2008 Vol. 23, No. 5

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Numerical simulation on airfoil stall separation suppression by plasma aerodynamic actuation
LIANG Hua, LI Ying-hong, CHENG Bang-qin, MA Qing-yuan, WU Wei
2008, 23(5): 777-783.
Abstract PDF(1997KB) icon1854 icon451
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The mathematical model of plasma flow control on airfoil was established by solving a two-dimensional fluid model of surface discharge.The body force induced by the plasma aerodynamic actuation was obtained.The momentum and thermal energy were added to the Navier-Stokes equation as source terms.Simulation investigation of plasma flow control on NACA0009 airfoil stall separation suppression was performed under low Reynolds number conditions.The influence of the intensity of the plasma aerodynamic actuation as well as the electrode number and position was investigated.The lift coefficient increased from 0.7449 to 1.2404 and the drag coefficient reduced from 0.4012 to 0.3503 after actuation in the case of Re=58000 at an angle of attack of 24°.
A simple fault diagnosis method for aeroengine performance
WU Ding-yi, XIAO Hong, LIAN Xiao-chun
2008, 23(5): 784-787.
Abstract PDF(1334KB) icon1748 icon476
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A simple fault diagnosis method for aeroengine's performance was developed.Based on component characteristics,this method could detect quickly the inherent change of aeroengine's components and judge the faulty components.Meanwhile,the fault influence of other component can be removed.This method is particularly suitable for finding out aeroengine performance changes between copying engine and typical engine.
Experimental study on coherent structure passive control and drag reduction in turbulent boundary layer with grooved surface
CHANG Yue-feng, JIANG Nan
2008, 23(5): 788-795.
Abstract PDF(1377KB) icon1384 icon523
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The measurement technique of constant temperature anemometry was used to study experimentally the mechanism of drag reduction in turbulent boundary layer with riblet surface.Time sequence signals of longitudinal velocity component and normal velocity component across turbulent boundary layer in the wind tunnel over riblet surface and smooth surface have been finely measured by IFA300 constant temperature anemometer with resolution higher than Kolmogorov scale,together with single-hot-wire-sensor probe and double-hot-wire-sensor probe.The ejection and sweep process of coherent structure burst event were identified by wavelet coefficients of longitudinal fluctuating velocity component.Phased-average waveforms of longitudinal and normal fluctuation velocity,as well as Reynolds stress component of coherent structures burst in turbulent boundary layer were extracted by the conditional sampling technique.The statistic characteristics of coherent structure,such as burst period,phased-average waveforms over riblets surface and smooth surface turbulent boundary layer were compared to clarify the effect of drag reduction over V-grooved riblets surface.The mechanism of drag reduction in turbulent boundary layer over V-grooved riblets surface was studied from the view of multi-scale coherent structure passive control.
An integrated optimization of hypersonic forebody/inlet based on surrogate models
WU Xian-yu, LIU Rui, LUO Shi-bin, WANG Zhen-guo
2008, 23(5): 796-802.
Abstract PDF(820KB) icon1585 icon504
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Asuccessive optimization strategy based on surrogate models was applied to integrated optimization of a hypersonic 2Dforebody/inlet.The sample data points were selected by Latin Hypercubes design of experiment technique,and the sample database was constructed by forebody/inlet flowfield numerical calculation using computational fluid dynamics(CFD) method based on2Dviscous Navier-Stokes equation.Four types of surrogate models including polynomial response surface,Kriging model,BPneural network and radial bases function neural network were adopted.As compared with baseline forebody/inlet at on-design state,the optimal forebody/inlet has better flow capture and compression and total pressure recover capability,and has lower drag force coefficient,with 5.3% improvement of overall performance.The performance of optimal forebody/inlet at off-design states has also improved to some extent.
Theoretical investigation on starting performance of supersonic ejector with secondary throat
WU Ji-ping, WANG Zhen-guo
2008, 23(5): 803-809.
Abstract PDF(1044KB) icon1549 icon496
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A set of fast analysis methods for starting performance of second-throat supersonic ejector was presented.The method of characteristics was introduced to calculate the flow field after the primary nozzle exit,whilst Korst's recompression criterion was adopted to determine the corresponding cell pressure,and one-dimensional control volume method was employed to analyze the downstream flow field.The second-throat area ratio limit,the minimal starting pressure ratio and the corresponding cell pressure were obtained.The influences of primary flow specific heat ratio and three geometric parameters on the starting performance were investigated.The results indicate that lower cell pressure leads to higher minimal starting pressure ratio,and the consistency of the method is quite well.
Durations of transition and variation of boundary-layer thickness before and after breakdown
TANG Hong-tao
2008, 23(5): 810-815.
Abstract PDF(629KB) icon1253 icon377
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Temporal mode direction numerical simulation has been done for the breakdown process of laminar-turbulent transition and the fully developed turbulence in an incompressible boundary layer on a flat plate.Based on the computational results,the common and different characteristics of the durations of transition and the time-averaged boundary-layer thickness induced by different initial disturbances were discussed.Analytical results show that under different basic wave numbers,the durations of transition induced by different initial disturbances are different to one another.On the other hand,under given basic wave numbers,if the initial disturbances are dissymmetrical in span-wise direction,the ratio of the time-averaged boundary-layer thickness after transition to the boundarylayer thickness at the beginning of the breakdown process in the transition,δe/δb,shows the same growth rate with respect to time,which is independent of the initial disturbances.In contrast,initial symmetric disturbances will induce different growth trends.
Characteristic analysis of unstart/restart of hypersonic inlets caused by variations of attack angle of freestream
CHANG Jun-tao, YU Da-ren, BAO Wen
2008, 23(5): 816-821.
Abstract PDF(1122KB) icon2030 icon464
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Unstart/restart is one of most important phenomenon in hypersonic inlets,which affects the operation range and the restart capacity.Atwo-dimensional internal flow field of mixed-compression hypersonic inlets was simulated numerically.The flow characteristics of unstart/restart caused by variations of attack angle were also investigated.The reasons behind the formation of inlet unstart/restart was discussed from the viewpoint of hydrodynamic stability.The inlet performance parameters varying with angle of attack were analyzed.Finally,the condition of inlet restart was discussed.
Study of internal performance for an axisymmetric vectoring exhaust nozzle using numerical simulation
SHAO Wan-ren
2008, 23(5): 822-829.
Abstract PDF(2992KB) icon1477 icon502
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A numerical simulation of internal performance for an axisymmetric vectoring exhaust nozzle was conducted by applying a 3-Dviscous flow program.The effects of model scale and flow temperature on the results of simulation were investigated and the results of the simulation were compared to those of scale model experiments.The internal performance of a real engine in design condition was obtained and the effects of different geometrical angles and nozzle pressure ratios(NPR) on it were discussed.The investigation shows that: model scale and flow temperature have little effect on the internal performance;the results of scale model experiments can truly represent the internal performance of a real engine in design condition;the axisymmetric vectoring exhaust nozzle has excellent internal performance in design condition;and both geometrical angle and NPRaffect the internal performance.
Theoretical model of large-scale eddy motion in plane wall jet flow
YANG Qin, LU Li-peng
2008, 23(5): 830-833.
Abstract PDF(759KB) icon1427 icon425
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Based on the flow stability theory,a two-dimensional instability wave model was proposed to explain the large-scale eddy generated in wall-jet flow.The flow structure patterns and the turbulent quantities obtained by the theoretical model fit well with the experimental results,showing that this theoretical model can describe the major characteristics of large-scale eddy structures in turbulent wall jet flow.
Modification of the turbulence model of DENTON code
LI Qing-liang, LIU Bao-jie
2008, 23(5): 834-839.
Abstract PDF(1203KB) icon2438 icon470
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The mixing length model of DENTONcode was modified to make it fit the development of boundary layer and moderate scale separation,and also reduce the dependence on experience.By comparative calculation and analysis of NASA Rotor 67 and NASA Rotor 37,it shows that the modified model could further improve the computational reliability with little increase of CPUtime,and also maintain the fast advantage of DENTONcode.
Investigation on common nozzle of triple-tube pulse detonation engine with kerosene/air
LI Jian-zhong, WANG Jia-hua, TANG HaoPAN Bo
2008, 23(5): 840-844.
Abstract PDF(806KB) icon1689 icon427
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To explore the feasibility of pulse detonation-turbofan combined engine(PDTE), a whole test system of kerosene/air triple-tube aero-valve pulse detonation engine(PDE) was established.Aconverging nozzle and a converging-diverging nozzle were designed.Within detonation tube of 100 mm in inner diameter and 2000 mm in length,triple-tube PDEcould be operated at 30 Hz in total frequency,and the fully-developed detonation waves were successfully achieved.The effect of interaction among detonation tubes on detonation combustion properties of triple-tube pulse detonation engine was investigated.Because the detonation pressure in tube of triple-tube PDEwith common nozzle was raised,the performance of triple-tube pulse detonation engine was improved.The results lay a basis for preliminary design of practical multi-tube pulse detonation engine.
Thermal performance of staggered mini-duct heat sinks
ZOU Jiang, PENG Xiao-feng, YAN Wei-mou
2008, 23(5): 845-850.
Abstract PDF(974KB) icon1557 icon467
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Experimental investigation was conducted to study the thermal performance and thermal resistance factor of staggered mini-duct heat sinks.With Reynolds number increasing,the performance of both staggered ducts and straight ducts are improved,and the former is more evident and significant.The thermal resistance factor has an exponential relation with Re;and at the same Re,the factor of staggered ducts is about 18% lower than that of straight ducts.The temperature profile of heat sink bottom is distinctly non-uniform,mainly caused by the fluid temperature rise along the flow,and it fluctuates spatially and temporally.The flow in staggered ducts would lose its stability at about Re 700,much lower than normal cases.
Experimental investigation on the effects of base plan angle on flameholders' combustion performance
YANG Yang, MA Wen-jie, FAN Wei-jun, YUE Ming, YANG Mao-lin
2008, 23(5): 851-857.
Abstract PDF(981KB) icon1818 icon499
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The recirculating zone of edge blowing mixture curtain flameholders with base plan angle 60°,120°and 180°was simulated numerically.An experimental investigation of the base plan angle 120°and 180°flameholders atomization,lean limit of the flame stabilization and combustion efficiency was conducted.So,the effects of angle variety of edge base plan on the combustion performance were studied.The test experiments show that,when the base plan angle is 120°,the lean limit of the flame stabilization is wider and combustion efficiency is superior to that of 180°and a Vgutter.It is possible to apply in future afterburner.
Experimental on the effects of jet exit width on EBMC flameholders' combustion performance
YANG Yang, MA Wen-jie, FAN Wei-jun, YUE Ming, YANG Mao-lin
2008, 23(5): 858-864.
Abstract PDF(922KB) icon1912 icon433
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To study the effects of jet exit width on the combustion performance,the combustion performance of edge blowing mixture curtain flameholders(EBMC) and a V gutter with 1mm,2mm or 4mm jet exit width was investigated experimentally under λm =0.1,0.18,0.25 and Tm=573 K,673 K,773 K condition,and the lean limit of the flame stabilization,temperature distribution and combustion efficiency of flameholders were compared and analyzed.The results of combustion experiments show that jet exit width affect EBMC flameholders combustion performance evidently.Under the simulation condition,the lean limit of the flame stabilization is wider when jet exit width is narrower,so lean limit of the flame stabilization of 1mm jet exit width EBMC is widest.The temperature distribution of flameholders shows that high temperature area of narrow jet exit EBMC flameholders is bigger.And combustion efficiency is higher when flameholders jet exit width is narrower,so combustion efficiency of 1mm jet exit width EBMC is highest.
Numerical simulation of supersonic gaseous film cooling
WANG Jian, SUN Bing, WEI Yu-kun
2008, 23(5): 865-870.
Abstract PDF(1390KB) icon2163 icon488
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The SSTk-ω turbulence model was employed to simulate numerically 3Dviscous mixing flow field in order to investigate the supersonic gaseous film cooling injected from different cooling channels tangentially.Results show that blowing rate is an important factor,the adiabatic film cooling effectiveness is enhanced with the increase of the blowing rate.Through different cooling channels,the film cooling has different distribution rules,the cuboids channel is the worst one.The film cooling effectiveness is different between2 kinds of centerlines in the discrete coolant channels,which can be avoided by the β angle.The distribution of adiabatic film cooling effectiveness on the wall indicates that the outspread hole and column with β are better in the foreside,but decline more quickly.3 valuable parameters are introduced to evaluate the supersonic film cooling.
Effect of different fuel-air matching forms on combustion performance of trapped vortex combustor
XING Fei, FAN Wei-jun, LIU Yang, KONG Zhao-jian, LIU Yu-ying, YANG Mao-lin
2008, 23(5): 871-876.
Abstract PDF(1271KB) icon1539 icon431
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To investigate the combustion efficiency and temperature distribution performance of a trapped vortex combustor(TVC)test rig,many experiments were conducted for structural improvement of fuel-air matching under various inlet conditions. Concavity oil supply was applied to TVCduring the experiment in view of the secondary combustion in front of and between turbines.The results of the experiment indicate that,the combustion efficiency could increase by 12%;when the concavity equivalence ratio is less than1.5,the combustion efficiency will reach over 95%;Pattern factor(f) of all the cases is between0.05 and 0.015 in various working conditions.
Preliminary study of wall temperature characteristic of a platelet transpiration cooled thrust chamber
LIN Yang, SUN Bing, ZHENG Li-ming
2008, 23(5): 877-881.
Abstract PDF(617KB) icon1517 icon462
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The preliminary numerical study of wall temperature characteristic of a platelet transpiration cooled thrust chamber was presented.By establishing a one-dimensional liquid-solid coupling non-equilibrium model and using the finites volume method,the temperature distribution of the platelet solid and the coolant liquid along thickness of the thrust chamber was obtained.Meanwhile,the influence of several factors on the wall temperature characteristic was calculated and analyzed,including the flux of coolant,the conductivity of platelet material and the geometry structure of the cooling channels.The numerical results show that the flux of coolant is the most important parameter of controlling the wall temperature,a platelet material of moderate thermal conductivity shall be chosen;a larger width-depth ratio of cooling channels is conducive to the conduction of the platelet toward the coolant,the thermal exchanging efficiency in the cooling channels correlates with the flux of coolant and the thermal conductivity of platelet material.
Unsteady numerical simulation on transonic compressor with screwed slots casing treatment
ZHU Jian-hong, PIAO Ying, Zhou Jian-xing, Qi Xing-ming
2008, 23(5): 882-888.
Abstract PDF(1132KB) icon1619 icon522
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This paper performs time-accurate 3Dunsteady numerical simulations on Rotor37 with cases of screwed slots,slots with cell,and semicircle slots respectively in order to improve casing treatment and acquire lower mass flow at near stall condition.The presented results show that the stall margin increment of slots is closely related to their effects on the leakage flow and their ability to suck the leakage vortex under the help of differential pressure at blade tip.If enough transfer ability is available,the higher the pressure head is,the more powerful the suction will be,and more significant increase will be gained in nearsurge flow stability.The cell on the top of slots can improve the condition of translation with an effect to expand stall margin.And screwed slots angular to the blade can make use of more pressure head between its inlet and outlet to enhance suction;however,non-negligible decreases in efficiency are also observed in this situation.
Analysis of flow in a high specific speed mixed flow compressor
GAO Xing, LIU Bao-jie
2008, 23(5): 889-894.
Abstract PDF(1347KB) icon1597 icon481
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Two high specific speed centrifugal and mixed flow compressors were analyzed numerically using3Dviscous code.The overall performance and flow mechanism of two impellers were also analyzed.The results show that there are similar flow structures in two impellers' inducers.Mixed flow compressor achieves better performance and lower tip leakage loss,and flow field at outlet is more uniform in mixed flow impeller than centrifugal impeller.
Upstream wake-passage vortex interaction in turbine cascade
QI Lei, ZHENG Yun, ZOU Zheng-ping, LIU Huo-xing, LI Wei, ZHOU Ying, XU Ru-qi
2008, 23(5): 895-903.
Abstract PDF(2181KB) icon1616 icon491
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The internal flow of turbomachinery is intrinsically unsteady,so investigating the unsteady interactions in turbine endwall region is meaningful for improving the performance of low aspect/high loading turbine.In this paper,the upstream wake-passage vortex interactions in turbine cascade were simulated by a 3-Dunsteady viscous solver,and the flow mechanisms were analyzed.Numerical results indicate that periodic upstream wakes can enhance the radial vorticity of passage vortex,which increases losses.On the other hand,upstream wakes can suppress the streamwise vorticity development of passage vortex to some extent,which reduces losses.The combined unsteady effect in the endwall region depends on the balance of above two factors.At the calculation conditions of this paper,the unsteady losses finally increased.
3-D numerical analysis of the tip clearance of an aero-engine high pressure turbine
QI Xing-ming, PIAO Ying, ZHU Jian-hong, ZHOU Jian-xing
2008, 23(5): 904-908.
Abstract PDF(974KB) icon1755 icon482
Abstract:
By means of finite element method,the changes of the tip clearance of an aeroengine's high pressure turbine(HPT) were calculated,the influences of pressure,temperature and rotation speed were considered and a new method of applying the boundary conditions was presented as well.After comparison with and analysis of former methods,this paper has reached some reasonable conclusions: the shaft speed plays a major role in the displacement of turbine disc,while the temperature is a major influential factor to the blade and shroud.Minimum tip clearance will occur during the first acceleration of the engine and the re-burst processes,respectively.
Study on regeneratively-cooled technology of full-flow stage combustion thrust chamber
WANG Xiao-wei, JIN Ping, SUN Bing
2008, 23(5): 909-915.
Abstract PDF(754KB) icon2060 icon555
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The full-flow stage combustion(FFSC) cycle engine may be applied in the next generation reusable launch vehicle.In order to meet the enhanced life of FFSCchamber,this paper employed some new technologies developed recently to the regeneratively-cooled thrust chamber for its design work.These technologies include formed platelet technology,high-aspect-ratio cooling passages and elastic cooling structure.While cooling models were established in consideration of the character of FFSCchamber,the modeling of applying these technologies to FFSCchamber was conducted.The results show that these methods can drastically reduce the temperature,the strain of hot-gas-side wall and the coolant pressure drop,and a regeneratively-cooled structure of the FFSCthrust chamber had been preliminarily designed.
Optimization of liquid propellants rocket engine based on genetic algorithm
ZHANG Li-hui, LING Gui-long, DUAN Na, TANG Jia-peng
2008, 23(5): 916-920.
Abstract PDF(703KB) icon1974 icon468
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The system simulation model and the relevant multi-objective optimization model were established for a type of liquid propellants rocket engine,by hybrid algorithm and genetic algorithm.Aiming at FFSC,performance parameters of engine were optimized under kinds of different design variables and objective functions,and got the global optimum solutions.The calculation results showed that genetic algorithm was the most available method to solve such a type of problem,also it could be guidance for other similar engine optimization.
Thrust regulation scheme selection for turbopump-fed rocket engine with variable thrust
ZHANG Jin-rong, JIN Ai-guo, WANG Liang
2008, 23(5): 921-926.
Abstract PDF(600KB) icon1904 icon487
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The development status and application prospect of liquid propellant rocket engine with variable thrust were summarized,and a few adjust scheme for variable thrust of turbopump-fed rocket engine were put forward;their advantages and disadvantages were analyzed,meanwhile several important aspects for adjust scheme selection of turbopump-fed rocket engine were introduced.One turbopump-fed rocket engine was regarded as a model engine to analyze the system parameter balance calculation result for all adjust schemes.Feasible system adjust schemes were determined to facilitate the engineering research and design of model engine.
Influence of outline of missile tail on the thrust of solid motor launching under water
ZHANG You-wei, WANG Xiao-hong
2008, 23(5): 927-931.
Abstract PDF(543KB) icon1514 icon455
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By using the sphere model,the influences of outline of missile tail upon the thrust peak,pressure distribution on the tail and the oscillation character of the thrust for solid motor launching under water are numerically studied.Results indicate that the half-cone-angle of convergent segment has great effect upon thrust peak.The thrust peak decreases slowly as the half-cone-angle is above 45 degree,and decreases quickly as the half-cone-angle is less than45 degree.But the half-cone-angle has very little effect upon the time for thrust reaching the peak.It is also shown that the pressure distribution varies a lot on the convergent segment of the missile tail as thrust reaches the peak value.The half-cone-angle has little effect on the oscillation frequency of thrust.
A model-based diagnosis method of unbalance faults for dual-spool system
HAN Jun, GAO De-ping, HU Xuan
2008, 23(5): 932-938.
Abstract PDF(850KB) icon1656 icon468
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Amodel for analyzing unbalance faults in dual-spool system was discussed.The dual-spool model was built using substructure transfer matrix method.Linear superposition theory was used to calculate the response on the support points when the inner and outer rotors have the unbalance faults at the same time.The method of little rotating speed difference for measuring unbalance vibration response was presented.The nonlinear optimization model for identifying the dual-spool unbalance faults was constructed,and the sequence quadratic programming(SQP) was employed to solve them.The sensibility relationship between the unbalance response from the accessible points and dual rotors speeds,or between the unbalance response and unbalance quantity,were given.The possibility of diagnosis for dual rotors unbalance faults was also discussed.The proposed methods are demonstrated using the numerical simulations and experiments.The results show that the method can successfully identify the magnitude and phase of unbalance for dual-spool using the information of speed and a few points' response data with noise.
Study on grading of health condition of aerospace propulsion system
WANG Yan-kai, LIAO Ming-fu
2008, 23(5): 939-945.
Abstract PDF(2278KB) icon1766 icon493
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Aquantitative evaluation program of health condition of aerospace propulsion system was presented to improve the operability of health condition evaluation of aerospace engines.There are several influential factors to the health of engines,such as: probability of fault,degree of fault and loss risk etc,all of which are random and fuzzy.With fuzzy evaluation theory,then grading of health condition of aerospace propulsion system was confirmed based on maximal membership rule and maximal fatalness rule.Fault simulation was conducted numerically for two sets of engines,showing that this method is applicable and reasonable.
Effect of different heat transfer coefficients on the performance of thermal barrier coatings under thermo-mechanical couple process
LI Zhi-yong, BAO Rui, ZHANG Jian-yu, HU Hao-ju, FEI Bin-jun
2008, 23(5): 946-951.
Abstract PDF(893KB) icon1448 icon440
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The heat insulation and stress distribution in thermal barrier coatings(TBCs) with different inner wall heat transfer coefficients were studied via finite element method(FEM),laying a foundation for the selection of heat transfer coefficients.The results show that,the temperature of model decreases with the increase of the inner wall heat transfer coefficients,meanwhile,the temperature difference between inner and outer walls increases non-linearly.The maximum stress occurs near the thermally grown oxide(TGO) layer,and its value increases with the increase of heat transfer coefficients.
Aeroengine fault diagnosis using dual Kalman filtering technique
ZHANG Peng, HUANG Jin-quan
2008, 23(5): 952-956.
Abstract PDF(836KB) icon1602 icon426
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Adual Kalman filter based health parameters estimation technique was proposed to conduct fault diagnosis of aeroengine components and sensors.Unsteady engine operation measurements were used to solve the diagnosis problem caused by limited amount of available sensors.The reduced sigma point square root unscented Kalman filter(UKF) algorithm could improve the filtering stability and decrease the computational cost greatly.Afault diagnostic simulation was carried out for two-spool turbofan engine components and sensors,showing that the dual Kalman filtering algorithm is an effective aeroengine diagnostic technique.
A decentralized multivariable PI controller for turbofan engine
LI Hua-cong, WU Zhi-kun, ZHU Yu-bin
2008, 23(5): 957-960.
Abstract PDF(1473KB) icon1607 icon491
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Based on the characteristic of model-based intelligent digital engine control,a decentralized multivariable PIcontrol design method for turbofan engine is presented for a given turbofan engine with the direct thrust control mode as an example.The stability of decoupling controller was ensured by employment of the zero assignment method and decentralized control was obtained by using the stability decoupling matrix.Then the PItuning method of SISOwas used to obtain the optimal PIcontroller for each loop.The method was applied to a certain turbofan engine,and the efficiency of dynamic and static decoupling performance of this method is verified by simulation results.

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