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MHD Flow Control of Oblique Shock Waves Around Ramps in Low-temperature Supersonic Flows

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Chinese Journal of Aeronautics 2010年第1期23卷 22-32页

作者： Su Changbing,Li Yinghong,Cheng Bangqin,Wang Jian,Cao Jun,Li Yiwen Engineering College,Air Force Engineering University,Xi’an 710038,China Engineering College Air Force Engineering University Xi'an 710038 China

This article is devoted to experimental study on the control of the oblique shock wave around the ramp in a low-temperature supersonic flow by means of the magnetohydrodynamic （MHD） flow control technique. The purpose of the experiments is to take advantage of MHD interaction to weaken the oblique shock wave strength by changing the boundary flow characteristics around the ramp. Plasma columns are generated by pulsed direct current （ DC ） discharge, the magnetic fields are generated by Nd-Fe-B rare-earth permanent magnets and the oblique shock waves in supersonic flow are generated by the ramp. The Lorentz body force effect of MHD interaction on the plasma-induced airflow velocity is verified through particle image velocimetry（PIV）measurements. The experimental results from the supersonic wind tunnel indicate that the MHD flow control can drastically change the flow characteristics of the airflow around the ramp and decrease the ratio of the Pitot pressure after shock wave to that before it by up to 19.66% ,which leads to the decline in oblique shock wave strength. The oblique shock waves in front of the ramp move upstream by the action of the Lorentz body force. The discharge characteristics are analyzed and the MHD interaction time and consumed energy are determined with the help of the pulsed DC discharge images. The interaction parameter corresponding to the boundary layer velocity can reach 1.3 from the momentum conservation equation. The velocity of the plasma column in the magnetic field is much faster than that in the absence of magnetic field force. The plasma can strike the neutral gas molecules to transfer momentum and accelerate the flow around the ramp.

关键词： aerospace propulsion system magnetohydrodynamic flow control plasma shock wave

Progress in research on mixing techniques for transverse injection flow fields in supersonic crossflows

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第8期14卷 554-564页

作者： Wei HUANG Li YAN Science and Technology on Scramjet Laboratory National University of Defense Technology

The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory.

关键词： aerospace propulsion system Transverse injection Mixing Supersonic crossflow

Improving Film Cooling Performance by Using One-Inlet and Double-Outlet Hole

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Journal of Thermal Science 2010年第5期19卷 430-437页

作者： Guang-chao Li and Wei Zhang Aeroengine and Energy Engineering College,Shenyang Areospace University Shenyang China 110136 Aeroengine and Energy Engineering College Shenyang Areospace University Shenyang China

The film cooling performance of a trunk-branch hole is investigated by numerical simulation in this paper. The geometry of the hole is a novel cooling concept, which controls the vortices-pair existing at the mink hole outlet using the injection of the branch hole. The trunk-branch holes require easily machinable round hole as compared to the shaped holes. The flow cases were considered at the blowing ratios of 0.5, 0.75, 1.0, 1.5 and 2.0. At the low blowing ratio of 0.5, the vortices-pair at the outlet of the trunk hole is reduced and the laterally coverage of the film is improved. At the high blowing ratio of 2.0, the vortices-pair is killed by the vortex which is produced by the injection of the branch hole. The flow rate of the two outlets becomes more significantly different when the blowing ratio increases from 0.75 to 2.0. The discharge coefficients increase 0.15 and the laterally averaged film effectiveness improve 0.2 as compared to the cylindrical holes. The optimal blowing ratios occur at M=1.0 or M= 1.5 according to the various locations downstream of the holes.

关键词： aerospace propulsion system gas turbine film cooling heat transfer

Effect of cross-flow direction of coolant on film cooling effectiveness with one inlet and double outlet hole injection

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propulsion and Power Research 2012年第1期1卷 71-77页

作者： Guangchao Lin Chaolin Wu Wei Zhang Zhihai Kou Dawei Peng Liaoning Key Laboratory of Advanced Technology for Aeronautical propulsion system Aeroengine and Energy Engineering CollegeShenyang Aerospace UniversityShenyangLiaoning 110136China

In order to study the effect of cross-flow directions of an internal coolant on film cooling performance,the discharge coefficients and film cooling effectiveness with one inlet and double outlet hole injections were *** numerical results show that two different cross-flow directions of the coolant cause the same decrease in the discharge coefficients as that in the case of supplying coolant by a *** different proportion of the mass flow out of the two outlets of the film hole results in different values of the film cooling effectiveness for three different cases of coolant *** film cooling effectiveness is the highest for the case of supplying coolant by the *** a lower blowing ratio of 1.0,the film cooling effectiveness with coolant injection from the right entrance of the passage is higher than that from the left entrance of the *** a higher blowing ratio of 2.0,the opposite result is found.

关键词： aerospace propulsion system Turbine blade Film cooling Cross-flow Numerical simulation

Discharge Coefficient of 3-in-1 Hole with Various Inclination Angle and Hole Pitch

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Chinese Journal of Aeronautics 2008年第5期21卷 385-392页

作者：李广超朱惠人樊慧明西北工业大学动量与能源学院西安710072

Discharge coefficients of 3-in-1 hole of three inclination angles and three spacing between holes are presented which described the discharge behavior of a row of holes. The inlet and outlet of the 3-in-1 hole both have a 15° lateral expansion. The flow conditions considered are mainstream turbulence intensities and density ratios of secondary flow to mainstream. The momentum flux ratios varied in the range from 1 to 4. The comparison is made of the discharge coefficients of three shaped holes to find an optimal hole with low flow loss. The results show that the discharge coefficients of 3-in- 1 hole are highest in three shaped holes and therefore this article is focused on the measurements of discharge coefficients of 3-in-1 hole for various geometries and aerodynamic parameters. The measured results of 3-in-1 hole indicate that turbulence intensities, density ratios and momentum flux ratios have weak influence on discharge coefficients for inclination angle of 20°. The high turbulence intensity yields the small discharge coefficients for inclination angle of 45° and 90°. The increased both momentum flux ratios and density ratios lead to the increased discharge coefficients for inclination angle of 45° and 90°. The increased inclination angle causes the rapidly increased discharge coefficients. There is a weak dependence of discharge coefficients on hole pitches.

关键词： aerospace propulsion system gas turbine film cooling hole discharge coefficient

Foreign Object Damage to Fan Rotor Blades of Aeroengine Part I:Experimental Study of Bird Impact

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Chinese Journal of Aeronautics 2007年第5期20卷 408-414页

作者：关玉璞南京航空航天大学能源与动力学院

The conditions of experiment for bird impact to blades have been improved. The experiment of bird impact to the fan rotor blades of an aeroengine is carried out. Through analyzing the transient state response of blades impacted by bird and the change of blade profile before and after the impact, the anti-bird impact performance of blades in the first fan rotor is verified. The basis of anti-foreign object damage design for the fan rotor blades of an aeroengine is provided.

关键词： aerospace propulsion system bird impact experiment fan rotor blade transient response

Experimental Investigation of a Fixed-geometry Two-dimensional Mixed-compression Supersonic Inlet with Sweep-forward High- light and Bleed Slot in an Inverted ＂X＂-type Layout

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Chinese Journal of Aeronautics 2007年第4期20卷 304-312页

作者： Wan Dawei Guo Rongwei College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate：（1） with increases of the free stream Mach number, the total pressure recovery decreases, while the mass flow ratio increases to the maximum at the design point and then decreases; （2） when the angle of attack, a, is less than 6°, the total pressure recovery of both side inlets tends to decrease, but, on the lee side inlet, its values are higher than those on the windward side inlet, and the mass flow ratio on lee side inlet increases first and then falls, while on the windward side it keeps declining slowly with the sum of mass flow on both sides remaining almost constant; （3） with the attack angle, a, rising from 6° to 9°, both total pressure recovery and mass flow ratio on the lee side inlet fall quickly, but on the windward side inlet can be observed decreases in the total pressure recovery and increases in the mass flow ratio; （4） by comparing the velocity and back pressure characterristics of the inlet with a bleed slot to those of the inlet without, it stands to reason that the existence of a bleed slot has not only widened the steady working range of inlet, but also made an enormous improvement in its performance at high Mach numbers. Besides, this paper also presents an example to show how this type of inlet is designed.

关键词： aerospace propulsion system supersonic inlet two-dimensional mixed-compression experimental investigation bleed slot "X"-type sweep-forward high-light

A Ventral Diverterless High Offset S-shaped Inlet at Transonic Speeds

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Chinese Journal of Aeronautics 2008年第3期21卷 207-214页

作者：谢文忠郭荣伟南京航空航天大学能源与动力学院江苏南京210016

An investigation on the ventral diverterless high offset S-shaped inlet is carried out at Mach numbers from 0.600 to 1.534, angles of attack from -4° to 9.4°, and yaw angles from 0° to 8°. Results indicate：（1） a large region of low total pressure exists at the lower part of the inlet exit caused by the counter-rotating vortices in the S-shaped duct; （2） the performances of the inlet at Mach number 1.000 reach almost the highest, so the propulsion system could work efficiently in terms of aerodynamics; （3） the total pressure recovery increases slowly at first and then remains unvaried as the Mach number rises from 0.6 to 1.0, however, it does in an opposite manner in the conventional diverter-equipped S-shaped inlet; （4） the performances of the inlet are generally insensitive to angles of attack from -4° to 9.4° and yaw angles from 0° to 8° at Mach number 0.850, and angles of attack from -2° to 6° and yaw angles from 0° to 5° at Mach number 1.534.

关键词： aerospace propulsion system diverterless inlet high offset transonic inlet S-shaped inlet experimental investigation

Foreign Object Damage to Fan Rotor Blades of Aeroengine Part II: Numerical Simulation of Bird Impact

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Chinese Journal of Aeronautics 2008年第4期21卷 328-334页

作者：关玉璞赵振华陈伟高德平南京航空航天大学能源与动力学院南京210016

Bird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carded out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results.

关键词： aerospace propulsion system bird impact numerical simulation fan rotor blade transient response