Contra‐rotating fans noise prediction for jet engine performance optimization

2008 ◽  
Vol 123 (5) ◽  
pp. 3024-3024
Author(s):  
Dax Au ◽  
Alexandre Leblanc
2007 ◽  
Vol 129 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Elisabet Syverud ◽  
Lars E. Bakken

This paper reports the results of a series of online water wash tests of a GE J85-13 jet engine at the test facilities of the Royal Norwegian Air Force. The engine performance was deteriorated by injecting atomized saltwater at the engine inlet. The engine was then online washed with water injected at three different droplet sizes (25, 75, and 200μm) and at water-to-air ratios ranging from 0.4% to 3% by mass. Engine performance was measured using standard on-engine instrumentation. Extra temperature and pressure sensors in the compressor section provided additional information of the propagation of deposits in the aft stages. The measurements were supported by visual observations. The overall engine performance improved rapidly with online wash. The buildup of deposits in the aft stages was influenced both by the droplet size and the water-to-air ratio. The water-to-air ratio was the most important parameter to achieve effective online washing.


2014 ◽  
Vol 2014 (0) ◽  
pp. _I221-1_-_I221-2_
Author(s):  
Ryosuke Matsuda ◽  
Toshiaki Tuchiya

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Kyunghan Min ◽  
Haksu Kim ◽  
Manbae Han ◽  
Myoungho Sunwoo

Modern diesel engines equip the exhaust gas recirculation (EGR) system because it can suppress NOx emissions effectively. However, since a large amount of exhaust gas might cause the degradation of drivability, the control strategy of EGR system is crucial. The conventional control structure of the EGR system uses the mass air flow (MAF) as a control indicator, and its set-point is determined from the well-calibrated look-up table (LUT). However, this control structure cannot guarantee the optimal engine performance during acceleration operating conditions because the MAF set-point is calibrated at steady operating conditions. In order to optimize the engine performance with regard to NOx emission and drivability, an optimization algorithm in a function of the intake oxygen fraction (IOF) is proposed because the IOF directly affects the combustion and engine emissions. Using the NOx and drivability models, the cost function for the performance optimization is designed and the optimal value of the IOF is determined. Then, the MAF set-point is adjusted to trace the optimal IOF under engine acceleration conditions. The proposed algorithm is validated through scheduled engine speeds and loads to simulate the extra-urban driving cycle of the European driving cycle. As validation results, the MAF is controlled to trace the optimal IOF from the optimization method. Consequently, the NOx emission is substantially reduced during acceleration operating conditions without the degradation of drivability.


2013 ◽  
Vol 860-863 ◽  
pp. 1703-1709 ◽  
Author(s):  
Xian Jun Hou ◽  
Shu Chen ◽  
Zhi'en Liu

A calculation model of turbocharged diesel engine was developed based on one-dimension simulation software GT-power,which can provide a steady boundary condition for the flow field analysis of EGR system.The three-dimension simulation software Fluent was applied in establishing the flow field model of the air-intake system under different air inlet position to analize the distribution of the exhaust gas,and then obtained the impact of the EGRs air-inlet position to uniformity of EGR system, thereby we could acquire the parameters which achieves the best maching between the EGR system and the diesel engine, it also provided a reference for engine performance optimization.


2020 ◽  
Vol 321 ◽  
pp. 04006
Author(s):  
John Mantione ◽  
Matias Garcia-Avila ◽  
Matthew Arnold ◽  
David Bryan ◽  
John Foltz

The attractive combination of strength and low density has resulted in titanium alloys covering 15 to 25% of the weight of a modern jet engine, with titanium currently being used in fan, compressor and nozzle components. Typically, titanium alloys used in jet engine applications are selected from the group of near alpha and alpha-beta titanium alloys, which exhibit superior elevated temperature strength, creep resistance and fatigue life compared to typical titanium alloys such as Ti-6Al-4V. Legacy titanium alloys for elevated temperature jet engine applications include Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-6Al-2Sn-4Zr-2Mo-0.1Si and Ti-4Al-4Mo-2Sn-0.5Si. Improving the mechanical behavior of these alloys enables improved component performance, which is crucial to advancing jet engine performance. As a world leader in supplying advanced alloys of titanium, nickel, cobalt, and specialty stainless steels, ATI is developing new titanium alloys with improved elevated temperature properties. These improved properties derive from precipitation of secondary intermetallics in alpha-beta titanium alloys. ATI has developed several new alpha-beta titanium alloy compositions which exhibit significantly improved elevated temperature strength and creep resistance. This paper will focus on the effects of chemistry and heat treat conditions on the microstructure and resulting elevated temperature properties of these new aerospace titanium alloys.


Author(s):  
R. J. Gill ◽  
D. B. Olson ◽  
H. F. Calcote

Smoke related performance of both jet engine and research combustors has been correlated with several fuel properties. The smoke related data included: smoke number, liner temperature rise, and radiation flux to the combustor wall; fuel parameters included: percent hydrogen, percent aromatic, percent polycyclic aromatic, smoke point, and the threshold soot index, TSI. The research combustor results correlated best with the threshold sooting index. While some correlations with engine performance were excellent, no single fuel property was generally useful in evaluating smoke related performance, mainly because of insufficient data on the fuels tested in the jet engine programs, e.g., percent aromatics specifies a class of fuels which span > 50% of the possible range of sooting tendencies. It is, however, demonstrated that fuel composition plays a dominant role in determining smoke related engine parameters. It is recommended that fuels used for engine testing programs be chemically analyzed in greater detail or be made available for laboratory measurements of soot thresholds and soot yields until a sufficient data base is available to establish a laboratory technique of predicting relative smoke related performance of fuels in jet engines.


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