jet age on 27 August 1939. The Germans led throughout the war and were the first to produce jet aircraft for combat operations. The principal limiting factor for the German jet program was a lack of reliable engines. The continuing myths that Hitler orders, too little fuel, or too few pilots hindered the program are false. In England, Frank Whittle, without substantial support, but with dogged determination, also developed a turbojet engine. The British came second in the jet race when the Whittle engine powered the Gloster Pioneer on 15 May 1941. The Whittle-Gloster relationship continued and produced the only Allied combat jet aircraft during the war, the Meteor, which was confined to Home Defense in Britain. The American turbojet program was built directly from the Whittle engine. General Electric copied the Whittle designs and Bell Aircraft was contracted to build the first American jet plane. The Americans began the jet age on 1 October 1942 with a lackluster performance from their first jet, the Airacomet. But the Americans forged ahead, and had numerous engine and airframe programs in development by the end of the war. But, the Germans did it right and did it first. Partly because of a predisposition towards excellent engineering and physics, partly out of necessity, the Germans were able to produce combat turbojet aircraft during the war. The Allies lagged from a lack of necessity, operational incompatibility, and stringent acceptance requirements. By the end of the war the Germans needed qualitative technological superiority to combat an overwhelming Allied quantitative advantage.

Field Evaluation of Six Protective Coatings Applied to T56 Turbines after 1500 Hours Engine Use

DTIC Science & Technology

1991-06-01

Six Coating Systems On First-stage Gas Turbine Blades In The Engines of a Long-Range Maritime Patrol Aircraft ", Surface and Coating Technology, 36...based coatings. They were applied to the first-stage turbine blades in the engines of two long range maritime patrol aircraft operated by the Royal...incorrect. These differently coated turbine - blades have in fact seen 1500 hours service in a T56 engine . The title and further reference in the text should

Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight.

PubMed

Durantin, Gautier; Scannella, Sébastien; Gateau, Thibault; Delorme, Arnaud; Dehais, Frédéric

2015-01-01

Working memory (WM) is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor WM as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering, and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces (BCI). We used functional near infrared spectroscopy as it has been already successfully tested to measure WM capacity in complex environment with air traffic controllers (ATC), pilots, or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with nine participants involving a basic WM task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with ATC instructions (two levels of difficulty). The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence (MACD) filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in WM. In addition, the use of a Kalman filter increased the performance of the classification of WM levels based on brain signal. The results suggest that Kalman filter is a suitable approach for real-time improvement of near infrared spectroscopy signal in ecological situations and the development of BCI.

Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight

PubMed Central

Durantin, Gautier; Scannella, Sébastien; Gateau, Thibault; Delorme, Arnaud; Dehais, Frédéric

2016-01-01

Working memory (WM) is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor WM as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering, and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces (BCI). We used functional near infrared spectroscopy as it has been already successfully tested to measure WM capacity in complex environment with air traffic controllers (ATC), pilots, or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with nine participants involving a basic WM task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with ATC instructions (two levels of difficulty). The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence (MACD) filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in WM. In addition, the use of a Kalman filter increased the performance of the classification of WM levels based on brain signal. The results suggest that Kalman filter is a suitable approach for real-time improvement of near infrared spectroscopy signal in ecological situations and the development of BCI. PMID:26834607

Optimal Lateral Guidance for Automatic Landing of a Lightweight High Altitude Long Endurance Unmanned Aerial System with Crosswind Rejection

NASA Astrophysics Data System (ADS)

Smith, Nathan Allen

Unmanned aerial systems will be the dominant force in the aviation industry. Among these aircraft the use of high altitude long endurance unmanned aerial systems has increased dramatically. Based on the geometry of these types of aircraft the possible changing weather conditions during long flights poses many problems. These difficulties are compounded by the push towards fully autonomous systems. Large wingspan and, typically, small in-line landing gear make a landing in crosswind exceedingly difficult. This study uses a modified gain scheduling technique for optimizing the landing attitude for a generic vehicle based on geometry and crosswind speed. This is performed by directly utilizing the crosswind estimation to calculate a desired crab and roll angle that gives the lowest risk attitude for landing. An extended Kalman filter is developed that estimates the aircraft states as well as the 3D wind component acting on the aircraft. The aircraft used in this analysis is the DG808S, a large wingspan lightweight electric glider. The aircraft is modelled using Advanced Aircraft Analysis software and a six degree of freedom nonlinear simulation is implemented for testing. The controller used is a nonlinear model predictive controller. The simulations show that the extended Kalman filter is capable of estimating the crosswind and can therefore be used in the full aircraft simulation. Different crosswind settings are used which include both constant crosswind and gust conditions. Crosswind landing capabilities are increased by 35%. Deviation from the desired path in the cruise phase is reduced by up to 68% and time to path convergence is reduced by up to 53%.

76 FR 40219 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

... Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY... installed on a limited number of engines. No defective washers have been shipped as spare parts. This... consequent ignition failure, possibly resulting in damage to the engine, in- flight engine shutdown and...

40 CFR 87.71 - Compliance with gaseous emission standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.71 Compliance with gaseous emission standards. Compliance with each gaseous emission standard by an aircraft engine shall be...

40 CFR 87.71 - Compliance with gaseous emission standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.71 Compliance with gaseous emission standards. Compliance with each gaseous emission standard by an aircraft engine shall be...

Compatibility check of measured aircraft responses using kinematic equations and extended Kalman filter

NASA Technical Reports Server (NTRS)

Klein, V.; Schiess, J. R.

1977-01-01

An extended Kalman filter smoother and a fixed point smoother were used for estimation of the state variables in the six degree of freedom kinematic equations relating measured aircraft responses and for estimation of unknown constant bias and scale factor errors in measured data. The computing algorithm includes an analysis of residuals which can improve the filter performance and provide estimates of measurement noise characteristics for some aircraft output variables. The technique developed was demonstrated using simulated and real flight test data. Improved accuracy of measured data was obtained when the data were corrected for estimated bias errors.

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

Rankline-Brayton engine powered solar thermal aircraft

DOEpatents

Bennett, Charles L [Livermore, CA

2012-03-13

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Rankine-Brayton engine powered solar thermal aircraft

DOEpatents

Bennett, Charles L [Livermore, CA

2009-12-29

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Emergency flight control system using one engine and fuel transfer

NASA Technical Reports Server (NTRS)

Burcham, Jr., Frank W. (Inventor); Burken, John J. (Inventor); Le, Jeanette (Inventor)

2000-01-01

A system for emergency aircraft control uses at least one engine and lateral fuel transfer that allows a pilot to regain control over an aircraft under emergency conditions. Where aircraft propulsion is available only through engines on one side of the aircraft, lateral fuel transfer provides means by which the center of gravity of the aircraft can be moved over to the wing associated with the operating engine, thus inducing a moment that balances the moment from the remaining engine, allowing the pilot to regain control over the aircraft. By implementing the present invention in flight control programming associated with a flight control computer (FCC), control of the aircraft under emergency conditions can be linked to the yoke or autopilot knob of the aircraft. Additionally, the center of gravity of the aircraft can be shifted in order to effect maneuvers and turns by spacing such center of gravity either closer to or farther away from the propelling engine or engines. In an alternative embodiment, aircraft having a third engine associated with the tail section or otherwise are accommodated and implemented by the present invention by appropriately shifting the center of gravity of the aircraft. Alternatively, where a four-engine aircraft has suffered loss of engine control on one side of the plane, the lateral fuel transfer may deliver the center of gravity closer to the two remaining engines. Differential thrust between the two can then control the pitch and roll of the aircraft in conjunction with lateral fuel transfer.

Bacterial communities in commercial aircraft high-efficiency particulate air (HEPA) filters assessed by PhyloChip analysis.

PubMed

Korves, T M; Piceno, Y M; Tom, L M; Desantis, T Z; Jones, B W; Andersen, G L; Hwang, G M

2013-02-01

Air travel can rapidly transport infectious diseases globally. To facilitate the design of biosensors for infectious organisms in commercial aircraft, we characterized bacterial diversity in aircraft air. Samples from 61 aircraft high-efficiency particulate air (HEPA) filters were analyzed with a custom microarray of 16S rRNA gene sequences (PhyloChip), representing bacterial lineages. A total of 606 subfamilies from 41 phyla were detected. The most abundant bacterial subfamilies included bacteria associated with humans, especially skin, gastrointestinal and respiratory tracts, and with water and soil habitats. Operational taxonomic units that contain important human pathogens as well as their close, more benign relatives were detected. When compared to 43 samples of urban outdoor air, aircraft samples differed in composition, with higher relative abundance of Firmicutes and Gammaproteobacteria lineages in aircraft samples, and higher relative abundance of Actinobacteria and Betaproteobacteria lineages in outdoor air samples. In addition, aircraft and outdoor air samples differed in the incidence of taxa containing human pathogens. Overall, these results demonstrate that HEPA filter samples can be used to deeply characterize bacterial diversity in aircraft air and suggest that the presence of close relatives of certain pathogens must be taken into account in probe design for aircraft biosensors. A biosensor that could be deployed in commercial aircraft would be required to function at an extremely low false alarm rate, making an understanding of microbial background important. This study reveals a diverse bacterial background present on aircraft, including bacteria closely related to pathogens of public health concern. Furthermore, this aircraft background is different from outdoor air, suggesting different probes may be needed to detect airborne contaminants to achieve minimal false alarm rates. This study also indicates that aircraft HEPA filters could be used with other molecular techniques to further characterize background bacteria and in investigations in the wake of a disease outbreak. © 2012 John Wiley & Sons A/S.

Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

PubMed

Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

2011-05-01

Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max

Surface modeling method for aircraft engine blades by using speckle patterns based on the virtual stereo vision system

NASA Astrophysics Data System (ADS)

Yu, Zhijing; Ma, Kai; Wang, Zhijun; Wu, Jun; Wang, Tao; Zhuge, Jingchang

2018-03-01

A blade is one of the most important components of an aircraft engine. Due to its high manufacturing costs, it is indispensable to come up with methods for repairing damaged blades. In order to obtain a surface model of the blades, this paper proposes a modeling method by using speckle patterns based on the virtual stereo vision system. Firstly, blades are sprayed evenly creating random speckle patterns and point clouds from blade surfaces can be calculated by using speckle patterns based on the virtual stereo vision system. Secondly, boundary points are obtained in the way of varied step lengths according to curvature and are fitted to get a blade surface envelope with a cubic B-spline curve. Finally, the surface model of blades is established with the envelope curves and the point clouds. Experimental results show that the surface model of aircraft engine blades is fair and accurate.

Toward improved durability in advanced aircraft engine hot sections

NASA Technical Reports Server (NTRS)

Sokolowski, Daniel E. (Editor)

1989-01-01

The conference on durability improvement methods for advanced aircraft gas turbine hot-section components discussed NASA's Hot Section Technology (HOST) project, advanced high-temperature instrumentation for hot-section research, the development and application of combustor aerothermal models, and the evaluation of a data base and numerical model for turbine heat transfer. Also discussed are structural analysis methods for gas turbine hot section components, fatigue life-prediction modeling for turbine hot section materials, and the service life modeling of thermal barrier coatings for aircraft gas turbine engines.

STOVL Control Integration Program

NASA Technical Reports Server (NTRS)

Weiss, C.; Mcdowell, P.; Watts, S.

1994-01-01

An integrated flight/propulsion control for an advanced vector thrust supersonic STOVL aircraft, was developed by Pratt & Whitney and McDonnell Douglas Aerospace East. The IFPC design was based upon the partitioning of the global requirements into flight control and propulsion control requirements. To validate the design, aircraft and engine models were also developed for use on a NASA Ames piloted simulator. Different flight control implementations, evaluated for their handling qualities, are documented in the report along with the propulsion control, engine model, and aircraft model.

Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

NASA Technical Reports Server (NTRS)

Mascitti, V. R.; Maglieri, D. J. (Editor); Raney, J. P. (Editor)

1979-01-01

NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type.

Workshop on Jet Exhaust Noise Reduction for Tactical Aircraft - NASA Perspective

NASA Technical Reports Server (NTRS)

Huff, Dennis L.; Henderson, Brenda S.

2007-01-01

Jet noise from supersonic, high performance aircraft is a significant problem for takeoff and landing operations near air bases and aircraft carriers. As newer aircraft with higher thrust and performance are introduced, the noise tends to increase due to higher jet exhaust velocities. Jet noise has been a subject of research for over 55 years. Commercial subsonic aircraft benefit from changes to the engine cycle that reduce the exhaust velocities and result in significant noise reduction. Most of the research programs over the past few decades have concentrated on commercial aircraft. Progress has been made by introducing new engines with design features that reduce the noise. NASA has recently started a new program called "Fundamental Aeronautics" where three projects (subsonic fixed wing, subsonic rotary wing, and supersonics) address aircraft noise. For the supersonics project, a primary goal is to understand the underlying physics associated with jet noise so that improved noise prediction tools and noise reduction methods can be developed for a wide range of applications. Highlights from the supersonics project are presented including prediction methods for broadband shock noise, flow measurement methods, and noise reduction methods. Realistic expectations are presented based on past history that indicates significant jet noise reduction cannot be achieved without major changes to the engine cycle. NASA s past experience shows a few EPNdB (effective perceived noise level in decibels) can be achieved using low noise design features such as chevron nozzles. Minimal thrust loss can be expected with these nozzles (< 0.5%) and they may be retrofitted on existing engines. In the long term, it is desirable to use variable cycle engines that can be optimized for lower jet noise during takeoff operations and higher thrust for operational performance. It is also suggested that noise experts be included early in the design process for engine nozzle systems to participate in decisions that may impact the jet noise.

14 CFR 45.13 - Identification data.

Code of Federal Regulations, 2014 CFR

2014-01-01

... any aircraft, aircraft engine, propeller, propeller blade, or propeller hub, without the approval of... paragraph (a) of this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub... this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub other than...

14 CFR 45.13 - Identification data.

Code of Federal Regulations, 2013 CFR

2013-01-01

... any aircraft, aircraft engine, propeller, propeller blade, or propeller hub, without the approval of... paragraph (a) of this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub... this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub other than...

Programs at Wright-patterson Air Force Base

NASA Technical Reports Server (NTRS)

Dayton, Ron

1991-01-01

The Lubrication Branch has two active programs that are developing gas turbine engine mainshaft air/oil seals. Both of these programs, one of which is with General Electric Aircraft Engines and the other with Pratt & Whitney Aircraft, are addressing counter-rotating intershaft applications which involve very high rubbing velocities. The objectives and requirements of these efforts are briefly addressed.

Laser beam propagation through a full scale aircraft turboprop engine exhaust

NASA Astrophysics Data System (ADS)

Henriksson, Markus; Gustafsson, Ove; Sjöqvist, Lars; Seiffer, Dirk; Wendelstein, Norbert

2010-10-01

The exhaust from engines introduces zones of extreme turbulence levels in local environments around aircraft. This may disturb the performance of aircraft mounted optical and laser systems. The turbulence distortion will be especially devastating for optical missile warning and laser based DIRCM systems used to protect manoeuvring aircraft against missile attacks, situations where the optical propagation path may come close to the engine exhaust. To study the extent of the turbulence zones caused by the engine exhaust and the strength of the effects on optical propagation through these zones a joint trial between Germany, the Netherlands, Sweden and the United Kingdom was performed using a medium sized military turboprop transport aircraft tethered to the ground at an airfield. This follows on earlier trials performed on a down-scaled jet-engine test rig. Laser beams were propagated along the axis of the aircraft at different distances relative to the engine exhaust and the spatial beam profiles and intensity scintillations were recorded with cameras and photodiodes. A second laser beam path was directed from underneath the loading ramp diagonally past one of the engines. The laser wavelengths used were 1.5 and 3.6 μm. In addition to spatial beam profile distortions temporal effects were investigated. Measurements were performed at different propeller speeds and at different distances from exhaust nozzle to the laser path. Significant increases in laser beam wander and long term beam radius were observed with the engine running. Corresponding increases were also registered in the scintillation index and the temporal fluctuations of the instantaneous power collected by the detector.

Intelligent Life-Extending Controls for Aircraft Engines Studied

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei

2005-01-01

Current aircraft engine controllers are designed and operated to provide desired performance and stability margins. Except for the hard limits for extreme conditions, engine controllers do not usually take engine component life into consideration during the controller design and operation. The end result is that aircraft pilots regularly operate engines under unnecessarily harsh conditions to strive for optimum performance. The NASA Glenn Research Center and its industrial and academic partners have been working together toward an intelligent control concept that will include engine life as part of the controller design criteria. This research includes the study of the relationship between control action and engine component life as well as the design of an intelligent control algorithm to provide proper tradeoffs between performance and engine life. This approach is expected to maintain operating safety while minimizing overall operating costs. In this study, the thermomechanical fatigue (TMF) of a critical component was selected to demonstrate how an intelligent engine control algorithm can significantly extend engine life with only a very small sacrifice in performance. An intelligent engine control scheme based on modifying the high-pressure spool speed (NH) was proposed to reduce TMF damage from ground idle to takeoff. The NH acceleration schedule was optimized to minimize the TMF damage for a given rise-time constraint, which represents the performance requirement. The intelligent engine control scheme was used to simulate a commercial short-haul aircraft engine.

The Prediction of Unsteady Aerodynamic Loading in High Aspect Ratio Wall Bounded Jets

NASA Astrophysics Data System (ADS)

Lurie, Michael B.

Stealth aircraft are becoming more and more prevalent in the aircraft industry. One of the features of many stealth aircraft is an integrated engine that is mounted above the aircraft fuselage. The engine nozzle is often rectangular with a high aspect ratio, and exhausts onto a jet deck formed by the aircraft fuselage. This configuration allows the aircraft fuselage to shield the noise and other detectable features caused by the engine from the ground. The Northrop Grumman B2 Bomber is perhaps the most well-known example of this configuration. Additionally, stealth technology combined with unmanned aerial vehicles (UAV's) has led to the Joint Unmanned Combat System project, or J-UCAS. Both of the aircraft in development in this project use a wall-bounded high aspect ratio nozzle for stealth purposes. While these engine configurations provide a low radar profile and reduce the noise levels on the ground, they do introduce additional considerations. Since the engine is mounted above the aircraft, the nozzle jet is wall bounded by the fuselage of the aircraft. This is known as the flight deck. The jet stream exiting the nozzle can travel at supersonic speeds and potentially generates shock or expansion waves that impinge on the surface of the deck. The oscillations of these shockwaves on the deck produce localized unsteady forces acting on the aircraft. In addition, the interaction between the high speed jet stream and the slower ambient air causes a shear layer to form from the trailing edge of the nozzle. Turbulent eddies form and increase in size as they move downstream. The interactions of the shear layer with the flight deck produce additional unsteady forces on the aircraft. This thesis presents a study to predict the forces on a flight deck caused by a high aspect ratio wall bounded nozzle using both experimental methods and numerical simulations. The experiments performed were conducted on two different nozzles with aspect ratios of 4-1 and 8-1. Several different run conditions, including subsonic, overexpanded, on-design, and under-expanded, are included to study the effects of Mach number on the unsteady pressure. An aluminum flat plate is used to represent the aft deck. The plate is instrumented with Endevco pressure transducers to capture the fluctuating pressure on the aft deck. A spectral analysis performed on the individual sensors shows that the primary sources of fluctuating pressure are the shear layer along with shock-boundary layer interaction. Additional scaling with the nozzle heights is also presented. The numerical simulations were performed using a fully viscous, hybrid RANS/ LES model. They matched the nozzle characteristics and run conditions performed in the experiment. A detailed comparison between the unsteady pressures predicted by the computational simulations and those measured by the experiment is presented. Several discrepancies between the experimental and numerical results are the result of numerical error caused by the time marching scheme used in the simulations. A proper orthogonal decomposition (POD) method is introduced to further analyze the computational simulations and provide a filtering method to obtain more accurate results.

77 FR 13488 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines AGENCY: Federal Aviation... this AD, contact Thielert Aircraft Engines GmbH, Platanenstrasse 14 D-09350, Lichtenstein, Germany... following new AD: 2010-11-09R1 Thielert Aircraft Engines GmbH: Amendment 39-16972; Docket No. FAA-2009-0201...

Theseus Engine Being Unloaded

NASA Technical Reports Server (NTRS)

1996-01-01

Crew members are seen here unloading an engine of the Theseus prototype research aircraft at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

14 CFR 21.16 - Special conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... standards for an aircraft, aircraft engine, or propeller because of a novel or unusual design feature of the aircraft, aircraft engine or propeller, he prescribes special conditions and amendments thereto for the... safety standards for the aircraft, aircraft engine or propeller as the Administrator finds necessary to...

14 CFR 21.16 - Special conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... standards for an aircraft, aircraft engine, or propeller because of a novel or unusual design feature of the aircraft, aircraft engine or propeller, he prescribes special conditions and amendments thereto for the... safety standards for the aircraft, aircraft engine or propeller as the Administrator finds necessary to...

14 CFR 45.13 - Identification data.

Code of Federal Regulations, 2012 CFR

2012-01-01

... paragraph (a) of this section, on any aircraft, aircraft engine, propeller, propeller blade, or propeller... identification information required by paragraph (a) of this section on any aircraft, aircraft engine, propeller... with paragraph (d)(2) of this section on any aircraft, aircraft engine, propeller, propeller blade, or...

Aircraft engine and auxiliary power unit emissions from combusting JP-8 fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimm, L.T.; Sylvia, D.A.; Gerstle, T.C.

1997-12-31

Due to safety considerations and in an effort to standardize Department of Defense fuels, the US Air Force (USAF) replaced the naptha-based JP-4, MIL-T-5624, with the kerosene-based JP-8, MIL-T-83133, as the standard turbine fuel. Although engine emissions from combustion of JP-4 are well documented for criteria pollutants, little information exists for criteria and hazardous air pollutants from combustion of JP-8 fuel. Due to intrinsic differences between these two raw fuels, their combustion products were expected to differ. As part of a broader engine testing program, the Air Force, through the Human Systems Center at Brooks AFB, TX, has contracted tomore » have the emissions characterized from aircraft engines and auxiliary power units (APUs). Criteria pollutant and targeted HAP emissions of selected USAF aircraft engines were quantified during the test program. Emission test results will be used to develop emission factors for the tested aircraft engines and APUs. The Air Force intends to develop a mathematical relationship, using the data collected during this series of tests and from previous tests, to extrapolate existing JP-4 emission factors to representative JP-8 emission factors for other engines. This paper reports sampling methodologies for the following aircraft engine emissions tests: F110-GE-100, F101-GE-102, TF33-P-102, F108-CF-100, T56-A-15, and T39-GE-1A/C. The UH-60A helicopter engine, T700-GE-700, and the C-5A/B and C-130H auxiliary power units (GTCP165-1 and GTCP85-180, respectively) were also tested. Testing was performed at various engine settings to determine emissions of particulate matter, carbon monoxide, nitrogen oxides, sulfur oxides, total hydrocarbon, and selected hazardous air pollutants. Ambient monitoring was conducted concurrently to establish background pollutant concentrations for data correction.« less

An Integrated Architecture for On-Board Aircraft Engine Performance Trend Monitoring and Gas Path Fault Diagnostics

NASA Technical Reports Server (NTRS)

Simon, Donald L.

2010-01-01

Aircraft engine performance trend monitoring and gas path fault diagnostics are closely related technologies that assist operators in managing the health of their gas turbine engine assets. Trend monitoring is the process of monitoring the gradual performance change that an aircraft engine will naturally incur over time due to turbomachinery deterioration, while gas path diagnostics is the process of detecting and isolating the occurrence of any faults impacting engine flow-path performance. Today, performance trend monitoring and gas path fault diagnostic functions are performed by a combination of on-board and off-board strategies. On-board engine control computers contain logic that monitors for anomalous engine operation in real-time. Off-board ground stations are used to conduct fleet-wide engine trend monitoring and fault diagnostics based on data collected from each engine each flight. Continuing advances in avionics are enabling the migration of portions of the ground-based functionality on-board, giving rise to more sophisticated on-board engine health management capabilities. This paper reviews the conventional engine performance trend monitoring and gas path fault diagnostic architecture commonly applied today, and presents a proposed enhanced on-board architecture for future applications. The enhanced architecture gains real-time access to an expanded quantity of engine parameters, and provides advanced on-board model-based estimation capabilities. The benefits of the enhanced architecture include the real-time continuous monitoring of engine health, the early diagnosis of fault conditions, and the estimation of unmeasured engine performance parameters. A future vision to advance the enhanced architecture is also presented and discussed

Comparison of complementary and Kalman filter based data fusion for attitude heading reference system

NASA Astrophysics Data System (ADS)

Islam, Tariqul; Islam, Md. Saiful; Shajid-Ul-Mahmud, Md.; Hossam-E-Haider, Md

2017-12-01

An Attitude Heading Reference System (AHRS) provides 3D orientation of an aircraft (roll, pitch, and yaw) with instantaneous position and also heading information. For implementation of a low cost AHRS system Micro-electrical-Mechanical system (MEMS) based sensors are used such as accelerometer, gyroscope, and magnetometer. Accelerometers suffer from errors caused by external accelerations that sums to gravity and make accelerometers based rotation inaccurate. Gyroscopes can remove such errors but create drifting problems. So for getting the precise data additionally two very common and well known filters Complementary and Kalman are introduced to the system. In this paper a comparison of system performance using these two filters is shown separately so that one would be able to select filter with better performance for his/her system.

CID Aircraft post-impact lakebed skid

NASA Technical Reports Server (NTRS)

1984-01-01

Moments after hitting and sliding through the wing openers the aircraft burst into flame, with a spectacular fireball seen emanating from the right inboard engine area. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

14 CFR 21.33 - Inspection and tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) No aircraft, aircraft engine, propeller, or part thereof may be presented to the Administrator for... aircraft, aircraft engine, propeller, or part thereof; and (2) No change may be made to an aircraft, aircraft engine, propeller, or part thereof between the time that compliance with paragraphs (b)(2) through...

14 CFR 21.16 - Special conditions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... aircraft, aircraft engine, or propeller because of a novel or unusual design feature of the aircraft, aircraft engine or propeller, he prescribes special conditions and amendments thereto for the product. The... for the aircraft, aircraft engine or propeller as the FAA finds necessary to establish a level of...

14 CFR 21.16 - Special conditions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... aircraft, aircraft engine, or propeller because of a novel or unusual design feature of the aircraft, aircraft engine or propeller, he prescribes special conditions and amendments thereto for the product. The... for the aircraft, aircraft engine or propeller as the FAA finds necessary to establish a level of...

14 CFR 21.16 - Special conditions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... aircraft, aircraft engine, or propeller because of a novel or unusual design feature of the aircraft, aircraft engine or propeller, he prescribes special conditions and amendments thereto for the product. The... for the aircraft, aircraft engine or propeller as the FAA finds necessary to establish a level of...

14 CFR 21.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... purposes of this part, the word “product” means an aircraft, aircraft engine, or propeller. In addition... a document issued by the FAA for an aircraft, aircraft engine, propeller, or article which certifies that the aircraft, aircraft engine, propeller, or article conforms to its approved design and is in a...

Advanced online control mode selection for gas turbine aircraft engines

NASA Astrophysics Data System (ADS)

Wiseman, Matthew William

The modern gas turbine aircraft engine is a complex, highly nonlinear system the operates in a widely varying environment. Traditional engine control techniques based on the hydro mechanical control concepts of early turbojet engines are unable to deliver the performance required from today's advanced engine designs. A new type of advanced control utilizing multiple control modes and an online mode selector is investigated, and various strategies for improving the baseline mode selection architecture are introduced. The ability to five-tune actuator command outputs is added to the basic mode selection and blending process, and mode selection designs that we valid for the entire flight envelope are presented. Methods for optimizing the mode selector to improve overall engine performance are also discussed. Finally, using flight test data from a GE F110-powered F16 aircraft, the full-envelope mode selector designs are validated and shown to provide significant performance benefits. Specifically, thrust command tracking is enhanced while critical engine limits are protected, with very little impact on engine efficiency.

A method to estimate weight and dimensions of aircraft gas turbine engines. Volume 1: Method of analysis

NASA Technical Reports Server (NTRS)

Pera, R. J.; Onat, E.; Klees, G. W.; Tjonneland, E.

1977-01-01

Weight and envelope dimensions of aircraft gas turbine engines are estimated within plus or minus 5% to 10% using a computer method based on correlations of component weight and design features of 29 data base engines. Rotating components are estimated by a preliminary design procedure where blade geometry, operating conditions, material properties, shaft speed, hub-tip ratio, etc., are the primary independent variables used. The development and justification of the method selected, the various methods of analysis, the use of the program, and a description of the input/output data are discussed.

Proceedings of the 1987 Aircraft/Engine Structural Integrity Program (ASIP/ENSIP) Conference Held in the Hilton Palacio del Rio Hotel, San Antonio, Texas 1-3 December 1987

DTIC Science & Technology

1988-06-01

upgrading of the depot’s FPI inspection facility, In the forme- case, a realistic projection based while augmenting it with enhanced inspection systems...number of models, powers the twin engined F-15 and the single engined F-16 fighter aircraft. It is an augmented turbofan engine in the 25,000 pound...move from an idea in 1972 to reality today for military gas turbine engines. Special acknowledgement is accorded to the Materials Laboratory of the Air

Randomized path optimization for thevMitigated counter detection of UAVS

DTIC Science & Technology

2017-06-01

using Bayesian filtering . The KL divergence is used to compare the probability density of aircraft termination to a normal distribution around the...Bayesian filtering . The KL divergence is used to compare the probability density of aircraft termination to a normal distribution around the true terminal...algorithm’s success. A recursive Bayesian filtering scheme is used to assimilate noisy measurements of the UAVs position to predict its terminal location. We

Application of a modified complementary filtering technique for increased aircraft control system frequency bandwidth in high vibration environment

NASA Technical Reports Server (NTRS)

Garren, J. F., Jr.; Niessen, F. R.; Abbott, T. S.; Yenni, K. R.

1977-01-01

A modified complementary filtering technique for estimating aircraft roll rate was developed and flown in a research helicopter to determine whether higher gains could be achieved. Use of this technique did, in fact, permit a substantial increase in system frequency bandwidth because, in comparison with first-order filtering, it reduced both noise amplification and control limit-cycle tendencies.

Development and Deployment of an Aerospace Recommended Practice (ARP) Compliant Measurement System for nvPM Certification Measurements of Aircraft Engines - Current Status.

NASA Astrophysics Data System (ADS)

Whitefield, P. D.; Hagen, D. E.; Lobo, P.; Miake-Lye, R. C.

2015-12-01

The Society of Automotive Engineers (SAE) Aircraft Exhaust Emissions Measurement Committee (E-31) has published an Aerospace Information Report (AIR) 6241 detailing the sampling system for the measurement of non-volatile particulate matter (nvPM) from aircraft engines (SAE 2013). The system is designed to operate in parallel with existing International Civil Aviation Organization (ICAO) Annex 16 compliant combustion gas sampling systems used for emissions certification from aircraft engines captured by conventional (Annex 16) gas sampling rakes (ICAO, 2008). The SAE E-31 committee is also working to ballot an Aerospace Recommended Practice (ARP) that will provide the methodology and system specification to measure nvPM from aircraft engines. The ARP is currently in preparation and is expected to be ready for ballot in 2015. A prototype AIR-compliant nvPM measurement system - The North American Reference System (NARS) has been built and evaluated at the MSTCOE under the joint sponsorship of the FAA, EPA and Transport Canada. It has been used to validate the performance characteristics of OEM AIR-compliant systems and is being used in engine certification type testing at OEM facilities to obtain data from a set of representative engines in the fleet. The data collected during these tests will be used by ICAO/CAEP/WG3/PMTG to develop a metric on which on the regulation for nvPM emissions will be based. This paper will review the salient features of the NARS including: (1) emissions sample transport from probe tip to the key diagnostic tools, (2) the mass and number-based diagnostic tools for nvPM mass and number concentration measurement and (3) methods employed to assess the extent of nvPM loss throughout the sampling system. This paper will conclude with a discussion of the recent results from inter-comparison studies conducted with other US - based systems that gives credence to the ARP's readiness for ballot.

14 CFR 21.33 - Inspection and tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... However, unless otherwise authorized by the Administrator— (1) No aircraft, aircraft engine, propeller, or...) through (b)(4) of this section has been shown for that aircraft, aircraft engine, propeller, or part thereof; and (2) No change may be made to an aircraft, aircraft engine, propeller, or part thereof between...

14 CFR 21.1 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... purposes of this part, the word “product” means an aircraft, aircraft engine, or propeller. In addition... document issued by the FAA for an aircraft, aircraft engine, propeller, or article which certifies that the aircraft, aircraft engine, propeller, or article conforms to its approved design and is in a condition for...

Optimal Discrete Event Supervisory Control of Aircraft Gas Turbine Engines

NASA Technical Reports Server (NTRS)

Litt, Jonathan (Technical Monitor); Ray, Asok

2004-01-01

This report presents an application of the recently developed theory of optimal Discrete Event Supervisory (DES) control that is based on a signed real measure of regular languages. The DES control techniques are validated on an aircraft gas turbine engine simulation test bed. The test bed is implemented on a networked computer system in which two computers operate in the client-server mode. Several DES controllers have been tested for engine performance and reliability.

Development of an optimal automatic control law and filter algorithm for steep glideslope capture and glideslope tracking

NASA Technical Reports Server (NTRS)

Halyo, N.

1976-01-01

A digital automatic control law to capture a steep glideslope and track the glideslope to a specified altitude is developed for the longitudinal/vertical dynamics of a CTOL aircraft using modern estimation and control techniques. The control law uses a constant gain Kalman filter to process guidance information from the microwave landing system, and acceleration from body mounted accelerometer data. The filter outputs navigation data and wind velocity estimates which are used in controlling the aircraft. Results from a digital simulation of the aircraft dynamics and the control law are presented for various wind conditions.

Response Sensitivity of Typical Aircraft Jet Engine Fan Blade-Like Structures to Bird Impacts.

DTIC Science & Technology

1982-05-01

AIRCRAFT ENGINE BU--ETC F/G 21/5 RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -L...SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -LIKE STRUCTURES TO BIRD IMPACTS David P. Bauer Robert S. Bertke University of Dayton Research...COVERED RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT FINAL REPORT JET ENGINE FAN BLADE -LIKE STRUCTURES Oct. 1977 to Jan. 1979 TO BIRD IMPACTS s.

Emissions of piston engine aircraft using aviation gasoline (avgas) and motor gasoline (mogas) as fuel – a review

NASA Astrophysics Data System (ADS)

Thanikasalam, K.; Rahmat, M.; Fahmi, A. G. Mohammad; Zulkifli, A. M.; Shawal, N. Noor; Ilanchelvi, K.; Ananth, M.; Elayarasan, R.

2018-05-01

There are two categories of aircraft engines, namely, piston and gas turbine engines. Piston engine extracts energy from a combustion compartment through a piston and crank apparatus that engages the propellers, which in turn, provides an aircraft the needed momentum. On the other hand, gas turbine engine heats a compressed air in the combustion compartment resulting in propulsion that drives an aircraft. Piston engine aircrafts might appear small but together thousands of piston engine aircraft, which encompasses a bulk of the general aviation fleet, present a considerable health threat. That is because these aircraft, which depend on avgas and mogas to run, comprise major remaining sources of lead emissions. People exposed to even small levels of lead, particularly children, have tendencies to suffer from cognitive and neurological harm. Dissimilar from commercial airliners that do not utilize leaded fuels, piston engine aircraft account for nearly half of the lead discharge in skies. But, what is the extent of the impact caused by these airborne emissions on the country’s economy and public health? To answer this query, a thorough literature review on emissions of piston engine aircraft ought to be undertaken. This article conducts a literature review on emissions of piston engine aircraft using avgas as fuel and mogas as fuel.

Jet fuel based high pressure solid oxide fuel cell system

NASA Technical Reports Server (NTRS)

Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

2013-01-01

A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

NASA Technical Reports Server (NTRS)

Srinivasan, Hari (Inventor); Hardin, Larry (Inventor); Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Dasgupta, Arindam (Inventor); Bayt, Robert (Inventor)

2015-01-01

A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

CID Aircraft slap-down

NASA Technical Reports Server (NTRS)

1984-01-01

In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

Controlled Impact Demonstration instrumented test dummies installed in plane

NASA Technical Reports Server (NTRS)

1984-01-01

In this photograph are seen some of dummies in the passenger cabin of the B-720 aircraft. NASA Langley Research Center instrumented a large portion of the aircraft and the dummies for loads in a crashworthiness research program. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Adimistration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive called Anti-misting Kerosene (AMK) designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

Further studies using matched filter theory and stochastic simulation for gust loads prediction

NASA Technical Reports Server (NTRS)

Scott, Robert C.; Pototzky, Anthony S.; Perry, Boyd Iii

1993-01-01

This paper describes two analysis methods -- one deterministic, the other stochastic -- for computing maximized and time-correlated gust loads for aircraft with nonlinear control systems. The first method is based on matched filter theory; the second is based on stochastic simulation. The paper summarizes the methods, discusses the selection of gust intensity for each method and presents numerical results. A strong similarity between the results from the two methods is seen to exist for both linear and nonlinear configurations.

Research on hypersonic aircraft using pre-cooled turbojet engines

NASA Astrophysics Data System (ADS)

Taguchi, Hideyuki; Kobayashi, Hiroaki; Kojima, Takayuki; Ueno, Atsushi; Imamura, Shunsuke; Hongoh, Motoyuki; Harada, Kenya

2012-04-01

Systems analysis of a Mach 5 class hypersonic aircraft is performed. The aircraft can fly across the Pacific Ocean in 2 h. A multidisciplinary optimization program for aerodynamics, structure, propulsion, and trajectory is used in the analysis. The result of each element model is improved using higher accuracy analysis tools. The aerodynamic performance of the hypersonic aircraft is examined through hypersonic wind tunnel tests. A thermal management system based on the data of the wind tunnel tests is proposed. A pre-cooled turbojet engine is adopted as the propulsion system for the hypersonic aircraft. The engine can be operated continuously from take-off to Mach 5. This engine uses a pre-cooling cycle using cryogenic liquid hydrogen. The high temperature inlet air of hypersonic flight would be cooled by the same liquid hydrogen used as fuel. The engine is tested under sea level static conditions. The engine is installed on a flight test vehicle. Both liquid hydrogen fuel and gaseous hydrogen fuel are supplied to the engine from a tank and cylinders installed within the vehicle. The designed operation of major components of the engine is confirmed. A large amount of liquid hydrogen is supplied to the pre-cooler in order to make its performance sufficient for Mach 5 flight. Thus, fuel rich combustion is adopted at the afterburner. The experiments are carried out under the conditions that the engine is mounted upon an experimental airframe with both set up either horizontally or vertically. As a result, the operating procedure of the pre-cooled turbojet engine is demonstrated.

Study of advanced rotary combustion engines for commuter aircraft

NASA Technical Reports Server (NTRS)

Berkowitz, M.; Jones, C.; Myers, D.

1983-01-01

Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

14 CFR 21.21 - Issue of type certificate: normal, utility, acrobatic, commuter, and transport category aircraft...

Code of Federal Regulations, 2014 CFR

2014-01-01

...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...; manned free balloons; special classes of aircraft; aircraft engines; propellers. An applicant is entitled... category, or for a manned free balloon, special class of aircraft, or an aircraft engine or propeller, if...

14 CFR 21.21 - Issue of type certificate: normal, utility, acrobatic, commuter, and transport category aircraft...

Code of Federal Regulations, 2010 CFR

2010-01-01

...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...; manned free balloons; special classes of aircraft; aircraft engines; propellers. Link to an amendment..., special class of aircraft, or an aircraft engine or propeller, if— (a) The product qualifies under § 21.27...

14 CFR 21.21 - Issue of type certificate: normal, utility, acrobatic, commuter, and transport category aircraft...

Code of Federal Regulations, 2013 CFR

2013-01-01

...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...; manned free balloons; special classes of aircraft; aircraft engines; propellers. An applicant is entitled... category, or for a manned free balloon, special class of aircraft, or an aircraft engine or propeller, if...

14 CFR 21.21 - Issue of type certificate: normal, utility, acrobatic, commuter, and transport category aircraft...

Code of Federal Regulations, 2012 CFR

2012-01-01

...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...; manned free balloons; special classes of aircraft; aircraft engines; propellers. An applicant is entitled... category, or for a manned free balloon, special class of aircraft, or an aircraft engine or propeller, if...

Atomization and combustion performance of antimisting kerosene and jet fuel

NASA Technical Reports Server (NTRS)

Fleeter, R.; Parikh, P.; Sarohia, V.

1983-01-01

Combustion performance of antimisting kerosene (AMK) containing FM-9 polymer was investigated at various levels of degradation (restoration of AMK for normal use in a gas turbine engine). To establish the relationship of degradation and atomization to performance in an aircraft gas turbine combustor, sprays formed by the nozzle of a JT8-D combustor with Jet A and AMK at 1 atmosphere (atm) (14.1 lb/square in absolute) pressure and 22 C at several degradation levels were analyzed. A new spray characterization technique based on digital image analysis of high resolution, wide field spray images formed under pulsed ruby laser sheet illumination was developed. Combustion tests were performed for these fuels in a JT8-D single can combustor facility to measure combustion efficiency and the lean extinction limit. Correlation of combustion performance under simulated engine operating conditions with nozzle spray Sauter mean diameter (SMD) measured at 1 atm and 22 C were observed. Fuel spray SMD and hence the combustion efficiency are strongly influenced by fuel degradation level. Use of even the most highly degraded AMK tested (filter ratio = 1.2) resulted in an increase in fuel consumption of 0.08% to 0.20% at engine cruise conditions.

14 CFR 49.51 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRCRAFT TITLES AND SECURITY DOCUMENTS Encumbrances Against Air Carrier Aircraft Engines, Propellers... aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare...

14 CFR 49.51 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRCRAFT TITLES AND SECURITY DOCUMENTS Encumbrances Against Air Carrier Aircraft Engines, Propellers... aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare...

14 CFR 49.51 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRCRAFT TITLES AND SECURITY DOCUMENTS Encumbrances Against Air Carrier Aircraft Engines, Propellers... aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare...

14 CFR 49.51 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRCRAFT TITLES AND SECURITY DOCUMENTS Encumbrances Against Air Carrier Aircraft Engines, Propellers... aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare...

14 CFR 49.51 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRCRAFT TITLES AND SECURITY DOCUMENTS Encumbrances Against Air Carrier Aircraft Engines, Propellers... aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare...

Alternative aircraft fuels technology

NASA Technical Reports Server (NTRS)

Grobman, J.

1976-01-01

NASA is studying the characteristics of future aircraft fuels produced from either petroleum or nonpetroleum sources such as oil shale or coal. These future hydrocarbon based fuels may have chemical and physical properties that are different from present aviation turbine fuels. This research is aimed at determining what those characteristics may be, how present aircraft and engine components and materials would be affected by fuel specification changes, and what changes in both aircraft and engine design would be required to utilize these future fuels without sacrificing performance, reliability, or safety. This fuels technology program was organized to include both in-house and contract research on the synthesis and characterization of fuels, component evaluations of combustors, turbines, and fuel systems, and, eventually, full-scale engine demonstrations. A review of the various elements of the program and significant results obtained so far are presented.

Method and system for monitoring and displaying engine performance parameters

NASA Technical Reports Server (NTRS)

Abbott, Terence S. (Inventor); Person, Lee H., Jr. (Inventor)

1988-01-01

The invention is believed a major improvement that will have a broad application in governmental and commercial aviation. It provides a dynamic method and system for monitoring and simultaneously displaying in easily scanned form the available, predicted, and actual thrust of a jet aircraft engine under actual operating conditions. The available and predicted thrusts are based on the performance of a functional model of the aircraft engine under the same operating conditions. Other critical performance parameters of the aircraft engine and functional model are generated and compared, the differences in value being simultaneously displayed in conjunction with the displayed thrust values. Thus, the displayed information permits the pilot to make power adjustments directly while keeping him aware of total performance at a glance of a single display panel.

High Reliability Engine Control Demonstrated for Aircraft Engines

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei

1999-01-01

For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

40 CFR 87.20 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.20 Applicability. The provisions of this subpart are applicable to all aircraft gas turbine engines of the classes...

40 CFR 87.30 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (In-Use Aircraft Gas Turbine Engines) § 87.30 Applicability. The provisions of this subpart are applicable to all in-use aircraft gas turbine engines...

40 CFR 87.20 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.20 Applicability. The provisions of this subpart are applicable to all aircraft gas turbine engines of the classes...

40 CFR 87.30 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (In-Use Aircraft Gas Turbine Engines) § 87.30 Applicability. The provisions of this subpart are applicable to all in-use aircraft gas turbine engines...

40 CFR 87.20 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.20 Applicability. The provisions of this subpart are applicable to all aircraft gas turbine engines of the classes...

40 CFR 87.20 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.20 Applicability. The provisions of this subpart are applicable to all aircraft gas turbine engines of the classes...

40 CFR 87.30 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (In-Use Aircraft Gas Turbine Engines) § 87.30 Applicability. The provisions of this subpart are applicable to all in-use aircraft gas turbine engines...

40 CFR 87.30 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (In-Use Aircraft Gas Turbine Engines) § 87.30 Applicability. The provisions of this subpart are applicable to all in-use aircraft gas turbine engines...

14 CFR 34.71 - Compliance with gaseous emission standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.71... Protection, Volume II, Aircraft Engine Emissions, Second Edition, July 1993, effective July 26, 1993...

14 CFR 34.71 - Compliance with gaseous emission standards.

Code of Federal Regulations, 2011 CFR

2011-01-01

... TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.71... Protection, Volume II, Aircraft Engine Emissions, Second Edition, July 1993, effective July 26, 1993...

14 CFR 21.502 - Approval of materials, parts, and appliances.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Approval of Engines, Propellers... N—Acceptance of Aircraft Engines, Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or...

Active Suppression of Instabilities in Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George

2004-01-01

A method of feedback control has been proposed as a means of suppressing thermo-acoustic instabilities in a liquid- fueled combustor of a type used in an aircraft engine. The basic principle of the method is one of (1) sensing combustor pressure oscillations associated with instabilities and (2) modulating the rate of flow of fuel to the combustor with a control phase that is chosen adaptively so that the pressure oscillations caused by the modulation oppose the sensed pressure oscillations. The need for this method arises because of the planned introduction of advanced, lean-burning aircraft gas turbine engines, which promise to operate with higher efficiencies and to emit smaller quantities of nitrogen oxides, relative to those of present aircraft engines. Unfortunately, the advanced engines are more susceptible to thermoacoustic instabilities. These instabilities are hard to control because they include large dead-time phase shifts, wide-band noise characterized by amplitudes that are large relative to those of the instabilities, exponential growth of the instabilities, random net phase walks, and amplitude fluctuations. In this method (see figure), the output of a combustion-pressure sensor would be wide-band-pass filtered and then further processed to generate a control signal that would be applied to a fast-actuation valve to modulate the flow of fuel. Initially, the controller would rapidly take large phase steps in order to home in, within a fraction of a second, to a favorable phase region within which the instability would be reduced. Then the controller would restrict itself to operate within this phase region and would further restrict itself to operate within a region of stability, as long as the power in the instability signal was decreasing. In the phase-shifting scheme of this method, the phase of the control vector would be made to continuously bounce back and forth from one boundary of an effective stability region to the other. Computationally, this scheme would be implemented by the adaptive sliding phaser averaged control (ASPAC) algorithm, which requires very little detailed knowledge of the combustor dynamics. In the ASPAC algorithm, the power of the instability signal would be calculated from the wide-bandpass- filtered combustion-pressure signal and averaged over a period of time (typically of the order of a few hundredths of a second) corresponding to the controller updating cycle [not to be confused with the controller sampling cycle, which would be much shorter (typically of the order of 10(exp -4) second)].

Jet engine exhaust emissions of high altitude commercial aircraft projected to 1990

NASA Technical Reports Server (NTRS)

Grobman, J.; Ingebo, R. D.

1974-01-01

Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high-altitude cruise conditions are presented. The forecasts are based on:(1) current knowledge of emission characteristics of combustors and augmentors; (2) the status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft fueled by either JP fuel, liquefied natural gas, or hydrogen. Results are presented for cruise conditions in terms of both an emission index (g constituent/kg fuel) and an emission rate (g constituent/hr).

Study of cabin noise control for twin engine general aviation aircraft

NASA Astrophysics Data System (ADS)

Vaicaitis, R.; Slazak, M.

1982-02-01

An analytical model based on modal analysis was developed to predict the noise transmission into a twin-engine light aircraft. The model was applied to optimize the interior noise to an A-weighted level of 85 dBA. To achieve the required noise attenuation, add-on treatments in the form of honeycomb panels, damping tapes, acoustic blankets, septum barriers and limp trim panels were added to the existing structure. The added weight of the noise control treatment is about 1.1 percent of the total gross take-off weight of the aircraft.

Hydrogen for the subsonic transport. [aircraft design and fuel requirements

NASA Technical Reports Server (NTRS)

Korycinski, P. F.; Snow, D. B.

1975-01-01

Relations between air travel and fuel requirements are examined. Alternate fuels considered in connection with problems related to a diminishing supply of petroleum include synthetic jet fuel, methane, and hydrogen. A cruise flight of a subsonic aircraft on a hydrogen-fueled jet engine was demonstrated in 1957. However, more development work is required to provide a sound engineering base for a complete air transportation system using hydrogen as fuel. Aircraft designs for alternate fuels are discussed, giving attention to hydrogen-related technology already available and new developments which are needed.

Cabin Noise Control for Twin Engine General Aviation Aircraft

NASA Technical Reports Server (NTRS)

Vaicaitis, R.; Slazak, M.

1982-01-01

An analytical model based on modal analysis was developed to predict the noise transmission into a twin-engine light aircraft. The model was applied to optimize the interior noise to an A-weighted level of 85 dBA. To achieve the required noise attenuation, add-on treatments in the form of honeycomb panels, damping tapes, acoustic blankets, septum barriers and limp trim panels were added to the existing structure. The added weight of the noise control treatment is about 1.1 percent of the total gross take-off weight of the aircraft.

Theseus in Flight

NASA Technical Reports Server (NTRS)

1996-01-01

The twin pusher engines of the prototype Theseus research aircraft can be clearly seen in this photo of the aircraft during a 1996 research flight from the Dryden Flight Research Center, Edwards, California. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

Motion-base simulator study of control of an externally blown flap STOL transport aircraft after failure of an outboard engine during landing approach

NASA Technical Reports Server (NTRS)

Middleton, D. B.; Hurt, G. J., Jr.; Bergeron, H. P.; Patton, J. M., Jr.; Deal, P. L.; Champine, R. A.

1975-01-01

A moving-base simulator investigation of the problems of recovery and landing of a STOL aircraft after failure of an outboard engine during final approach was made. The approaches were made at 75 knots along a 6 deg glide slope. The engine was failed at low altitude and the option to go around was not allowed. The aircraft was simulated with each of three control systems, and it had four high-bypass-ratio fan-jet engines exhausting against large triple-slotted wing flaps to produce additional lift. A virtual-image out-the-window television display of a simulated STOL airport was operating during part of the investigation. Also, a simple heads-up flight director display superimposed on the airport landing scene was used by the pilots to make some of the recoveries following an engine failure. The results of the study indicated that the variation in visual cues and/or motion cues had little effect on the outcome of a recovery, but they did have some effect on the pilot's response and control patterns.

A Kalman Filter Integrated Navigation Design for the IAR Twin Otter Atmospheric Research Aircraft (Methode de Navigation Integree a Filtre de Kalman Destinee au Twin Otter de L’Ira Charge des Recherches Atmospheriques)

DTIC Science & Technology

1991-04-01

1Z I III i II1’I’ ,, iiII ll~ I! ’i tiNt $W"T" INSTITUTE FOR AEROSPACE RESEARCH SCIENTIFIC AND TECHNICAL PUBLICATIONS AERONAUTICAL REPORTS...Aeronautical Reports (LR): Scientific and technical information pertaining to aeronautics considered important, complete, and a lasting contribution to existing...knowledge. Mechanical Engineering Reports (MS): Scientific and technical information pertaining to investigations outside aeronautics considered

New method of calculating the power at altitude of aircraft engines equipped with superchargers on the basis of tests made under sea-level conditions

NASA Technical Reports Server (NTRS)

Sarracino, Marcello

1941-01-01

The present article deals with what is considered to be a simpler and more accurate method of determining, from the results of bench tests under approved rating conditions, the power at altitude of a supercharged aircraft engine, without application of correction formulas. The method of calculating the characteristics at altitude, of supercharged engines, based on the consumption of air, is a more satisfactory and accurate procedure, especially at low boost pressures.

14 CFR 33.61 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.61 Applicability. This subpart prescribes additional design and construction requirements for turbine aircraft engines. ...

14 CFR 33.61 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.61 Applicability. This subpart prescribes additional design and construction requirements for turbine aircraft engines. ...

14 CFR 33.41 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.41 Applicability. This subpart prescribes the block tests and inspections for reciprocating aircraft engines. ...

Extractive sampling and optical remote sensing of F100 aircraft engine emissions.

PubMed

Cowen, Kenneth; Goodwin, Bradley; Joseph, Darrell; Tefend, Matthew; Satola, Jan; Kagann, Robert; Hashmonay, Ram; Spicer, Chester; Holdren, Michael; Mayfield, Howard

2009-05-01

The Strategic Environmental Research and Development Program (SERDP) has initiated several programs to develop and evaluate techniques to characterize emissions from military aircraft to meet increasingly stringent regulatory requirements. This paper describes the results of a recent field study using extractive and optical remote sensing (ORS) techniques to measure emissions from six F-15 fighter aircraft. Testing was performed between November 14 and 16, 2006 on the trim-pad facility at Tyndall Air Force Base in Panama City, FL. Measurements were made on eight different F100 engines, and the engines were tested on-wing of in-use aircraft. A total of 39 test runs were performed at engine power levels that ranged from idle to military power. The approach adopted for these tests involved extractive sampling with collocated ORS measurements at a distance of approximately 20-25 nozzle diameters downstream of the engine exit plane. The emission indices calculated for carbon dioxide, carbon monoxide, nitric oxide, and several volatile organic compounds showed very good agreement when comparing the extractive and ORS sampling methods.

New methodology for modeling annual-aircraft emissions at airports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodmansey, B.G.; Patterson, J.G.

An as-accurate-as-possible estimation of total-aircraft emissions are an essential component of any environmental-impact assessment done for proposed expansions at major airports. To determine the amount of emissions generated by aircraft using present models it is necessary to know the emission characteristics of all engines that are on all planes using the airport. However, the published data base does not cover all engine types and, therefore, a new methodology is needed to assist in estimating annual emissions from aircraft at airports. Linear regression equations relating quantity of emissions to aircraft weight using a known-fleet mix are developed in this paper. Total-annualmore » emissions for CO, NO[sub x], NMHC, SO[sub x], CO[sub 2], and N[sub 2]O are tabulated for Toronto's international airport for 1990. The regression equations are statistically significant for all emissions except for NMHC from large jets and NO[sub x] and NMHC for piston-engine aircraft. This regression model is a relatively simple, fast, and inexpensive method of obtaining an annual-emission inventory for an airport.« less

Constrained Kalman Filtering Via Density Function Truncation for Turbofan Engine Health Estimation

NASA Technical Reports Server (NTRS)

Simon, Dan; Simon, Donald L.

2006-01-01

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter truncates the PDF (probability density function) of the Kalman filter estimate at the known constraints and then computes the constrained filter estimate as the mean of the truncated PDF. The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is demonstrated via simulation results obtained from a turbofan engine model. The turbofan engine model contains 3 state variables, 11 measurements, and 10 component health parameters. It is also shown that the truncated Kalman filter may be a more accurate way of incorporating inequality constraints than other constrained filters (e.g., the projection approach to constrained filtering).

Full-field ultrasonic inspection for a composite sandwich plate skin-core debonding detection using laser-based ultrasonics

NASA Astrophysics Data System (ADS)

Chong, See Yenn; Victor, Jared J.; Todd, Michael D.

2017-04-01

In this paper, a full-field ultrasonic guided wave method is proposed to inspect a composite sandwich specimen made for an aircraft engine nacelle. The back skin/core interface of the specimen is built with two fabricated disbond defects (diameters of 12.7 mm and 25.4 mm) by removing areas of the adhesive used to bond the back skin to the core. A laser ultrasonic interrogation system (LUIS) incorporated with a disbond detection algorithm is developed. The system consists of a 1-kHz laser ultrasonic scanning system and a single fixed ultrasonic sensor to interrogate ultrasonic guided waves in the sandwich specimen. The interest area of 400 mm × 400 mm is scanned at a 0.5 mm scan interval. The corresponding full-field ultrasonic data is obtained and generated in the three-dimensional (3-D) space-time domain. Then, the 3-D full-field ultrasonic data is Fourier transformed and the ultrasonic frequency spectra are analyzed to determine the dominant frequency that is sensitive to the disbond defects. Continuous wavelet transform (CWT) based on fast Fourier transform (FFT) is implemented as a single-frequency bandpass filter to filter the full-field ultrasonic data in the 3-D space-time domain at the selected dominant frequency. The LUIS has shown the ability to detect the disbond with diameters of 11 mm and 23 mm which match to the pre-determined disbond sizes well. For future research, a robust signal processing algorithm and a model-based matched filter will be investigated to make the detection process autonomous and improve detectability

78 FR 63017 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... (NO X ), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet... adopting the gas turbine engine test procedures of the International Civil Aviation Organization (ICAO...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

14 CFR 21.500 - Acceptance of aircraft engines and propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., Propellers, and Articles for Import § 21.500 Acceptance of aircraft engines and propellers. An aircraft engine or propeller manufactured in a foreign country or jurisdiction meets the requirements for... product furnishes with each such aircraft engine or propeller imported into the United States, an export...

Auralization of Hybrid Wing Body Aircraft Flyover Noise from System Noise Predictions

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Aumann, Aric R.; Lopes, Leonvard V.; Burley, Casey L.

2013-01-01

System noise assessments of a state-of-the-art reference aircraft (similar to a Boeing 777-200ER with GE90-like turbofan engines) and several hybrid wing body (HWB) aircraft configurations were recently performed using NASA engine and aircraft system analysis tools. The HWB aircraft were sized to an equivalent mission as the reference aircraft and assessments were performed using measurements of airframe shielding from a series of propulsion airframe aeroacoustic experiments. The focus of this work is to auralize flyover noise from the reference aircraft and the best HWB configuration using source noise predictions and shielding data based largely on the earlier assessments. For each aircraft, three flyover conditions are auralized. These correspond to approach, sideline, and cutback operating states, but flown in straight and level flight trajectories. The auralizations are performed using synthesis and simulation tools developed at NASA. Audio and visual presentations are provided to allow the reader to experience the flyover from the perspective of a listener in the simulated environment.

CID Aircraft pre-impact lakebed skid

NASA Technical Reports Server (NTRS)

1984-01-01

The B-720 is seen viewed moments after impact and just before hitting the wing openers. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

NASA Technical Reports Server (NTRS)

Condon, E. P.; Vedder, J. F.

1984-01-01

Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

Starter/generator testing

NASA Astrophysics Data System (ADS)

Anon

1994-10-01

Sundstrand Aerospace and GE Aircraft Engines have studied the switched reluctance machine for use as an integral starter/generator for future aircraft engines. They have conducted an initial, low-power testing of the starter/generator, which is based on power inverters using IGBT-technology semiconductors, to verify its feasibility in the externally mounted version of the integral starter/generator. This preliminary testing of the 250-kW starter/generator reveals favorable results.

BEST: A Learner-Centered Workplace Literacy Partnership of the Vermont Institute for Self-Reliance and General Electric Aircraft Engines Rutland, VT. Final Performance Report.

ERIC Educational Resources Information Center

Lashof, Judith R.

The Vermont Institute for Self Reliance (VISR) conducted a Basic Educational Skills for Training (BEST) program, a national demonstration project in workplace literacy, from April 1990 to March 1992. BEST provided learner-centered, context-based literacy instruction onsite, on company time, at two General Electric (GE) Aircraft Engines Rutland…

14 CFR Appendix B to Part 43 - Recording of Major Repairs and Major Alterations

Code of Federal Regulations, 2014 CFR

2014-01-01

..., within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for... approval for return to service of the aircraft, airframe, aircraft engine, propeller, or appliance; (3... engine, propeller or appliance. (ii) If an aircraft, the make, model, serial number, nationality and...

14 CFR Appendix B to Part 43 - Recording of Major Repairs and Major Alterations

Code of Federal Regulations, 2011 CFR

2011-01-01

..., within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for... approval for return to service of the aircraft, airframe, aircraft engine, propeller, or appliance; (3... engine, propeller or appliance. (ii) If an aircraft, the make, model, serial number, nationality and...

14 CFR Appendix B to Part 43 - Recording of Major Repairs and Major Alterations

Code of Federal Regulations, 2010 CFR

2010-01-01

..., within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for... approval for return to service of the aircraft, airframe, aircraft engine, propeller, or appliance; (3... engine, propeller or appliance. (ii) If an aircraft, the make, model, serial number, nationality and...

14 CFR Appendix B to Part 43 - Recording of Major Repairs and Major Alterations

Code of Federal Regulations, 2012 CFR

2012-01-01

..., within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for... approval for return to service of the aircraft, airframe, aircraft engine, propeller, or appliance; (3... engine, propeller or appliance. (ii) If an aircraft, the make, model, serial number, nationality and...

Test-engine and inlet performance of an aircraft used for investigating flight effects on fan noise

NASA Technical Reports Server (NTRS)

Golub, R. A.; Preisser, J. S.

1984-01-01

As part of the NASA Flight Effects on Fan Noise Program, a Grumman OV-1B Mohawk aircraft was modified to carry a modified and instrumented Pratt & Whitney JT15D-1 turbofan engine. Onboard flight data, together with simultaneously measured farfield acoustic data, comprise a flight data base to which JT15D-1 static and wind-tunnel data are compared. The overall objective is to improve the ability to use ground-based facilities for the prediction of flight inlet radiated noise. This report describes the hardware and presents performance results for the research engine.

Cobalt: A vital element in the aircraft engine industry

NASA Technical Reports Server (NTRS)

Stephens, J. R.

1981-01-01

Recent trends in the United States consumption of cobalt indicate that superalloys for aircraft engine manufacture require increasing amounts of this strategic element. Superalloys consume a lion's share of total U.S. cobalt usage which was about 16 million pounds in 1980. In excess of 90 percent of the cobalt used in this country was imported, principally from the African countries of Zaire and Zambia. Early studies on the roles of cobalt as an alloying element in high temperature alloys concentrated on the simple Ni-Cr and Nimonic alloy series. The role of cobalt in current complex nickel base superalloys is not well defined and indeed, the need for the high concentration of cobalt in widely used nickel base superalloys is not firmly established. The current cobalt situation is reviewed as it applies to superalloys and the opportunities for research to reduce the consumption of cobalt in the aircraft engine industry are described.

Comparison of Several Methods of Predicting the Pressure Loss at Altitude Across a Baffled Aircraft-Engine Cylinder

NASA Technical Reports Server (NTRS)

Neustein, Joseph; Schafer, Louis J , Jr

1946-01-01

Several methods of predicting the compressible-flow pressure loss across a baffled aircraft-engine cylinder were analytically related and were experimentally investigated on a typical air-cooled aircraft-engine cylinder. Tests with and without heat transfer covered a wide range of cooling-air flows and simulated altitudes from sea level to 40,000 feet. Both the analysis and the test results showed that the method based on the density determined by the static pressure and the stagnation temperature at the baffle exit gave results comparable with those obtained from methods derived by one-dimensional-flow theory. The method based on a characteristic Mach number, although related analytically to one-dimensional-flow theory, was found impractical in the present tests because of the difficulty encountered in defining the proper characteristic state of the cooling air. Accurate predictions of altitude pressure loss can apparently be made by these methods, provided that they are based on the results of sea-level tests with heat transfer.

Noise reduction of a tilt-rotor aircraft including effects on weight and performance

NASA Technical Reports Server (NTRS)

Gibs, J.; Stepniewski, W. Z.; Spencer, R.; Kohler, G.

1973-01-01

Various methods for far-field noise reduction of a tilt-rotor acoustic signature and the performance and weight tradeoffs which result from modification of the noise sources are considered in this report. In order to provide a realistic approach for the investigation, the Boeing tilt-rotor flight research aircraft (Model 222), was selected as the baseline. This aircraft has undergone considerable engineering development. Its rotor has been manufactured and tested in the Ames full-scale wind tunnel. The study reflects the current state-of-the-art of aircraft design for far-field acoustic signature reduction and is not based solely on an engineering feasibility aircraft. This report supplements a previous study investigating reduction of noise signature through the management of the terminal flight trajectory.

Conceptual/preliminary design study of subsonic v/stol and stovl aircraft derivatives of the S-3A

NASA Technical Reports Server (NTRS)

Kidwell, G. H., Jr.

1981-01-01

A computerized aircraft synthesis program was used to examine the feasibility and capability of a V/STOL aircraft based on the Navy S-3A aircraft. Two major airframe modifications are considered: replacement of the wing, and substitution of deflected thrust turbofan engines similar to the Pegasus engine. Three planform configurations for the all composite wing were investigated: an unconstrained span design, a design with the span constrained to 64 feet, and an unconstrained span oblique wing design. Each design was optimized using the same design variables, and performance and control analyses were performed. The oblique wing configuration was found to have the greatest potential in this application. The mission performance of these V/STOL aircraft compares favorably with that of the CTOL S-3A.

Recommendations for field measurements of aircraft noise

NASA Technical Reports Server (NTRS)

Marsh, A. H.

1982-01-01

Specific recommendations for environmental test criteria, data acquisition procedures, and instrument performance requirements for measurement of noise levels produced by aircraft in flight are provided. Recommendations are also given for measurement of associated airplane and engine parameters and atmospheric conditions. Recommendations are based on capabilities which were available commercially in 1981; they are applicable to field tests of aircraft flying subsonically past microphones located near the surface of the ground either directly under or to the side of a flight path. Aircraft types covered by the recommendations include fixed-wing airplanes powered by turbojet or turbofan engines or by propellers. The recommended field-measurement procedures are consistent with assumed requirements for data processing and analysis.

A Novel Approach to Noise-Filtering Based on a Gain-Scheduling Neural Network Architecture

NASA Technical Reports Server (NTRS)

Troudet, T.; Merrill, W.

1994-01-01

A gain-scheduling neural network architecture is proposed to enhance the noise-filtering efficiency of feedforward neural networks, in terms of both nominal performance and robustness. The synergistic benefits of the proposed architecture are demonstrated and discussed in the context of the noise-filtering of signals that are typically encountered in aerospace control systems. The synthesis of such a gain-scheduled neurofiltering provides the robustness of linear filtering, while preserving the nominal performance advantage of conventional nonlinear neurofiltering. Quantitative performance and robustness evaluations are provided for the signal processing of pitch rate responses to typical pilot command inputs for a modern fighter aircraft model.

Aircraft Turbine Engine Control Research at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Garg, Sanjay

2014-01-01

This lecture will provide an overview of the aircraft turbine engine control research at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the current state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. The traditional engine control problem has been to provide a means to safely transition the engine from one steady-state operating point to another based on the pilot throttle inputs. With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects in partnership with other organizations within GRC and across NASA, other government agencies, the U.S. aerospace industry, and academia to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA programs under the Aeronautics Research Mission. The second part of the lecture provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges and the key progress to date are summarized. The technologies to be discussed include system level engine control concepts, gas path diagnostics, active component control, and distributed engine control architecture. The lecture will end with a futuristic perspective of how the various current technology developments will lead to an Intelligent and Autonomous Propulsion System requiring none to very minimum pilot interface, interfacing directly with the flight management system to determine its mode of operation, and providing personalized engine control to optimize its performance given the current condition and mission objectives.

Kalman Filter Constraint Tuning for Turbofan Engine Health Estimation

NASA Technical Reports Server (NTRS)

Simon, Dan; Simon, Donald L.

2005-01-01

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints are often neglected because they do not fit easily into the structure of the Kalman filter. Recently published work has shown a new method for incorporating state variable inequality constraints in the Kalman filter, which has been shown to generally improve the filter s estimation accuracy. However, the incorporation of inequality constraints poses some risk to the estimation accuracy as the Kalman filter is theoretically optimal. This paper proposes a way to tune the filter constraints so that the state estimates follow the unconstrained (theoretically optimal) filter when the confidence in the unconstrained filter is high. When confidence in the unconstrained filter is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.

The effect of single engine fixed wing air transport on rate-responsive pacemakers.

PubMed

De Rotte, A A; Van Der Kemp, P

1999-09-01

Insufficient information exists about the safety of patients with accelerometer-based rate-responsive pacemakers in air transport by general aviation aircraft. The response in pacing rate of two types of accelerometer-based rate-responsive pacemakers with data logging capabilities was studied during test flights with single engine fixed wing aircraft. Results were compared with the rate-response of these pacemakers during transportation by car and were also interpreted in respect to physiological heart rate response of aircrew during flights in single engine fixed wing aircraft. In addition, a continuous accelerometer readout was recorded during a turbulent phase of flight. This recording was used for a pacemaker-simulator experiment with maximal sensitive motion-sensor settings. Only a minor increase in pacing rate due to aircraft motion could be demonstrated during all phases of flight at all altitudes with the pacemakers programmed in the normal mode. This increase was of the same magnitude as induced during transport by car and would be of negligible influence on the performance of the individual pacemaker patient equipped with such a pacemaker. Moreover, simultaneous Holter monitoring of the pilots during these flights showed a similar rate-response in natural heart rate compared with the increase in pacing rate induced by aircraft motion in accelerometer-based rate-responsive pacemakers. No sensor-mediated pacemaker tachycardia was seen during any of these recordings. However, a 15% increase in pacing rate was induced by severe air turbulence. Programming the maximal sensitivity of the motion sensor into the pacemaker could, on the other hand, induce a significant increase in pacing rate as was demonstrated by the simulation experiments. These results seem to rule out potentially dangerous or adverse effects from motional or vibrational influences during transport in single engine fixed wing aircraft on accelerometer-based rate-responsive pacemakers with normal activity sensor settings.

40 CFR 87.10 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., manufactured on or after January 1, 1974, and to all in-use aircraft gas turbine engines of classes T3, T8, TSS... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 87.10 Applicability. (a) The provisions of this subpart are applicable to all new...

40 CFR 87.10 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., manufactured on or after January 1, 1974, and to all in-use aircraft gas turbine engines of classes T3, T8, TSS... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 87.10 Applicability. (a) The provisions of this subpart are applicable to all new...

40 CFR 87.10 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., manufactured on or after January 1, 1974, and to all in-use aircraft gas turbine engines of classes T3, T8, TSS... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 87.10 Applicability. (a) The provisions of this subpart are applicable to all new...

40 CFR 87.10 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., manufactured on or after January 1, 1974, and to all in-use aircraft gas turbine engines of classes T3, T8, TSS... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 87.10 Applicability. (a) The provisions of this subpart are applicable to all new...

76 FR 82110 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-30

... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation...) for Thielert Aircraft Engines GmbH models TAE 125-02-99 and TAE 125-01 reciprocating engines. That AD... flight hours to within 600 flight hours for TAE 125-01 reciprocating engines. This AD was prompted by the...

The role of nonlinear effects in the propagation of noise from high-power jet aircraft.

PubMed

Gee, Kent L; Sparrow, Victor W; James, Michael M; Downing, J Micah; Hobbs, Christopher M; Gabrielson, Thomas B; Atchley, Anthony A

2008-06-01

To address the question of the role of nonlinear effects in the propagation of noise radiated by high-power jet aircraft, extensive measurements were made of the F-22A Raptor during static engine run-ups. Data were acquired at low-, intermediate-, and high-thrust engine settings with microphones located 23-305 m from the aircraft along several angles. Comparisons between the results of a generalized-Burgers-equation-based nonlinear propagation model and the measurements yield favorable agreement, whereas application of a linear propagation model results in spectral predictions that are much too low at high frequencies. The results and analysis show that significant nonlinear propagation effects occur for even intermediate-thrust engine conditions and at angles well away from the peak radiation angle. This suggests that these effects are likely to be common in the propagation of noise radiated by high-power aircraft.

14 CFR 33.73 - Power or thrust response.

Code of Federal Regulations, 2010 CFR

2010-01-01

....73 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.73 Power or... aircraft, without overtemperature, surge, stall, or other detrimental factors occurring to the engine...

14 CFR 33.73 - Power or thrust response.

Code of Federal Regulations, 2011 CFR

2011-01-01

....73 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.73 Power or... aircraft, without overtemperature, surge, stall, or other detrimental factors occurring to the engine...

A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation Strategies

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan W.; Jones, Scott M.

2017-01-01

Aircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a potential safety hazard. The aviation community is conducting research to understand this phenomena, and to identify avoidance and mitigation strategies to address the concern. To support this research, a dynamic turbofan engine model has been created to enable the development and evaluation of engine icing detection and control-based mitigation strategies. This model captures the dynamic engine response due to high ice water ingestion and the buildup of ice blockage in the engines low pressure compressor. It includes a fuel control system allowing engine closed-loop control effects during engine icing events to be emulated. The model also includes bleed air valve and horsepower extraction actuators that, when modulated, change overall engine operating performance. This system-level model has been developed and compared against test data acquired from an aircraft turbofan engine undergoing engine icing studies in an altitude test facility and also against outputs from the manufacturers customer deck. This paper will describe the model and show results of its dynamic response under open-loop and closed-loop control operating scenarios in the presence of ice blockage buildup compared against engine test cell data. Planned follow-on use of the model for the development and evaluation of icing detection and control-based mitigation strategies will also be discussed. The intent is to combine the model and control mitigation logic with an engine icing risk calculation tool capable of predicting the risk of engine icing based on current operating conditions. Upon detection of an operating region of risk for engine icing events, the control mitigation logic will seek to change the engines operating point to a region of lower risk through the modulation of available control actuators while maintaining the desired engine thrust output. Follow-on work will assess the feasibility and effectiveness of such control-based mitigation strategies.

Sensor Needs for Control and Health Management of Intelligent Aircraft Engines

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Gang, Sanjay; Hunter, Gary W.; Guo, Ten-Huei; Semega, Kenneth J.

2004-01-01

NASA and the U.S. Department of Defense are conducting programs which support the future vision of "intelligent" aircraft engines for enhancing the affordability, performance, operability, safety, and reliability of aircraft propulsion systems. Intelligent engines will have advanced control and health management capabilities enabling these engines to be self-diagnostic, self-prognostic, and adaptive to optimize performance based upon the current condition of the engine or the current mission of the vehicle. Sensors are a critical technology necessary to enable the intelligent engine vision as they are relied upon to accurately collect the data required for engine control and health management. This paper reviews the anticipated sensor requirements to support the future vision of intelligent engines from a control and health management perspective. Propulsion control and health management technologies are discussed in the broad areas of active component controls, propulsion health management and distributed controls. In each of these three areas individual technologies will be described, input parameters necessary for control feedback or health management will be discussed, and sensor performance specifications for measuring these parameters will be summarized.

14 CFR 33.31 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.31 Applicability. This subpart prescribes additional design and construction requirements for reciprocating aircraft engines. ...

14 CFR 33.31 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.31 Applicability. This subpart prescribes additional design and construction requirements for reciprocating aircraft engines. ...

14 CFR 33.61 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.61 Applicability. This subpart prescribes additional design and construction requirements for turbine aircraft engines. ...

14 CFR 33.61 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.61 Applicability. This subpart prescribes additional design and construction requirements for turbine aircraft engines. ...

14 CFR 33.61 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.61 Applicability. This subpart prescribes additional design and construction requirements for turbine aircraft engines. ...

14 CFR 21.33 - Inspection and tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

...— (1) No aircraft, aircraft engine, propeller, or part thereof may be presented to the FAA for test..., aircraft engine, propeller, or part thereof; and (2) No change may be made to an aircraft, aircraft engine, propeller, or part thereof between the time that compliance with paragraphs (b)(2) through (b)(4) of this...

14 CFR 21.33 - Inspection and tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

...— (1) No aircraft, aircraft engine, propeller, or part thereof may be presented to the FAA for test..., aircraft engine, propeller, or part thereof; and (2) No change may be made to an aircraft, aircraft engine, propeller, or part thereof between the time that compliance with paragraphs (b)(2) through (b)(4) of this...

14 CFR 21.33 - Inspection and tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

...— (1) No aircraft, aircraft engine, propeller, or part thereof may be presented to the FAA for test..., aircraft engine, propeller, or part thereof; and (2) No change may be made to an aircraft, aircraft engine, propeller, or part thereof between the time that compliance with paragraphs (b)(2) through (b)(4) of this...

78 FR 1728 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... scheduled maintenance, whichever occurs first, do the following. (1) Remove the oil filler plug and check... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation... all Thielert Aircraft Engines GmbH (TAE) TAE 125-02-99 and TAE 125-02-114 reciprocating engines. This...

Study of small turbofan engines applicable to general-aviation aircraft

NASA Technical Reports Server (NTRS)

Merrill, G. L.; Burnett, G. A.; Alsworth, C. C.

1973-01-01

The applicability of small turbofan engines to general aviation aircraft is discussed. The engine and engine/airplane performance, weight, size, and cost interrelationships are examined. The effects of specific engine noise constraints are evaluated. The factors inhibiting the use of turbofan engines in general aviation aircraft are identified.

78 FR 1733 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation... (AD) for all Thielert Aircraft Engines GmbH models TAE 125-01, TAE 125-02- 99, and TAE 125-02-114 reciprocating engines. That AD currently requires installation of full-authority digital electronic control...

14 CFR 21.128 - Tests: aircraft engines.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Tests: aircraft engines. 21.128 Section 21... engines. (a) Each person manufacturing aircraft engines under a type certificate must subject each engine (except rocket engines for which the manufacturer must establish a sampling technique) to an acceptable...

Study of the use of a nonlinear, rate limited, filter on pilot control signals

NASA Technical Reports Server (NTRS)

Adams, J. J.

1977-01-01

The use of a filter on the pilot's control output could improve the performance of the pilot-aircraft system. What is needed is a filter with a sharp high frequency cut-off, no resonance peak, and a minimum of lag at low frequencies. The present investigation studies the usefulness of a nonlinear, rate limited, filter in performing the needed function. The nonlinear filter is compared with a linear, first order filter, and no filter. An analytical study using pilot models and a simulation study using experienced test pilots was performed. The results showed that the nonlinear filter does promote quick, steady maneuvering. It is shown that the nonlinear filter attenuates the high frequency remnant and adds less phase lag to the low frequency signal than does the linear filter. It is also shown that the rate limit in the nonlinear filter can be set to be too restrictive, causing an unstable pilot-aircraft system response.

14 CFR 34.61 - Turbine fuel specifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be present. Specification for Fuel To Be Used in Aircraft Turbine Engine Emission Testing Property... 34.61 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.61 Turbine fuel...

14 CFR 34.61 - Turbine fuel specifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.61 Turbine fuel... be present. Specification for Fuel To Be Used in Aircraft Turbine Engine Emission Testing Property... 34.61 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT...

14 CFR 34.61 - Turbine fuel specifications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.61 Turbine fuel... be present. Specification for Fuel To Be Used in Aircraft Turbine Engine Emission Testing Property... 34.61 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT...

Final Rule for Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

EPA Pesticide Factsheets

EPA adopted emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

Methods Developed by the Tools for Engine Diagnostics Task to Monitor and Predict Rotor Damage in Real Time

NASA Technical Reports Server (NTRS)

Baaklini, George Y.; Smith, Kevin; Raulerson, David; Gyekenyesi, Andrew L.; Sawicki, Jerzy T.; Brasche, Lisa

2003-01-01

Tools for Engine Diagnostics is a major task in the Propulsion System Health Management area of the Single Aircraft Accident Prevention project under NASA s Aviation Safety Program. The major goal of the Aviation Safety Program is to reduce fatal aircraft accidents by 80 percent within 10 years and by 90 percent within 25 years. The goal of the Propulsion System Health Management area is to eliminate propulsion system malfunctions as a primary or contributing factor to the cause of aircraft accidents. The purpose of Tools for Engine Diagnostics, a 2-yr-old task, is to establish and improve tools for engine diagnostics and prognostics that measure the deformation and damage of rotating engine components at the ground level and that perform intermittent or continuous monitoring on the engine wing. In this work, nondestructive-evaluation- (NDE-) based technology is combined with model-dependent disk spin experimental simulation systems, like finite element modeling (FEM) and modal norms, to monitor and predict rotor damage in real time. Fracture mechanics time-dependent fatigue crack growth and damage-mechanics-based life estimation are being developed, and their potential use investigated. In addition, wireless eddy current and advanced acoustics are being developed for on-wing and just-in-time NDE engine inspection to provide deeper access and higher sensitivity to extend on-wing capabilities and improve inspection readiness. In the long run, these methods could establish a base for prognostic sensing while an engine is running, without any overt actions, like inspections. This damage-detection strategy includes experimentally acquired vibration-, eddy-current- and capacitance-based displacement measurements and analytically computed FEM-, modal norms-, and conventional rotordynamics-based models of well-defined damages and critical mass imbalances in rotating disks and rotors.

Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

2012-01-01

The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

Theseus in Flight

NASA Technical Reports Server (NTRS)

1996-01-01

The twin pusher propeller-driven engines of the Theseus research aircraft can be clearly seen in this photo, taken during a 1996 research flight at NASA's Dryden Flight Research Center, Edwards, California. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

75 FR 53846 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Models TAE 125-01 and TAE 125-02...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-02

... Engines Installed In, But Not Limited To, Diamond Aircraft Industries Model DA 42 Airplanes; Correction..., Diamond Aircraft Industries model DA 42 airplanes. The part number for engine model TAE 125-01 is missing...-99 reciprocating engines, installed in, but not limited to, Diamond Aircraft Industries model DA 42...

Proposed Rule and Related Materials for Control of Emissions of Air Pollution From Nonroad Diesel Engines Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures

EPA Pesticide Factsheets

EPA is proposing to adopt emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

NASA Technical Reports Server (NTRS)

Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elkoby, Ronen (Inventor)

2014-01-01

The aircraft exhaust engine nozzle system includes a fan nozzle to receive a fan flow from a fan disposed adjacent to an engine disposed above an airframe surface of the aircraft, a core nozzle disposed within the fan nozzle and receiving an engine core flow, and a pylon structure connected to the core nozzle and structurally attached with the airframe surface to secure the engine to the aircraft.

Interactive, Secure Web-enabled Aircraft Engine Simulation Using XML Databinding Integration

NASA Technical Reports Server (NTRS)

Lin, Risheng; Afjeh, Abdollah A.

2003-01-01

This paper discusses the detailed design of an XML databinding framework for aircraft engine simulation. The framework provides an object interface to access and use engine data. while at the same time preserving the meaning of the original data. The Language independent representation of engine component data enables users to move around XML data using HTTP through disparate networks. The application of this framework is demonstrated via a web-based turbofan propulsion system simulation using the World Wide Web (WWW). A Java Servlet based web component architecture is used for rendering XML engine data into HTML format and dealing with input events from the user, which allows users to interact with simulation data from a web browser. The simulation data can also be saved to a local disk for archiving or to restart the simulation at a later time.

77 FR 39623 - Airworthiness Standards: Aircraft Engines; Technical Amendment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

...] Airworthiness Standards: Aircraft Engines; Technical Amendment AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; technical amendment. SUMMARY: This amendment clarifies aircraft engine... from applicants requesting FAA engine type certifications and aftermarket certifications, such as...

14 CFR 33.63 - Vibration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.63 Vibration. Each engine... range of rotational speeds and power/thrust, without inducing excessive stress in any engine part...

14 CFR 33.63 - Vibration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.63 Vibration. Each engine... range of rotational speeds and power/thrust, without inducing excessive stress in any engine part...

Knowledge-Acquisition Tool For Expert System

NASA Technical Reports Server (NTRS)

Disbrow, James D.; Duke, Eugene L.; Regenie, Victoria A.

1988-01-01

Digital flight-control systems monitored by computer program that evaluates and recommends. Flight-systems engineers for advanced, high-performance aircraft use knowlege-acquisition tool for expert-system flight-status monitor suppling interpretative data. Interpretative function especially important in time-critical, high-stress situations because it facilitates problem identification and corrective strategy. Conditions evaluated and recommendations made by ground-based engineers having essential knowledge for analysis and monitoring of performances of advanced aircraft systems.

14 CFR 33.78 - Rain and hail ingestion.

Code of Federal Regulations, 2010 CFR

2010-01-01

....78 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.78 Rain and... aircraft operating in rough air, with the engine at maximum continuous power, may not cause unacceptable...

76 FR 68636 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines AGENCY: Federal Aviation... airworthiness directive (AD) for Thielert Aircraft Engines GmbH (TAE) Models TAE 125-01 and TAE 125- 02-99 reciprocating engines. That AD currently requires replacement of certain part numbers (P/Ns) and serial numbers...

Analysis of a topping-cycle, aircraft, gas-turbine-engine system which uses cryogenic fuel

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1984-01-01

A topping-cycle aircraft engine system which uses a cryogenic fuel was investigated. This system consists of a main turboshaft engine that is mechanically coupled (by cross-shafting) to a topping loop, which augments the shaft power output of the system. The thermodynamic performance of the topping-cycle engine was analyzed and compared with that of a reference (conventional) turboshaft engine. For the cycle operating conditions selected, the performance of the topping-cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping-cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping-cycle engine is comparable with that of the reference turboshaft engine.

Study of LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

Q-FANSTM for general aviation aircraft

NASA Technical Reports Server (NTRS)

Worobel, R.; Mayo, M. G.

1973-01-01

Continued growth of general aviation over the next 10 to 15 years is dependent on continuing improvement in aircraft safety, utility, performance and cost. Moreover, these advanced aircraft will need to conform to expected government regulations controlling propulsion system emissions and noise levels. An attractive compact low noise propulsor concept, the Q-FANTM when matched to piston, rotary combustion, or gas turbine engines opens up the exciting prospect of new, cleaner airframe designs for the next generation of general aviation aircraft which will provide these improvements and meet the expected noise and pollution restriction of the 1980 time period. New Q-FAN methodology which was derived to predict Q-FAN noise, weight and cost is presented. Based on this methodology Q-FAN propulsion system performance, weight, noise, and cost trends are discussed. Then the impact of this propulsion system type on the complete aircraft is investigated for several representative aircraft size categories. Finally, example conceptual designs for Q-FAN/engine integration and aircraft installations are presented.

40 CFR 87.89 - Compliance with smoke emission standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.89 Compliance with smoke emission standards... engine of the model being tested. An acceptable alternative to testing every engine is described in...

40 CFR 87.89 - Compliance with smoke emission standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.89 Compliance with smoke emission standards... engine of the model being tested. An acceptable alternative to testing every engine is described in...

14 CFR 33.70 - Engine life-limited parts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine life-limited parts. 33.70 Section 33.70 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.70 Engine life...

14 CFR 33.70 - Engine life-limited parts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine life-limited parts. 33.70 Section 33.70 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.70 Engine life...

14 CFR 121.363 - Responsibility for airworthiness.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) The airworthiness of its aircraft, including airframes, aircraft engines, propellers, appliances, and... aircraft, including airframes, aircraft engines, propellers, appliances, emergency equipment, and parts...

14 CFR 121.363 - Responsibility for airworthiness.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) The airworthiness of its aircraft, including airframes, aircraft engines, propellers, appliances, and... aircraft, including airframes, aircraft engines, propellers, appliances, emergency equipment, and parts...

14 CFR 121.363 - Responsibility for airworthiness.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) The airworthiness of its aircraft, including airframes, aircraft engines, propellers, appliances, and... aircraft, including airframes, aircraft engines, propellers, appliances, emergency equipment, and parts...

14 CFR 121.363 - Responsibility for airworthiness.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) The airworthiness of its aircraft, including airframes, aircraft engines, propellers, appliances, and... aircraft, including airframes, aircraft engines, propellers, appliances, emergency equipment, and parts...

14 CFR 121.363 - Responsibility for airworthiness.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) The airworthiness of its aircraft, including airframes, aircraft engines, propellers, appliances, and... aircraft, including airframes, aircraft engines, propellers, appliances, emergency equipment, and parts...

Proceedings of the Annual Tri-Service Meeting for Aircraft Engine Monitoring and Diagnostics (7th) Held on 5-7 December 1978, at Arnold Engineering Development Center, Arnold AFS, Tennessee

DTIC Science & Technology

1979-07-01

Annual Tri-Service meeting on Aircraft Engine Monitoring and Diagnostics held last fall. 2. For all turbojet and turbofan engines , low cycle fatigue...7 December 1978. Each presentation contains an over-, view of the results and conclusions of the aircraft turbine engine diagnostic efforts that have... AIRCRAFT ENGINE 2-41 MONITORING AND DIAGNOSTIC MEETING T-38 EHMS UPDATE 2-43 A-10 TURBINE ENGINE EVALUATION (TEMS) 2-47 USAF TERMINOLOGY FOR SCORING

Quiet engine program flight engine design study

NASA Technical Reports Server (NTRS)

Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

1974-01-01

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

Aircraft gas turbine materials and processes.

PubMed

Kear, B H; Thompson, E R

1980-05-23

Materials and processing innovations that have been incorporated into the manufacture of critical components for high-performance aircraft gas turbine engines are described. The materials of interest are the nickel- and cobalt-base superalloys for turbine and burner sections of the engine, and titanium alloys and composites for compressor and fan sections of the engine. Advanced processing methods considered include directional solidification, hot isostatic pressing, superplastic foring, directional recrystallization, and diffusion brazing. Future trends in gas turbine technology are discussed in terms of materials availability, substitution, and further advances in air-cooled hardware.

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

14 CFR 34.5 - Special test procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES General Provisions § 34.5 Special test... or operator of aircraft or aircraft engines, approve test procedures for any aircraft or aircraft engine that is not susceptible to satisfactory testing by the procedures set forth herein. Prior to...

A NASA study of the impact of technology on future carrier based tactical aircraft - Overview

NASA Technical Reports Server (NTRS)

Wilson, S. B., III

1992-01-01

This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.

Resilient Propulsion Control Research for the NASA Integrated Resilient Aircraft Control (IRAC) Project

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei; Litt, Jonathan S.

2007-01-01

Gas turbine engines are designed to provide sufficient safety margins to guarantee robust operation with an exceptionally long life. However, engine performance requirements may be drastically altered during abnormal flight conditions or emergency maneuvers. In some situations, the conservative design of the engine control system may not be in the best interest of overall aircraft safety; it may be advantageous to "sacrifice" the engine to "save" the aircraft. Motivated by this opportunity, the NASA Aviation Safety Program is conducting resilient propulsion research aimed at developing adaptive engine control methodologies to operate the engine beyond the normal domain for emergency operations to maximize the possibility of safely landing the damaged aircraft. Previous research studies and field incident reports show that the propulsion system can be an effective tool to help control and eventually land a damaged aircraft. Building upon the flight-proven Propulsion Controlled Aircraft (PCA) experience, this area of research will focus on how engine control systems can improve aircraft safe-landing probabilities under adverse conditions. This paper describes the proposed research topics in Engine System Requirements, Engine Modeling and Simulation, Engine Enhancement Research, Operational Risk Analysis and Modeling, and Integrated Flight and Propulsion Controller Designs that support the overall goal.

Aircraft Flight Modeling During the Optimization of Gas Turbine Engine Working Process

NASA Astrophysics Data System (ADS)

Tkachenko, A. Yu; Kuz'michev, V. S.; Krupenich, I. N.

2018-01-01

The article describes a method for simulating the flight of the aircraft along a predetermined path, establishing a functional connection between the parameters of the working process of gas turbine engine and the efficiency criteria of the aircraft. This connection is necessary for solving the optimization tasks of the conceptual design stage of the engine according to the systems approach. Engine thrust level, in turn, influences the operation of aircraft, thus making accurate simulation of the aircraft behavior during flight necessary for obtaining the correct solution. The described mathematical model of aircraft flight provides the functional connection between the airframe characteristics, working process of gas turbine engines (propulsion system), ambient and flight conditions and flight profile features. This model provides accurate results of flight simulation and the resulting aircraft efficiency criteria, required for optimization of working process and control function of a gas turbine engine.

A Model-Based Anomaly Detection Approach for Analyzing Streaming Aircraft Engine Measurement Data

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan W.

2014-01-01

This paper presents a model-based anomaly detection architecture designed for analyzing streaming transient aircraft engine measurement data. The technique calculates and monitors residuals between sensed engine outputs and model predicted outputs for anomaly detection purposes. Pivotal to the performance of this technique is the ability to construct a model that accurately reflects the nominal operating performance of the engine. The dynamic model applied in the architecture is a piecewise linear design comprising steady-state trim points and dynamic state space matrices. A simple curve-fitting technique for updating the model trim point information based on steadystate information extracted from available nominal engine measurement data is presented. Results from the application of the model-based approach for processing actual engine test data are shown. These include both nominal fault-free test case data and seeded fault test case data. The results indicate that the updates applied to improve the model trim point information also improve anomaly detection performance. Recommendations for follow-on enhancements to the technique are also presented and discussed.

A Model-Based Anomaly Detection Approach for Analyzing Streaming Aircraft Engine Measurement Data

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan Walker

2015-01-01

This paper presents a model-based anomaly detection architecture designed for analyzing streaming transient aircraft engine measurement data. The technique calculates and monitors residuals between sensed engine outputs and model predicted outputs for anomaly detection purposes. Pivotal to the performance of this technique is the ability to construct a model that accurately reflects the nominal operating performance of the engine. The dynamic model applied in the architecture is a piecewise linear design comprising steady-state trim points and dynamic state space matrices. A simple curve-fitting technique for updating the model trim point information based on steadystate information extracted from available nominal engine measurement data is presented. Results from the application of the model-based approach for processing actual engine test data are shown. These include both nominal fault-free test case data and seeded fault test case data. The results indicate that the updates applied to improve the model trim point information also improve anomaly detection performance. Recommendations for follow-on enhancements to the technique are also presented and discussed.

14 CFR 33.53 - Engine system and component tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine system and component tests. 33.53 Section 33.53 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.53 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

78 FR 63015 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation Administration (FAA... regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7... standards for certain turbine engine powered airplanes to incorporate the standards promulgated by the...

[Psychophysiological aspects of naval aviation pilots of the Navy in the operation of highly carrier-based aircraft].

PubMed

Mel'nik, S G; Chulaevskiĭ, A O

2011-08-01

The authors have shown that the most difficult elements of the flight deck of the ship are springboard takeoff and aerofinishing landing. An important task is to study the aerodynamic characteristics of the behavior of the aircraft during takeoff different characteristics, forming crews ready to act in particular situations. Adverse factors are the operating conditions of habitability of aircraft (noise, vibration, fumes in the air at work, and aircraft engines, etc.) that have a significant impact on the life of air crew and engineering staff. It is concluded that the development and use of effective means of protecting the organism from the effect of these factors is a priority for specialists in aviation medicine.

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR... turboprop engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

40 CFR 87.61 - Turbine fuel specifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.61 Turbine fuel specifications. For... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Turbine fuel specifications. 87.61...

40 CFR 87.61 - Turbine fuel specifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.61 Turbine fuel specifications. For... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Turbine fuel specifications. 87.61...

14 CFR 49.1 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-01-01

... absorb 750 or more rated takeoff shaft horsepower; and (4) Any aircraft engine, propeller, or appliance... aircraft, aircraft engine, or propeller, or any spare part, maintained at a designated location or... 49 U.S.C. 44101-44104; (2) Any specifically identified aircraft engine of 750 or more rated takeoff...

14 CFR 49.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... absorb 750 or more rated takeoff shaft horsepower; and (4) Any aircraft engine, propeller, or appliance... aircraft, aircraft engine, or propeller, or any spare part, maintained at a designated location or... 49 U.S.C. 44101-44104; (2) Any specifically identified aircraft engine of 750 or more rated takeoff...

14 CFR 49.1 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... absorb 750 or more rated takeoff shaft horsepower; and (4) Any aircraft engine, propeller, or appliance... aircraft, aircraft engine, or propeller, or any spare part, maintained at a designated location or... 49 U.S.C. 44101-44104; (2) Any specifically identified aircraft engine of 750 or more rated takeoff...

14 CFR 49.1 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... absorb 750 or more rated takeoff shaft horsepower; and (4) Any aircraft engine, propeller, or appliance... aircraft, aircraft engine, or propeller, or any spare part, maintained at a designated location or... 49 U.S.C. 44101-44104; (2) Any specifically identified aircraft engine of 750 or more rated takeoff...

14 CFR 49.1 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-01-01

... absorb 750 or more rated takeoff shaft horsepower; and (4) Any aircraft engine, propeller, or appliance... aircraft, aircraft engine, or propeller, or any spare part, maintained at a designated location or... 49 U.S.C. 44101-44104; (2) Any specifically identified aircraft engine of 750 or more rated takeoff...

Systematic Biological Filter Design with a Desired I/O Filtering Response Based on Promoter-RBS Libraries.

PubMed

Hsu, Chih-Yuan; Pan, Zhen-Ming; Hu, Rei-Hsing; Chang, Chih-Chun; Cheng, Hsiao-Chun; Lin, Che; Chen, Bor-Sen

2015-01-01

In this study, robust biological filters with an external control to match a desired input/output (I/O) filtering response are engineered based on the well-characterized promoter-RBS libraries and a cascade gene circuit topology. In the field of synthetic biology, the biological filter system serves as a powerful detector or sensor to sense different molecular signals and produces a specific output response only if the concentration of the input molecular signal is higher or lower than a specified threshold. The proposed systematic design method of robust biological filters is summarized into three steps. Firstly, several well-characterized promoter-RBS libraries are established for biological filter design by identifying and collecting the quantitative and qualitative characteristics of their promoter-RBS components via nonlinear parameter estimation method. Then, the topology of synthetic biological filter is decomposed into three cascade gene regulatory modules, and an appropriate promoter-RBS library is selected for each module to achieve the desired I/O specification of a biological filter. Finally, based on the proposed systematic method, a robust externally tunable biological filter is engineered by searching the promoter-RBS component libraries and a control inducer concentration library to achieve the optimal reference match for the specified I/O filtering response.

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

PubMed Central

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-01-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect. PMID:28252034

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

NASA Astrophysics Data System (ADS)

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-03-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect.

Mechanistic failure mode investigation and resolution of parvovirus retentive filters.

PubMed

LaCasse, Daniel; Lute, Scott; Fiadeiro, Marcus; Basha, Jonida; Stork, Matthew; Brorson, Kurt; Godavarti, Ranga; Gallo, Chris

2016-07-08

Virus retentive filters are a key product safety measure for biopharmaceuticals. A simplistic perception is that they function solely based on a size-based particle removal mechanism of mechanical sieving and retention of particles based on their hydrodynamic size. Recent observations have revealed a more nuanced picture, indicating that changes in viral particle retention can result from process pressure and/or flow interruptions. In this study, a mechanistic investigation was performed to help identify a potential mechanism leading to the reported reduced particle retention in small virus filters. Permeate flow rate or permeate driving force were varied and analyzed for their impact on particle retention in three commercially available small virus retentive filters. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:959-970, 2016. © 2016 American Institute of Chemical Engineers.

Structures, performance, benefit, cost study. [gas turbine engines

NASA Technical Reports Server (NTRS)

Feder, E.

1981-01-01

Aircraft engine structures were studied to identify the advanced structural technologies that would provide the most benefits to future aircraft operations. A series of studies identified engine systems with the greatest potential for improvements. Based on these studies, six advanced generic structural concepts were selected and conceptually designed. The benefits of each concept were quantitatively assessed in terms of thrust specific fuel consumption, weight, cost, maintenance cost, fuel burned and direct operating cost plus interest. The probability of success of each concept was also determined. The concepts were ranked and the three most promising were selected for further study which consisted of identifying and comprehensively outlining the advanced technologies required to develop these concepts for aircraft engine application. Analytic, fabrication, and test technology developments are required. The technology programs outlined emphasize the need to provide basic, fundamental understanding of technology to obtain the benefit goals.

Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment.

PubMed

Lee, Ben H; Santoni, Gregory W; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Zahniser, Mark S; Wofsy, Steven C; Munger, J William

2011-09-15

The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

NASA Technical Reports Server (NTRS)

Bansal, Indar

1993-01-01

The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

Sliding Mode Fault Tolerant Control with Adaptive Diagnosis for Aircraft Engines

NASA Astrophysics Data System (ADS)

Xiao, Lingfei; Du, Yanbin; Hu, Jixiang; Jiang, Bin

2018-03-01

In this paper, a novel sliding mode fault tolerant control method is presented for aircraft engine systems with uncertainties and disturbances on the basis of adaptive diagnostic observer. By taking both sensors faults and actuators faults into account, the general model of aircraft engine control systems which is subjected to uncertainties and disturbances, is considered. Then, the corresponding augmented dynamic model is established in order to facilitate the fault diagnosis and fault tolerant controller design. Next, a suitable detection observer is designed to detect the faults effectively. Through creating an adaptive diagnostic observer and based on sliding mode strategy, the sliding mode fault tolerant controller is constructed. Robust stabilization is discussed and the closed-loop system can be stabilized robustly. It is also proven that the adaptive diagnostic observer output errors and the estimations of faults converge to a set exponentially, and the converge rate greater than some value which can be adjusted by choosing designable parameters properly. The simulation on a twin-shaft aircraft engine verifies the applicability of the proposed fault tolerant control method.

Theseus in Flight

NASA Technical Reports Server (NTRS)

1996-01-01

The Theseus research aircraft in flight over Rogers Dry Lake, Edwards, California, during a 1996 research flight. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

Theseus Assembly Sequence #1

NASA Technical Reports Server (NTRS)

1996-01-01

The Theseus prototype research aircraft being assembled at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

Theseus Assembly Sequence #3

NASA Technical Reports Server (NTRS)

1996-01-01

The Theseus prototype research aircraft being assembled at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

A nonlinear Kalman filtering approach to embedded control of turbocharged diesel engines

NASA Astrophysics Data System (ADS)

Rigatos, Gerasimos; Siano, Pierluigi; Arsie, Ivan

2014-10-01

The development of efficient embedded control for turbocharged Diesel engines, requires the programming of elaborated nonlinear control and filtering methods. To this end, in this paper nonlinear control for turbocharged Diesel engines is developed with the use of Differential flatness theory and the Derivative-free nonlinear Kalman Filter. It is shown that the dynamic model of the turbocharged Diesel engine is differentially flat and admits dynamic feedback linearization. It is also shown that the dynamic model can be written in the linear Brunovsky canonical form for which a state feedback controller can be easily designed. To compensate for modeling errors and external disturbances the Derivative-free nonlinear Kalman Filter is used and redesigned as a disturbance observer. The filter consists of the Kalman Filter recursion on the linearized equivalent of the Diesel engine model and of an inverse transformation based on differential flatness theory which enables to obtain estimates for the state variables of the initial nonlinear model. Once the disturbances variables are identified it is possible to compensate them by including an additional control term in the feedback loop. The efficiency of the proposed control method is tested through simulation experiments.

Technology for reducing aircraft engine pollution

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Kempke, E. E., Jr.

1975-01-01

Programs have been initiated by NASA to develop and demonstrate advanced technology for reducing aircraft gas turbine and piston engine pollutant emissions. These programs encompass engines currently in use for a wide variety of aircraft from widebody-jets to general aviation. Emission goals for these programs are consistent with the established EPA standards. Full-scale engine demonstrations of the most promising pollutant reduction techniques are planned within the next three years. Preliminary tests of advanced technology gas turbine engine combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft engines without adverse effects on fuel consumption. Fundamental-type programs are yielding results which indicate that future generation gas turbine aircraft engines may be able to utilize extremely low pollutant emission combustion systems.

Aircraft Flight Envelope Determination using Upset Detection and Physical Modeling Methods

NASA Technical Reports Server (NTRS)

Keller, Jeffrey D.; McKillip, Robert M. Jr.; Kim, Singwan

2009-01-01

The development of flight control systems to enhance aircraft safety during periods of vehicle impairment or degraded operations has been the focus of extensive work in recent years. Conditions adversely affecting aircraft flight operations and safety may result from a number of causes, including environmental disturbances, degraded flight operations, and aerodynamic upsets. To enhance the effectiveness of adaptive and envelope limiting controls systems, it is desirable to examine methods for identifying the occurrence of anomalous conditions and for assessing the impact of these conditions on the aircraft operational limits. This paper describes initial work performed toward this end, examining the use of fault detection methods applied to the aircraft for aerodynamic performance degradation identification and model-based methods for envelope prediction. Results are presented in which a model-based fault detection filter is applied to the identification of aircraft control surface and stall departure failures/upsets. This application is supported by a distributed loading aerodynamics formulation for the flight dynamics system reference model. Extensions for estimating the flight envelope due to generalized aerodynamic performance degradation are also described.

Bell XP–59A Airacomet in the Altitude Wind Tunnel

NASA Image and Video Library

1944-03-21

The secret test of the Bell YP–59A Airacomet in the spring of 1944 was the first investigation in the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory’s new Altitude Wind Tunnel (AWT). The Airacomet, powered by two General Electric I–A centrifugal turbojets, was the first US jet aircraft. The Airacomet’s 290-miles per hour speed, however, was dwarfed by the German Messerschmitt Me-262 Schwalbe’s 540 miles per hour. In 1941 and 1942 General Electric built the first US jet engines based on technical drawings from British engineer Frank Whittle. Bell Aircraft was contracted to produce an airframe to incorporate the new engines. The result was the Bell XP–59A Airacomet. The aircraft made its first flight over Muroc Lake, California, on October 2, 1942. The aircraft continued to struggle over the next year and the NACA was asked to test it in the new AWT. A Bell YP–59A was flown from the Bell plant in Buffalo to Cleveland by Bob Stanley, who had piloted the first successful flight of the XP–59A at Muroc in 1942. The wing tips and tail were cut from the aircraft so that it would fit into the AWT’s test section. The study first analyzed the engines in their original configuration and then implemented a boundary layer removal duct, a new nacelle inlet, and new cooling seals. Tests of the modified version showed that the improved airflow distribution increased the I–16’s performance by 25 percent. Despite the improved speed, the aircraft was not stable enough to be used in combat, and the design was soon abandoned.

14 CFR 34.60 - Introduction.

Code of Federal Regulations, 2012 CFR

2012-01-01

... EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.60 Introduction. (a) Except as provided... determine the conformity of new aircraft gas turbine engines with the applicable standards set forth in this...

14 CFR 33.70 - Engine life-limited parts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... parts are rotor and major static structural parts whose primary failure is likely to result in a....70 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.70 Engine life...

14 CFR 34.62 - Test procedure (propulsion engines).

Code of Federal Regulations, 2011 CFR

2011-01-01

... Section 34.62 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.62 Test procedure...

14 CFR 33.66 - Bleed air system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.66 Bleed air system. The engine must supply bleed air without adverse effect on the engine, excluding reduced thrust or power...

14 CFR 33.74 - Continued rotation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.74 Continued rotation. If any of the engine main rotating systems continue to rotate after the engine is shutdown for any reason...

14 CFR 33.67 - Fuel system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.67 Fuel system. (a) With fuel supplied to the engine at the flow and pressure specified by the applicant, the engine must...

14 CFR 33.66 - Bleed air system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.66 Bleed air system. The engine must supply bleed air without adverse effect on the engine, excluding reduced thrust or power...

14 CFR 33.74 - Continued rotation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.74 Continued rotation. If any of the engine main rotating systems continue to rotate after the engine is shutdown for any reason...

14 CFR 34.62 - Test procedure (propulsion engines).

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 34.62 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.62 Test procedure...

14 CFR 33.67 - Fuel system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.67 Fuel system. (a) With fuel supplied to the engine at the flow and pressure specified by the applicant, the engine must...

14 CFR 33.69 - Ignitions system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.69 Ignitions system. Each engine must be equipped with an ignition system for starting the engine on the ground and in flight. An...

14 CFR 33.69 - Ignitions system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.69 Ignitions system. Each engine must be equipped with an ignition system for starting the engine on the ground and in flight. An...

40 CFR 87.81 - Fuel specifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.81 Fuel specifications. Fuel having specifications as provided in § 87...

40 CFR 87.81 - Fuel specifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.81 Fuel specifications. Fuel having specifications as provided in § 87...

14 CFR 34.71 - Compliance with gaseous emission standards.

Code of Federal Regulations, 2012 CFR

2012-01-01

... TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.71...

Flexible manufacturing of aircraft engine parts

NASA Astrophysics Data System (ADS)

Hassan, Ossama M.; Jenkins, Douglas M.

1992-06-01

GE Aircraft Engines, a major supplier of jet engines for commercial and military aircraft, has developed a fully integrated manufacturing facility to produce aircraft engine components in flexible manufacturing cells. This paper discusses many aspects of the implementation including process technologies, material handling, software control system architecture, socio-technical systems and lessons learned. Emphasis is placed on the appropriate use of automation in a flexible manufacturing system.

14 CFR 135.421 - Additional maintenance requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... programs, or a program approved by the Administrator, for each aircraft engine, propeller, rotor, and each... instructions set forth by the manufacturer as required by this chapter for the aircraft, aircraft engine, propeller, rotor or item of emergency equipment. (c) For each single engine aircraft to be used in passenger...

14 CFR 135.421 - Additional maintenance requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... programs, or a program approved by the Administrator, for each aircraft engine, propeller, rotor, and each... instructions set forth by the manufacturer as required by this chapter for the aircraft, aircraft engine, propeller, rotor or item of emergency equipment. (c) For each single engine aircraft to be used in passenger...

14 CFR 135.421 - Additional maintenance requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... programs, or a program approved by the Administrator, for each aircraft engine, propeller, rotor, and each... instructions set forth by the manufacturer as required by this chapter for the aircraft, aircraft engine, propeller, rotor or item of emergency equipment. (c) For each single engine aircraft to be used in passenger...

14 CFR 135.421 - Additional maintenance requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... programs, or a program approved by the Administrator, for each aircraft engine, propeller, rotor, and each... instructions set forth by the manufacturer as required by this chapter for the aircraft, aircraft engine, propeller, rotor or item of emergency equipment. (c) For each single engine aircraft to be used in passenger...

14 CFR 135.421 - Additional maintenance requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... programs, or a program approved by the Administrator, for each aircraft engine, propeller, rotor, and each... instructions set forth by the manufacturer as required by this chapter for the aircraft, aircraft engine, propeller, rotor or item of emergency equipment. (c) For each single engine aircraft to be used in passenger...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES General Provisions § 34.1 Definitions... in, or which is manufactured for installation in, an aircraft. Aircraft gas turbine engine means a.... Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all aircraft...

Real-Time Radar-Based Tracking and State Estimation of Multiple Non-Conformant Aircraft

NASA Technical Reports Server (NTRS)

Cook, Brandon; Arnett, Timothy; Macmann, Owen; Kumar, Manish

2017-01-01

In this study, a novel solution for automated tracking of multiple unknown aircraft is proposed. Many current methods use transponders to self-report state information and augment track identification. While conformant aircraft typically report transponder information to alert surrounding aircraft of its state, vehicles may exist in the airspace that are non-compliant and need to be accurately tracked using alternative methods. In this study, a multi-agent tracking solution is presented that solely utilizes primary surveillance radar data to estimate aircraft state information. Main research challenges include state estimation, track management, data association, and establishing persistent track validity. In an effort to realize these challenges, techniques such as Maximum a Posteriori estimation, Kalman filtering, degree of membership data association, and Nearest Neighbor Spanning Tree clustering are implemented for this application.

Thrust Performance Evaluation of a Turbofan Engine Based on Exergetic Approach and Thrust Management in Aircraft

NASA Astrophysics Data System (ADS)

Yalcin, Enver

2017-05-01

The environmental parameters such as temperature and air pressure which are changing depending on altitudes are effective on thrust and fuel consumption of aircraft engines. In flights with long routes, thrust management function in airplane information system has a structure that ensures altitude and performance management. This study focused on thrust changes throughout all flight were examined by taking into consideration their energy and exergy performances for fuel consumption of an aircraft engine used in flight with long route were taken as reference. The energetic and exergetic performance evaluations were made under the various altitude conditions. The thrust changes for different altitude conditions were obtained to be at 86.53 % in descending direction and at 142.58 % in ascending direction while the energy and exergy efficiency changes for the referenced engine were found to be at 80.77 % and 84.45 %, respectively. The results revealed here can be helpful to manage thrust and reduce fuel consumption, but engine performance will be in accordance with operation requirements.

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Code of Federal Regulations, 2011 CFR

2011-01-01

... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...) Ground locking: A total of 45 hours with the propeller brake engaged in a manner which clearly...

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...) Ground locking: A total of 45 hours with the propeller brake engaged in a manner which clearly...

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Code of Federal Regulations, 2012 CFR

2012-01-01

... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...) Ground locking: A total of 45 hours with the propeller brake engaged in a manner which clearly...

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Code of Federal Regulations, 2014 CFR

2014-01-01

... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...) Ground locking: A total of 45 hours with the propeller brake engaged in a manner which clearly...

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Code of Federal Regulations, 2013 CFR

2013-01-01

... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...) Ground locking: A total of 45 hours with the propeller brake engaged in a manner which clearly...

Lightweight, low compression aircraft diesel engine. [converting a spark ignition engine to the diesel cycle

NASA Technical Reports Server (NTRS)

Gaynor, T. L.; Bottrell, M. S.; Eagle, C. D.; Bachle, C. F.

1977-01-01

The feasibility of converting a spark ignition aircraft engine to the diesel cycle was investigated. Procedures necessary for converting a single cylinder GTS10-520 are described as well as a single cylinder diesel engine test program. The modification of the engine for the hot port cooling concept is discussed. A digital computer graphics simulation of a twin engine aircraft incorporating the diesel engine and Hot Fort concept is presented showing some potential gains in aircraft performance. Sample results of the computer program used in the simulation are included.

Integrated engine-generator concept for aircraft electric secondary power

NASA Technical Reports Server (NTRS)

Secunde, R. R.; Macosko, R. P.; Repas, D. S.

1972-01-01

The integrated engine-generator concept of locating an electric generator inside an aircraft turbojet or turbofan engine concentric with, and driven by, one of the main engine shafts is discussed. When properly rated, the generator can serve as an engine starter as well as a generator of electric power. The electric power conversion equipment and generator controls are conveniently located in the aircraft. Preliminary layouts of generators in a large engine together with their physical sizes and weights indicate that this concept is a technically feasible approach to aircraft secondary power.

14 CFR 33.64 - Pressurized engine static parts.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Pressurized engine static parts. 33.64 Section 33.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.64 Pressurized...

14 CFR 33.64 - Pressurized engine static parts.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Pressurized engine static parts. 33.64 Section 33.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.64 Pressurized...

14 CFR 33.64 - Pressurized engine static parts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Pressurized engine static parts. 33.64 Section 33.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.64 Pressurized...

14 CFR 34.89 - Compliance with smoke emission standards.

Code of Federal Regulations, 2011 CFR

2011-01-01

... TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 34.89 Compliance with smoke emission... in Appendix 6 to ICAO Annex 16, Environmental Protection, Volume II, Aircraft Engine Emissions...

14 CFR 33.64 - Pressurized engine static parts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pressurized engine static parts. 33.64 Section 33.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.64 Pressurized...

14 CFR 34.89 - Compliance with smoke emission standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 34.89 Compliance with smoke emission... in Appendix 6 to ICAO Annex 16, Environmental Protection, Volume II, Aircraft Engine Emissions...

14 CFR 33.64 - Pressurized engine static parts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pressurized engine static parts. 33.64 Section 33.64 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.64 Pressurized...

14 CFR 21.128 - Tests: aircraft engines.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... engine (except rocket engines for which the manufacturer must establish a sampling technique) to an...

14 CFR 21.128 - Tests: aircraft engines.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... engine (except rocket engines for which the manufacturer must establish a sampling technique) to an...

Image search engine with selective filtering and feature-element-based classification

NASA Astrophysics Data System (ADS)

Li, Qing; Zhang, Yujin; Dai, Shengyang

2001-12-01

With the growth of Internet and storage capability in recent years, image has become a widespread information format in World Wide Web. However, it has become increasingly harder to search for images of interest, and effective image search engine for the WWW needs to be developed. We propose in this paper a selective filtering process and a novel approach for image classification based on feature element in the image search engine we developed for the WWW. First a selective filtering process is embedded in a general web crawler to filter out the meaningless images with GIF format. Two parameters that can be obtained easily are used in the filtering process. Our classification approach first extract feature elements from images instead of feature vectors. Compared with feature vectors, feature elements can better capture visual meanings of the image according to subjective perception of human beings. Different from traditional image classification method, our classification approach based on feature element doesn't calculate the distance between two vectors in the feature space, while trying to find associations between feature element and class attribute of the image. Experiments are presented to show the efficiency of the proposed approach.

Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

NASA Technical Reports Server (NTRS)

Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

1996-01-01

An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

NASA Technical Reports Server (NTRS)

Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

1994-01-01

An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

Advanced Technology Spark-Ignition Aircraft Piston Engine Design Study

NASA Technical Reports Server (NTRS)

Stuckas, K. J.

1980-01-01

The advanced technology, spark ignition, aircraft piston engine design study was conducted to determine the improvements that could be made by taking advantage of technology that could reasonably be expected to be made available for an engine intended for production by January 1, 1990. Two engines were proposed to account for levels of technology considered to be moderate risk and high risk. The moderate risk technology engine is a homogeneous charge engine operating on avgas and offers a 40% improvement in transportation efficiency over present designs. The high risk technology engine, with a stratified charge combustion system using kerosene-based jet fuel, projects a 65% improvement in transportation efficiency. Technology enablement program plans are proposed herein to set a timetable for the successful integration of each item of required advanced technology into the engine design.

The impact of the fuel chemical composition on volatile organic compounds emitted by an in-service aircraft gas turbine engine

NASA Astrophysics Data System (ADS)

Setyan, A.; Kuo, Y. Y.; Brem, B.; Durdina, L.; Gerecke, A. C.; Heeb, N. V.; Haag, R.; Wang, J.

2017-12-01

Aircraft emissions received increased attention recently because of the steady growth of aviation transport in the last decades. Aircraft engines substantially contribute to emissions of particulate matter and gaseous pollutants in the upper and lower troposphere. Among all the pollutants emitted by aircrafts, volatile organic compounds (VOCs) are particularly important because they are mainly emitted at ground level, posing a serious health risk for people living or working near airports. A series of measurements was performed at the aircraft engine testing facility of SR Technics (Zürich airport, Switzerland). Exhausts from an in-service turbofan engine were sampled at the engine exit plane by a multi-point sampling probe. A wide range of instruments was connected to the common sampling line to determine physico-chemical characteristics of non-volatile particulate matter and gaseous pollutants. Conventional Jet A-1 fuel was used as the base fuel, and measurements were performed with the base fuel doped with two different mixtures of aromatic compounds (Solvesso 150 and naphthalene-depleted Solvesso 150) and an alternative fuel (hydro-processed esters and fatty acids [HEFA] jet fuel). During this presentation, we will show results obtained for VOCs. These compounds were sampled with 3 different adsorbing cartridges, and analyzed by thermal desorption gas chromatography/mass spectrometry (TD-GC/MS, for Tenax TA and Carboxen 569) and by ultra-performance liquid chromatography/ mass spectrometry (UPLC/MS, for DNPH). The total VOC concentration was also measured with a flame ionization detector (FID). In addition, fuel samples were also analyzed by GC/MS, and their chemical compositions were compared to the VOCs emitted via engine exhaust. Total VOCs concentrations were highest at ground idle (>200 ppm C at 4-7% thrust), and substantially lower at high thrust (<3 ppm C during take-off, 100% thrust). Fuel samples were dominated by alkanes, whereas VOCs emitted by the aircraft engine were mainly constituted of alkanes, oxygenated compounds, and aromatics. More than 50 % of the compounds identified in the exhaust were not present in the fuel, and thus were formed during combustion. The impact of the fuel doping with aromatics and the alternative fuel on VOCs emitted by the engine will also be discussed.

Lightweight diesel aircraft engines for general aviation

NASA Technical Reports Server (NTRS)

Berenyi, S. G.; Brouwers, A. P.

1980-01-01

A methodical design study was conducted to arrive at new diesel engine configurations and applicable advanced technologies. Two engines are discussed and the description of each engine includes concept drawings. A performance analysis, stress and weight prediction, and a cost study were also conducted. This information was then applied to two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consisted of installation drawings, computer generated performance data, aircraft operating costs and drawings of the resulting airplanes. The performance data shows a vast improvement over current gasoline-powered aircraft. At the completion of this basic study, the program was expanded to evaluate a third engine configuration. This third engine incorporates the best features of the original two, and its design is currently in progress. Preliminary information on this engine is presented.

Aircraft Engine Noise Scattering - A Discontinuous Spectral Element Approach

NASA Technical Reports Server (NTRS)

Stanescu, D.; Hussaini, M. Y.; Farassat, F.

2002-01-01

The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. Our approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Largescale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic con.guration, with and without a wing.

Aircraft Engine Noise Scattering By Fuselage and Wings: A Computational Approach

NASA Technical Reports Server (NTRS)

Stanescu, D.; Hussaini, M. Y.; Farassat, F.

2003-01-01

The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. The approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Large-scale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic configuration, with and without a wing.

Aircraft Engine Noise Scattering by Fuselage and Wings: A Computational Approach

NASA Technical Reports Server (NTRS)

Stanescu, D.; Hussaini, M. Y.; Farassat, F.

2003-01-01

The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. The approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Large-scale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic configuration, with and without a wing.

Optical air data systems and methods

NASA Technical Reports Server (NTRS)

Caldwell, Loren M. (Inventor); Tang, Shoou-Yu (Inventor); O'Brien, Martin J. (Inventor)

2009-01-01

A method for remotely sensing air outside a moving aircraft includes generating laser radiation within a swept frequency range. A portion of the laser radiation is projected from the aircraft into the air to induce scattered laser radiation. Filtered scattered laser radiation, filtered laser radiation, and unfiltered laser radiation are detected. At least one actual ratio is determined from data corresponding to the filtered scattered laser radiation and the unfiltered laser radiation. One or more air parameters are determined by correlating the actual ratio to at least one reference ratio.

Optical air data systems and methods

NASA Technical Reports Server (NTRS)

Caldwell, Loren M. (Inventor); O'Brien, Martin J. (Inventor); Tang, Shoou-Yu (Inventor)

2011-01-01

A method for remotely sensing air outside a moving aircraft includes generating laser radiation within a swept frequency range. A portion of the laser radiation is projected from the aircraft into the air to induce scattered laser radiation. Filtered scattered laser radiation, filtered laser radiation, and unfiltered laser radiation are detected. At least one actual ratio is determined from data corresponding to the filtered scattered laser radiation and the unfiltered laser radiation. One or more air parameters are determined by correlating the actual ratio to at least one reference ratio.

14 CFR 34.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 34.82..., Environmental Protection, Volume II, Aircraft Engine Emissions, Second Edition, July 1993, effective July 26...

14 CFR 34.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 34.82..., Environmental Protection, Volume II, Aircraft Engine Emissions, Second Edition, July 1993, effective July 26...

CID Post-impact fireball

NASA Technical Reports Server (NTRS)

1984-01-01

Following its controlled impact on posts imbedded in the lakebed, the B-720 is sliding sideways and almost enveloped in the large fireball with only the aircraft's nose and right wing-tip exposed. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

CID Post-impact fireball

NASA Technical Reports Server (NTRS)

1984-01-01

The B-720 after impact and sliding through the wing openers is becoming enveloped in a fireball. The right wing appears to be folding over as the aircraft continues to slide. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

CID Aircraft in practice flight above target impact site with wing cutters

NASA Technical Reports Server (NTRS)

1984-01-01

In this photograph the B-720 is seen making a practice close approach over the prepared impact site. The wing openers, designed to tear open the wings and spill the fuel, are clearly seen on the ground just at the start of the bed of rocks. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

The Langley turbo-prop commuter design: A complete project description

NASA Technical Reports Server (NTRS)

Buttram, Greg; Horton, Keith; Keeter, Tim; Millhouse, Paul; Newberry, Kelli; Obyrne, Brian

1991-01-01

The primary objective of this project was to propose and prove the possibility of a new, advanced technology commuter aircraft design. Among the specifications were short to medium range capabilities, low seat per mile cost, fuel efficiency, and passenger comfort. Based on market evaluation, we found that the optimum size for new regional aircraft is around 50 passengers; we have designed our aircraft for this capacity. Turboprop engines provide substantial reductions in operating costs due to lower fuel consumption. We have therefore chosen an advanced turboprop engine. Composite materials, while more expensive to purchase and manufacture, result in decreased costs later through weight savings and ease of replacement.

14 CFR 34.63 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.63 [Reserved] ...

14 CFR 34.63 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 34.63 [Reserved] ...

Aeronautical Engineering. A Continuing Bibliography with Indexes

DTIC Science & Technology

1987-09-01

engines 482 01 AERONAUTICS (GENERAL) i-10 aircraft equipped with turbine engine ...rate adaptive control with applications to lateral Statistics on aircraft gas turbine engine rotor failures Unified model for the calculation of blade ...PUMPS p 527 A87-35669 to test data for a composite prop-tan model Gas turbine combustor and engine augmentor tube GENERAL AVIATION AIRCRAFT

Fuel conservative aircraft engine technology

NASA Technical Reports Server (NTRS)

Nored, D. L.

1978-01-01

Technology developments for more fuel-efficiency subsonic transport aircraft are reported. Three major propulsion projects were considered: (1) engine component improvement - directed at current engines; (2) energy efficient engine - directed at new turbofan engines; and (3) advanced turboprops - directed at technology for advanced turboprop-powered aircraft. Each project is reviewed and some of the technologies and recent accomplishments are described.

A Review of System Identification Methods Applied to Aircraft

NASA Technical Reports Server (NTRS)

Klein, V.

1983-01-01

Airplane identification, equation error method, maximum likelihood method, parameter estimation in frequency domain, extended Kalman filter, aircraft equations of motion, aerodynamic model equations, criteria for the selection of a parsimonious model, and online aircraft identification are addressed.

General Aviation Light Aircraft Propulsion: From the 1940's to the Next Century

NASA Technical Reports Server (NTRS)

Burkardt, Leo A.

1998-01-01

Current general aviation light aircraft are powered by engines that were originally designed in the 1940's. This paper gives a brief history of light aircraft engine development, explaining why the air-cooled, horizontally opposed piston engine became the dominant engine for this class of aircraft. Current engines are fairly efficient, and their designs have been updated through the years, but their basic design and operational characteristics are archaic in comparison to modem engine designs, such as those used in the automotive industry. There have been some innovative engine developments, but in general they have not been commercially successful. This paper gives some insight into the reasons for this lack of success. There is now renewed interest in developing modem propulsion systems for light aircraft, in the fore-front of which is NASA's General Aviation Propulsion (GAP) program. This paper gives an overview of the engines being developed in the GAP program, what they will mean to the general aviation community, and why NASA and its industry partners believe that these new engine developments will bring about a new era in general aviation light aircraft.

Design of a small personal air monitor and its application in aircraft.

PubMed

van Netten, Chris

2009-01-15

A small air sampling system using standard air filter sampling technology has been used to monitor the air in aircraft. The device is a small ABS constructed cylinder 5 cm in diameter and 9 cm tall and can be operated by non technical individuals at an instant notice. It is completely self contained with a 4 AAA cell power supply, DC motor, a centrifugal fan, and accommodates standard 37 mm filters and backup pads. The monitor is totally enclosed and pre assembled in the laboratory. A 45 degrees twist of the cap switches on the motor and simultaneously opens up the intake ports and exhaust ports allowing air to pass through the filter. A reverse 45 degrees twist of the cap switches off the motor and closes all intake and exhaust ports, completely enclosing the filter. The whole monitor is returned to the laboratory by standard mail for analysis and reassembly for future use. The sampler has been tested for electromagnetic interference and has been approved for use in aircraft during all phases of flight. A set of samples taken by a BAe-146-300 crew member during two flights in the same aircraft and analyzed by GC-MS, indicated exposure to tricresyl phosphate (TCP) levels ranging from 31 to 83 nanograms/m(3) (detection limit <4.5 nanograms/m(3)). The latter elevated level was associated with the use of the auxiliary power unit (APU) in the aircraft. It was concluded that the air sampler was capable of monitoring air concentrations of TCP isomers in aircraft above 4.5 nanogram/m(3).

Engine Performance and Knock Rating of Fuels for High-output Aircraft Engines

NASA Technical Reports Server (NTRS)

Rothbrock, A M; Biermann, Arnold E

1938-01-01

Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained on a single-cylinder test engine with aircraft-engine fuels varying from a fuel of 87 octane number to one 100 octane number plus 1 ml of tetraethyl lead per gallon. The data were obtained on a 5-inch by 5.75-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.50 to 8.75. The inlet-air temperature was varied from 120 to 280 F. and the inlet-air pressure from 30 inches of mercury absolute to the highest permissible. The limiting factors for the increase in compression ratio and in inlet-air pressure was the occurrence of either audible or incipient knock. The data are correlated to show that, for any one fuel,there is a definite relationship between the limiting conditions of inlet-air temperature and density at any compression ratio. This relationship is dependent on the combustion-gas temperature and density relationship that causes knock. The report presents a suggested method of rating aircraft-engine fuels based on this relationship. It is concluded that aircraft-engine fuels cannot be satisfactorily rated by any single factor, such as octane number, highest useful compression ratio, or allowable boost pressure. The fuels should be rated by a curve that expresses the limitations of the fuel over a variety of engine conditions.

Flight evaluation of an extended engine life mode on an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, Lawrence P.; Conners, Timothy R.

1992-01-01

An integrated flight and propulsion control system designed to reduce the rate of engine deterioration was developed and evaluated in flight on the NASA Dryden F-15 research aircraft. The extended engine life mode increases engine pressure ratio while reducing engine airflow to lower the turbine temperature at constant thrust. The engine pressure ratio uptrim is modulated in real time based on airplane maneuver requirements, flight conditions, and engine information. The extended engine life mode logic performed well, significantly reducing turbine operating temperature. Reductions in fan turbine inlet temperature of up to 80 F were obtained at intermediate power and up to 170 F at maximum augmented power with no appreciable loss in thrust. A secondary benefit was the considerable reduction in thrust-specific fuel consumption. The success of the extended engine life mode is one example of the advantages gained from integrating aircraft flight and propulsion control systems.

Study of aircraft crashworthiness for fire protection

NASA Technical Reports Server (NTRS)

Cominsky, A.

1981-01-01

Impact-survivable postcrash fire accidents were surveyed. The data base developed includes foreign and domestic accidents involving airlines and jet aircraft. The emphasis was placed on domestic accidents, airlines, and jet aircraft due principally to availability of information. Only transport category aircraft in commercial service designed under FAR Part 25 were considered. A matrix was prepared to show the relationships between the accident characteristics and the fire fatalities. Typical postcrash fire scenaries were identified. Safety concepts were developed for three engineering categories: cabin interiors - cabin subsystems; power plant - engines and fuel systems; and structural mechanics - primary and secondary structures. The parameters identified for concept evaluation are cost, effectiveness, and societal concerns. Three concepts were selected for design definition and cost and effectiveness analysis: improved fire-resistant seat materials; anti-misting kerosene; and additional cabin emergency exits.

Full scale technology demonstration of a modern counterrotating unducted fan engine concept. Engine test

NASA Technical Reports Server (NTRS)

1987-01-01

The Unducted Fan (UDF) engine is an innovative aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio power plant with exceptional fuel efficiency for subsonic aircraft application. This report covers the successful ground testing of this engine. A test program exceeding 100-hr duration was completed, in which all the major goals were achieved. The following accomplishments were demonstrated: (1) full thrust (25,000 lb); (2) full counterrotating rotor speeds (1393+ rpm); (3) low specific fuel consumption (less than 0.24 lb/hr/lb); (4) new composite fan design; (5) counterrotation of structures, turbines, and fan blades; (6) control system; (7) actuation system; and (8) reverse thrust.

Supersonic fan engines for military aircraft

NASA Technical Reports Server (NTRS)

Franciscus, L. C.

1983-01-01

Engine performance and mission studies were performed for turbofan engines with supersonic through-flow fans. A Mach 2.4 CTOL aircraft was used in the study. Two missions were considered: a long range penetrator mission and a long range intercept mission. The supersonic fan engine is compared with an augmented mixed flow turbofan in terms of mission radius for a fixed takeoff gross weight of 75,000 lbm. The mission radius of aircraft powered by supersonic fan engines could be 15 percent longer than aircraft powered with conventional turbofan engines at moderate thrust to gross weight ratios. The climb and acceleration performance of the supersonic fan engines is better than that of the conventional turbofan engines.

Mathematical model of an indirect action fuel flow controller for aircraft jet engines

NASA Astrophysics Data System (ADS)

Tudosie, Alexandru-Nicolae

2017-06-01

The paper deals with a fuel mass flow rate controller with indirect action for aircraft jet engines. The author has identified fuel controller's main parts and its operation mode, then, based on these observations, one has determined motion equations of each main part, which have built system's non-linear mathematical model. In order to realize a better study this model was linearised (using the finite differences method) and then adimensionalized. Based on this new form of the mathematical model, after applying Laplace transformation, the embedded system (controller+engine) was described by the block diagram with transfer functions. Some Simulink-Matlab simulations were performed, concerning system's time behavior for step input, which lead to some useful conclusions and extension possibilities.

Near-field commercial aircraft contribution to nitrogen oxides by engine, aircraft type, and airline by individual plume sampling.

PubMed

Carslaw, David C; Ropkins, Karl; Laxen, Duncan; Moorcroft, Stephen; Marner, Ben; Williams, Martin L

2008-03-15

Nitrogen oxides (NOx) concentrations were measured in individual plumes from aircraft departing on the northern runway at Heathrow Airport in west London. Over a period of four weeks 5618 individual plumes were sampled by a chemiluminescence monitor located 180 m from the runway. Results were processed and matched with detailed aircraft movement and aircraft engine data using chromatographic techniques. Peak concentrations associated with 29 commonly used engines were calculated and found to have a good relationship with N0x emissions taken from the International Civil Aviation Organization (ICAO) databank. However, it is found that engines with higher reported NOx emissions result in proportionately lower NOx concentrations than engines with lower emissions. We show that it is likely that aircraft operational factors such as takeoff weight and aircraftthrust setting have a measurable and important effect on concentrations of N0x. For example, NOx concentrations can differ by up to 41% for aircraft using the same airframe and engine type, while those due to the same engine type in different airframes can differ by 28%. These differences are as great as, if not greater than, the reported differences in NOx emissions between different engine manufacturers for engines used on the same airframe.

75 FR 22439 - Advance Notice of Proposed Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-28

... fuel that is used in commercial aircraft, most military aircraft, or other turbine-engine powered... largely converted to jet turbine-engine propelled aircraft. However, the use of avgas containing 4 grams... or group of sources are the sole or even the major part of an air pollution problem. Moreover...

78 FR 65554 - Exhaust Emission Standards for New Aircraft Turbine Engines and Identification Plate for Aircraft...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Parts 34 and 45 [Docket No.: FAA-2012-1333; Amendment No. 34-5A] RIN 2120-AK15 Exhaust Emission Standards for New Aircraft Turbine Engines and Identification Plate for Aircraft Engines Correction In rule document 2013-24712, appearing on...

Comparison of the Frequency Response and Voltage Tuning Characteristics of a FFP and a MEMS Fiber Optic Tunable Filter

DTIC Science & Technology

2004-05-12

Structural Engineering, La Jolla, CA 92093 14. ABSTRACT Tunable optical filters based on a Fabry - Perot element are a critical component in many...wavelength based fiber optic sensor systems. This report compares the performance of two fiber-pigtailed tunable optical filters, the fiber Fabry - Perot (FFP...both filters suggests that they can operate at frequencies up to 20 kHz and possibly as high as 100 kHz. 15. SUBJECT TERMS Tunable Fabry - Perot filters

Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control

NASA Technical Reports Server (NTRS)

Baer-Riedhart, Jennifer L.; Landy, Robert J.

1987-01-01

The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

Investigation of the misfueling of reciprocating piston aircraft engines

NASA Technical Reports Server (NTRS)

Scott, J. Holland, Jr.

1988-01-01

The Aircraft Misfueling Detection Project was developed by the Goddard Space Flight Center/Wallops Flight Facility at Wallops Island, Virginia. Its purpose was to investigate the misfueling of reciprocating piston aircraft engines by the inadvertent introduction of jet fuel in lieu of or as a contaminant of aviation gasoline. The final objective was the development of a device(s) that will satisfactorily detect misfueling and provide pilots with sufficient warning to avoid injury, fatality, or equipment damage. Two devices have been developed and successfully tested: one, a small contamination detection kit, for use by the pilot, and a second, more sensitive, modified gas chromatograph for use by the fixed-base operator. The gas chromatograph, in addition to providing excellent quality control of the fixed-base operator's fuel handling, is a very good backup for the detection kit in the event it produces negative results. Design parameters were developed to the extent that they may be applied easily to commercial production by the aircraft industry.

14 CFR 33.75 - Safety analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.75 Safety analysis. (a) (1) The applicant must analyze the engine, including the control system, to assess the likely...

14 CFR 34.65-34.70 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) 34.65-34.70 [Reserved] ...

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

Theseus Take-off from Rogers Dry Lake

NASA Technical Reports Server (NTRS)

1996-01-01

The Theseus prototype research aircraft shows off its high aspect-ratio wing in this rear view of the aircraft as it takes off on its first test flight from NASA's Dryden Flight Research Center, Edwards, California, on May 24, 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

Study of a LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine. Previously announced in STAR as N83-34942

Evaluation of all-electric secondary power for transport aircraft

NASA Technical Reports Server (NTRS)

Murray, W. E.; Feiner, L. J.; Flores, R. R.

1992-01-01

This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E; $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.

Evaluation of all-electric secondary power for transport aircraft

NASA Astrophysics Data System (ADS)

Murray, W. E.; Feiner, L. J.; Flores, R. R.

1992-01-01

This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.

Fiber optic controls for aircraft engines - Issues and implications

NASA Technical Reports Server (NTRS)

Dasgupta, Samhita; Poppel, Gary L.; Anderson, William P.

1991-01-01

Some of the issues involved with the application of fiber-optic controls for aircraft engines in the harsh operating environment are addressed, with emphasis on fiber-optic temperature, pressure, position, and speed sensors. Criteria are established to evaluate the optical modulation technique, the sensor/control unit interconnection, and the electrooptic architecture. Single mode and polarization dependent sensor types, sensors which depend on the reflection and/or transmission of light through the engine environment, and intensity-based analog sensors are eliminated as a possible candidate for engine implementation. Fiber-optic harnesses tested for their optical integrity, temperature stability, and mechanical strength, exhibit a capacity to meet mechanical strength requirements and still gain a significant reduction in cable weight.

Assessment of noise in the airplane cabin environment.

PubMed

Zevitas, Christopher D; Spengler, John D; Jones, Byron; McNeely, Eileen; Coull, Brent; Cao, Xiaodong; Loo, Sin Ming; Hard, Anna-Kate; Allen, Joseph G

2018-03-15

To measure sound levels in the aircraft cabin during different phases of flight. Sound level was measured on 200 flights, representing six aircraft groups using continuous monitors. A linear mixed-effects model with random intercept was used to test for significant differences in mean sound level by aircraft model and across each flight phase as well as by flight phase, airplane type, measurement location and proximity to engine noise. Mean sound levels across all flight phases and aircraft groups ranged from 37.6 to >110 dB(A) with a median of 83.5 dB(A). Significant differences in noise levels were also observed based on proximity to the engines and between aircraft with fuselage- and wing mounted engines. Nine flights (4.5%) exceeded the recommended 8-h TWA exposure limit of 85 dB(A) by the NIOSH and ACGIH approach, three flights (1.5%) exceeded the 8-h TWA action level of 85 dB(A) by the OSHA approach, and none of the flights exceeded the 8-h TWA action level of 90 dB(A) by the OSHA PEL approach. Additional characterization studies, including personal noise dosimetry, are necessary to document accurate occupational exposures in the aircraft cabin environment and identify appropriate response actions. FAA should consider applying the more health-protective NIOSH/ACGIH occupational noise recommendations to the aircraft cabin environment.

Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

NASA Technical Reports Server (NTRS)

Hanser, F. A.; Sellers, B.; Briehl, D. C.

1978-01-01

An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

40 CFR 87.23 - Exhaust emission standards for Tier 6 and Tier 8 engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and Tier 8 engines. 87.23 Section 87.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.23 Exhaust emission standards for Tier 6 and Tier 8...

40 CFR 87.23 - Exhaust emission standards for Tier 6 and Tier 8 engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Tier 8 engines. 87.23 Section 87.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.23 Exhaust emission standards for Tier 6 and Tier 8...

14 CFR 21.331 - Issuance of export airworthiness approvals for aircraft engines, propellers, and articles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... for aircraft engines, propellers, and articles. 21.331 Section 21.331 Aeronautics and Space FEDERAL... engines, propellers, and articles. (a) A person may obtain from the FAA an export airworthiness approval to export a new aircraft engine, propeller, or article that is manufactured under this part if it...

14 CFR 21.331 - Issuance of export airworthiness approvals for aircraft engines, propellers, and articles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... for aircraft engines, propellers, and articles. 21.331 Section 21.331 Aeronautics and Space FEDERAL... engines, propellers, and articles. (a) A person may obtain from the FAA an export airworthiness approval to export a new aircraft engine, propeller, or article that is manufactured under this part if it...

14 CFR 21.331 - Issuance of export airworthiness approvals for aircraft engines, propellers, and articles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... for aircraft engines, propellers, and articles. 21.331 Section 21.331 Aeronautics and Space FEDERAL... engines, propellers, and articles. (a) A person may obtain from the FAA an export airworthiness approval to export a new aircraft engine, propeller, or article that is manufactured under this part if it...

14 CFR 21.331 - Issuance of export airworthiness approvals for aircraft engines, propellers, and articles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... for aircraft engines, propellers, and articles. 21.331 Section 21.331 Aeronautics and Space FEDERAL... engines, propellers, and articles. (a) A person may obtain from the FAA an export airworthiness approval to export a new aircraft engine, propeller, or article that is manufactured under this part if it...

Organic positive ions in aircraft gas-turbine engine exhaust

NASA Astrophysics Data System (ADS)

Sorokin, Andrey; Arnold, Frank

Volatile organic compounds (VOCs) represent a significant fraction of atmospheric aerosol. However the role of organic species emitted by aircraft (as a consequence of the incomplete combustion of fuel in the engine) in nucleation of new volatile particles still remains rather speculative and requires a much more detailed analysis of the underlying mechanisms. Measurements in aircraft exhaust plumes have shown the presence of both different non-methane VOCs (e.g. PartEmis project) and numerous organic cluster ions (MPIK-Heidelberg). However the link between detected organic gas-phase species and measured mass spectrum of cluster ions is uncertain. Unfortunately, up to now there are no models describing the thermodynamics of the formation of primary organic cluster ions in the exhaust of aircraft engines. The aim of this work is to present first results of such a model development. The model includes the block of thermodynamic data based on proton affinities and gas basicities of organic molecules and the block of non-equilibrium kinetics of the cluster ions evolution in the exhaust. The model predicts important features of the measured spectrum of positive ions in the exhaust behind aircraft. It is shown that positive ions emitted by aircraft engines into the atmosphere mostly consist of protonated and hydrated organic cluster ions. The developed model may be explored also in aerosol investigations of the background atmosphere as well as in the analysis of the emission of fine aerosol particles by automobiles.

Enhancing Small-Business Opportunities in the DoD

DTIC Science & Technology

2008-01-01

to the DoD is below the small-business share of all industry sales. In some industries , including aircraft manufacturing and engineer - ing services...for goods not included in the Aircraft Manufacturing category as well as those not in another industry category for aircraft engine and engine parts...Purchases, % Small-Business Share of Industry , %, 20022007 2002 Aircraft Manufacturing 2.3 1.8 8.7 Engineering Services 13.6 16.9 20.3 R&D in the

Sampling scheme for pyrethroids on multiple surfaces on commercial aircrafts.

PubMed

Mohan, Krishnan R; Weisel, Clifford P

2010-06-01

A wipe sampler for the collection of permethrin from soft and hard surfaces has been developed for use in aircraft. "Disinsection" or application of pesticides, predominantly pyrethrods, inside commercial aircraft is routinely required by some countries and is done on an as-needed basis by airlines resulting in potential pesticide dermal and inhalation exposures to the crew and passengers. A wipe method using filter paper and water was evaluated for both soft and hard aircraft surfaces. Permethrin was analyzed by GC/MS after its ultrasonication extraction from the sampling medium into hexane and volume reduction. Recoveries, based on spraying known levels of permethrin, were 80-100% from table trays, seat handles and rugs; and 40-50% from seat cushions. The wipe sampler is easy to use, requires minimum training, is compatible with the regulations on what can be brought through security for use on commercial aircraft, and readily adaptable for use in residential and other settings.

Methodology for processing pressure traces used as inputs for combustion analyses in diesel engines

NASA Astrophysics Data System (ADS)

Rašić, Davor; Vihar, Rok; Žvar Baškovič, Urban; Katrašnik, Tomaž

2017-05-01

This study proposes a novel methodology for designing an optimum equiripple finite impulse response (FIR) filter for processing in-cylinder pressure traces of a diesel internal combustion engine, which serve as inputs for high-precision combustion analyses. The proposed automated workflow is based on an innovative approach of determining the transition band frequencies and optimum filter order. The methodology is based on discrete Fourier transform analysis, which is the first step to estimate the location of the pass-band and stop-band frequencies. The second step uses short-time Fourier transform analysis to refine the estimated aforementioned frequencies. These pass-band and stop-band frequencies are further used to determine the most appropriate FIR filter order. The most widely used existing methods for estimating the FIR filter order are not effective in suppressing the oscillations in the rate- of-heat-release (ROHR) trace, thus hindering the accuracy of combustion analyses. To address this problem, an innovative method for determining the order of an FIR filter is proposed in this study. This method is based on the minimization of the integral of normalized signal-to-noise differences between the stop-band frequency and the Nyquist frequency. Developed filters were validated using spectral analysis and calculation of the ROHR. The validation results showed that the filters designed using the proposed innovative method were superior compared with those using the existing methods for all analyzed cases. Highlights • Pressure traces of a diesel engine were processed by finite impulse response (FIR) filters with different orders • Transition band frequencies were determined with an innovative method based on discrete Fourier transform and short-time Fourier transform • Spectral analyses showed deficiencies of existing methods in determining the FIR filter order • A new method of determining the FIR filter order for processing pressure traces was proposed • The efficiency of the new method was demonstrated by spectral analyses and calculations of rate-of-heat-release traces

Characterization of particulate matter and gaseous emissions of a C-130H aircraft.

PubMed

Corporan, Edwin; Quick, Adam; DeWitt, Matthew J

2008-04-01

The gaseous and nonvolatile particulate matter (PM) emissions of two T56-A-15 turboprop engines of a C-130H aircraft stationed at the 123rd Airlift Wing in the Kentucky Air National Guard were characterized. The emissions campaign supports the Strategic Environmental Research and Development Program (SERDP) project WP-1401 to determine emissions factors from military aircraft. The purpose of the project is to develop a comprehensive emissions measurement program using both conventional and advanced techniques to determine emissions factors of pollutants, and to investigate the spatial and temporal evolutions of the exhaust plumes from fixed and rotating wing military aircraft. Standard practices for the measurement of gaseous emissions from aircraft have been well established; however, there is no certified methodology for the measurement of aircraft PM emissions. In this study, several conventional instruments were used to physically characterize and quantify the PM emissions from the two turboprop engines. Emissions samples were extracted from the engine exit plane and transported to the analytical instrumentation via heated lines. Multiple sampling probes were used to assess the spatial variation and obtain a representative average of the engine emissions. Particle concentrations, size distributions, and mass emissions were measured using commercially available aerosol instruments. Engine smoke numbers were determined using established Society of Automotive Engineers (SAE) practices, and gaseous species were quantified via a Fourier-transform infrared-based gas analyzer. The engines were tested at five power settings, from idle to take-off power, to cover a wide range of operating conditions. Average corrected particle numbers (PNs) of (6.4-14.3) x 10(7) particles per cm3 and PN emission indices (EI) from 3.5 x 10(15) to 10.0 x 10(15) particles per kg-fuel were observed. The highest PN EI were observed for the idle power conditions. The mean particle diameter varied between 50 nm at idle to 70 nm at maximum engine power. PM mass EI ranged from 1.6 to 3.5 g/kg-fuel for the conditions tested, which are in agreement with previous T56 engine measurements using other techniques. Additional PM data, smoke numbers, and gaseous emissions will be presented and discussed.

Comparison of the constituents of two jet engine lubricating oils and their volatile pyrolytic degradation products.

PubMed

van Netten, C; Leung, V

2000-03-01

Leaking oil seals in jet engines, at locations prior to the compressor stage, can be a cause of smoke in the cabins of BAe-146 aircraft. Compressed combustion air is bled off to pressurize the cabin and to provide a source of fresh air. Bleed air is diverted from a location just prior to the combustion chamber at a temperature around 500 degrees C. To prevent oil breakdown products from entering the cabin air, catalytic converters have been used to clean the air. During an oil seal failure this device becomes overloaded and smoke is observed in the cabin. Some aircraft companies have removed the catalytic converters and claim an improvement in air quality. During an oil seal failure, however, the flight crew is potentially exposed to the thermal breakdown products of the engine oils. Because very little is known regarding the thermal breakdown products of jet engine lubrication oils, two commercially available oils were investigated under laboratory conditions at 525 degrees C to measure the release of CO, CO2,NO2, and HCN as well as volatiles which were analyzed using GC-Mass spectrometry in an attempt to see if the neurotoxic agents tricresyl phosphates (TCPs) and trimethyl propane phosphate (TMPP) would be present or formed. TMPP was not found in these experiments. Some CO2 was generated along with CO which reached levels in excess of 100 ppm. HCN and NO2 were not detected. GC compositions of the two bulk oils and their breakdown products were almost identical. The presence of TCPs was confirmed in the bulk oils and in the volatiles. Localized condensation in the ventilation ducts and filters in the air conditioning packs are likely the reason why the presence of TCPs has not been demonstrated in cabin air. It was recommended that this needed to be verified in aircraft.

Multidisciplinary conceptual design optimization of aircraft using a sound-matching-based objective function

NASA Astrophysics Data System (ADS)

Diez, Matteo; Iemma, Umberto

2012-05-01

The article presents a novel approach to include community noise considerations based on sound quality in the Multidisciplinary Conceptual Design Optimization (MCDO) of civil transportation aircraft. The novelty stems from the use of an unconventional objective function, defined as a measure of the difference between the noise emission of the aircraft under analysis and a reference 'weakly annoying' noise, the target sound. The minimization of such a merit factor yields an aircraft concept with a noise signature as close as possible to the given target. The reference sound is one of the outcomes of the European Research Project SEFA (Sound Engineering For Aircraft, VI Framework Programme, 2004-2007), and used here as an external input. The aim of the present work is to address the definition and the inclusion of the sound-matching-based objective function in the MCDO of aircraft.

14 CFR 33.62 - Stress analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.62 Stress analysis. A stress analysis must be performed on each turbine engine showing the design safety margin of each turbine...

14 CFR 33.68 - Induction system icing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system icing. Each engine, with all icing protection systems operating, must— (a) Operate throughout its flight power...

14 CFR 34.65-34.70 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) §§ 34.65-34.70 [Reserved] ...