Construction of VLCC marine oil storage cost index system

NASA Astrophysics Data System (ADS)

Li, Yuan; Li, Yule; Lu, Jinshu; Wu, Wenfeng; Zhu, Faxin; Chen, Tian; Qin, Beichen

2018-04-01

VLCC as the research object, the basic knowledge of VLCC is summarized. According to the phenomenon that VLCC is applied to offshore oil storage gradually, this paper applies the theoretical analysis method to analyze the excess capacity from VLCC, the drop of oil price, the aging VLCC is more suitable for offshore storage The paper analyzes the reason of VLCC offshore oil storage from three aspects, analyzes the cost of VLCC offshore storage from the aspects of manpower cost and shipping cost, and constructs the cost index system of VLCC offshore oil storage.

Effect of stern hull shape on turning circle of ships

NASA Astrophysics Data System (ADS)

Jaswar, Maimun, A.; Wahid, M. A.; Priyanto, A.; Zamani, Pauzi, Saman

2012-06-01

Many factors such as: stern hull shape, length, draught, trim, propulsion system and external forces affecting the drift angle influence rate of turn and size of turning circle of ships. This paper discusses turning circle characteristics of U and V stern hull shape of Very Large Crude Oil Carrier (VLCC) ships. The ships have same principal dimension such as length, beam, and draught. The turning circle characteristics of the VLCC ships are simulated at 35 degree of rudder angle. In the analysis, firstly, turning circle performance of U-type VLCC ship is simulated. In the simulation, initial ship speed is determined using given power and rpm. Hydrodynamic derivatives coefficients are determined by including effect of fullness of aft run. Using the obtained, speed and hydrodynamic coefficients, force and moment acting on hull, force and moment induced by propeller, force and moment induced by rudder are determined. Finally, ship trajectory, ratio of speed, yaw angle and drift angle are determined. Results of simulation results of the VLCC ship are compared with the experimental one as validation. Using the same method, V-type VLCC is simulated and the simulation results are compared with U-type VLCC ship. Results shows the turning circle of U-type is larger than V-type due to effect stern hul results of simulation are.

Study on zigzag maneuver characteristics of V-U very large crude oil (VLCC) tankers

NASA Astrophysics Data System (ADS)

Jaswar, Maimun, A.; Wahid, M. A.; Priyanto, A.; Zamani, Pauzi, Saman

2012-06-01

The Department of Marine Technology at the Faculty of Mechanical Engineering, University Teknologi Malaysia has recently developed an Ship Maneuverability tool which intends to upgrade student's level understanding the application of fluid dynamic on interaction between hull, propeller, and rudder during maneuvering. This paper discusses zigzag maneuver for conventional Very Large Crude Oil (VLCC) ships with the same principal dimensions but different stern flame shape. 10/10 zigzag maneuver characteristics of U and V types of VLCC ships are investigated. Simulation results for U-type show a good agreement with the experimental data, but V-type not good agreement with experimental one. Further study on zigzag maneuver characteristics are required.

Study of VLCC tanker ship damage stability during off-shore operation

NASA Astrophysics Data System (ADS)

Hanzu-Pazara, R.; Arsenie, P.; Duse, A.; Varsami, C.

2016-08-01

Today, for the carriage of crude oil on sea are used larger tanker ships, especially from VLCC class. The operation of this type of ships requires in many cases special conditions, mainly related to water depth in the terminal area and enough maneuvering space for entrance and departure. Because, many ports from all over the world don't have capacity to operate this type of ships inside, in designed oil terminal, have chosen for development of outside terminals, off-shore oil terminals. In case of this type of terminals, the problems of water depth and manoeuvring space are fixed, but other kind of situations appears, regarding the safety in operation and environment factors impact on ship during mooring at oil transfer buoy. In the present paper we intend to show a study made using simulation techniques about VLCC class tanker ship in case of a damage condition resulted after a possible collision with another ship during loading operation at an off-shore terminal. From the beginning, we take in consideration that the ship intact stability, during all loading possible situations, has to be high enough, so that in case of some damage with flooding of different compartments due to hypothetical dimension water hole, the ship stability in the final stage of flooding to correspond to the requirements for damage stability and, also, to complementary requirements for damage ship stability.

Numerical and experimental investigation of conventional and un-conventional preswirl duct for VLCC

NASA Astrophysics Data System (ADS)

Shin, Hyun-Joon; Lee, Jong-Seung; Lee, Kang-Hoon; Han, Myung-Ryun; Hur, Eui-Beom; Shin, Sung-Chul

2013-09-01

This paper shows the study of preswirl duct as an effective energy saving devices that have been devised and reviewed to support the propeller performance, especially for the ship of VLCC with large block coefficients. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The 2 kinds of pre-swirl duct, Unconventional half circular duct and Conventional circular pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction. The optimum self propulsion tests with various angle configurations were carried out and the best configuration was decided. Accordingly, cavitation test was carried out with best configuration of unconventional half circular duct. The blade surface and tip vortex cavitation behaved smoother when the duct was mounted. The hull pressure amplitudes reflected this difference, so the hull pressure amplitude with duct was smaller than that of without duct.

Optimal structural design of the midship of a VLCC based on the strategy integrating SVM and GA

NASA Astrophysics Data System (ADS)

Sun, Li; Wang, Deyu

2012-03-01

In this paper a hybrid process of modeling and optimization, which integrates a support vector machine (SVM) and genetic algorithm (GA), was introduced to reduce the high time cost in structural optimization of ships. SVM, which is rooted in statistical learning theory and an approximate implementation of the method of structural risk minimization, can provide a good generalization performance in metamodeling the input-output relationship of real problems and consequently cuts down on high time cost in the analysis of real problems, such as FEM analysis. The GA, as a powerful optimization technique, possesses remarkable advantages for the problems that can hardly be optimized with common gradient-based optimization methods, which makes it suitable for optimizing models built by SVM. Based on the SVM-GA strategy, optimization of structural scantlings in the midship of a very large crude carrier (VLCC) ship was carried out according to the direct strength assessment method in common structural rules (CSR), which eventually demonstrates the high efficiency of SVM-GA in optimizing the ship structural scantlings under heavy computational complexity. The time cost of this optimization with SVM-GA has been sharply reduced, many more loops have been processed within a small amount of time and the design has been improved remarkably.

Waterway Shielding System and Method

DTIC Science & Technology

2003-04-30

In early October 12 2002, A French VLCC (Very Large Crude Carrier) chartered by 13 Malaysian state oil company Petronas was attacked by terrorist 14...Combiner 72 may provide a 11 processor with algorithms that are used to add candidates when 12 uncertain and delete candidates when analysis data is fairly...commercial interests that normally have a need to know where 18 shipments of interest on any particular ship are presently 19 located, where competitor

A Study on the Application of New Shaft System for VLCC

NASA Astrophysics Data System (ADS)

Ko, Dae-Eun; Shin, Sang-Hoon

2017-11-01

Some of the most frequent damages in the ship-mounted machinery occur in the propeller shaft system, and the most frequent damage is due to the exothermic accident occurs in the after stern tube bearing (STB). Recently, engine power and shaft diameter of very large crude-oil carriers (VLCCs) tend to increase whereas the distance between forward and after STB becomes shorter. In this study, the applicability of new shaft system for VLCCs adopting single STB system was investigated. The study results show that single STB system is quite possible by applying proper shaft arrangement and partial slope at the white metal. Also, a considerable economic effect is expected by simplifying related shaft system.

Development of energy-saving devices for a full slow-speed ship through improving propulsion performance

NASA Astrophysics Data System (ADS)

Kim, Jung-Hun; Choi, Jung-Eun; Choi, Bong-Jun; Chung, Seok-Ho; Seo, Heung-Won

2015-06-01

Energy-saving devices for 317K VLCC have been developed from a propulsion standpoint. Two ESD candidates were designed via computational tools. The first device WAFon composes of flow-control fins adapted for the ship wake to reduce the loss of rotational energy. The other is WAFon-D, which is a WAFon with a duct to obtain additional thrust and to distribute the inflow velocity on the propeller plane uniform. After selecting the candidates from the computed results, the speed performances were validated with model-tests. The hydrodynamic characteristics of the ESDs may be found in improved hull and propulsive efficiencies through increased wake fraction.

HSA: a heuristic splice alignment tool.

PubMed

Bu, Jingde; Chi, Xuebin; Jin, Zhong

2013-01-01

RNA-Seq methodology is a revolutionary transcriptomics sequencing technology, which is the representative of Next generation Sequencing (NGS). With the high throughput sequencing of RNA-Seq, we can acquire much more information like differential expression and novel splice variants from deep sequence analysis and data mining. But the short read length brings a great challenge to alignment, especially when the reads span two or more exons. A two steps heuristic splice alignment tool is generated in this investigation. First, map raw reads to reference with unspliced aligner--BWA; second, split initial unmapped reads into three equal short reads (seeds), align each seed to the reference, filter hits, search possible split position of read and extend hits to a complete match. Compare with other splice alignment tools like SOAPsplice and Tophat2, HSA has a better performance in call rate and efficiency, but its results do not as accurate as the other software to some extent. HSA is an effective spliced aligner of RNA-Seq reads mapping, which is available at https://github.com/vlcc/HSA.

Ultimate strength performance of tankers associated with industry corrosion addition practices

NASA Astrophysics Data System (ADS)

Kim, Do Kyun; Kim, Han Byul; Zhang, Xiaoming; Li, Chen Guang; Paik, Jeom Kee

2014-09-01

In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSRH) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures

Detailed Analysis of Criteria and Particle Emissions from a Very Large Crude Carrier Using a Novel ECA Fuel.

PubMed

Gysel, Nicholas R; Welch, William A; Johnson, Kent; Miller, Wayne; Cocker, David R

2017-02-07

Ocean going vessels (OGVs) operating within emission control areas (ECA) are required to use fuels with ≤0.1 wt % sulfur. Up to now only distillate fuels could meet the sulfur limits. Recently refiners created a novel low-sulfur heavy-fuel oil (LSHFO) meeting the sulfur limits so questions were posed whether nitric oxide (NO x ) and particulate matter (PM) emissions were the same for the two fuels. This project characterized criteria pollutants and undertook a detailed analysis of PM emissions from a very large crude oil carrier (VLCC) using a distillate ECA fuel (MGO) and novel LSHFO. Results showed emission factors of NO x were ∼5% higher with MGO than LSHFO. PM 2.5 emission factors were ∼3 times higher with LSHFO than MGO, while both were below values reported by Lloyds, U.S. EPA and CARB. A detailed analysis of PM revealed it was >90% organic carbon (OC) for both fuels. Elemental carbon (EC) and soot measured with an AVL microsoot sensor (MSS) reflected black carbon. PM size distributions showed unimodal peaks for both MGO (20-30 nm) and LSHFO (30-50 nm). Particle number (PN) emissions were 28% and 17% higher with the PPS-M compared to the SMPS for LSHFO and MGO, respectively.