2022 Vol. 37, No. 1

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Channel layout and shape optimization of active cooling thin-walled structures
SUN Shiping, XU Dehui, LIU Daohuang, HU Zheng
2022, 37(1): 1-10. doi: 10.13224/j.cnki.jasp.20210005
Abstract FullText HTML PDF(1979KB) icon623 icon292
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The design research of an actively fuel-cooled scramjet combustor based on traditional analysis methods has poor versatility and a long period.The substructure method was adopted to establish the fluid solid heat multi field coupling finite element model of the active cooling channel cell，and the effectiveness of the finite element model was verified by comparing with the experimental results.The influence of the number of channels on the heat transfer performance was analyzed when the structure weight and mass flow rate were constant.The super-elliptic function was used to describe the cross-section shape of the channel，and the Kriging response surface and multi-objective genetic algorithm were combined to optimize the channel shape to minimize the average wall temperature，pressure loss and maximum stress.The results showed that：there was an appropriate number of channels to coordinate the performance indicators；the position of the channel did not affect the pressure loss，but the closer channel to the gas wall indicated the better heat transfer performance； the comprehensive performance of the channel shape close to the rectangle was better.Compared with the initial scheme，the average wall temperature and the maximum temperature were reduced by 4.9% and 7.2%，respectively，while the pressure loss was reduced by 33.6 kPa （33.4%）.Therefore，the comprehensive performance of the active cooling thin-walled structure had been improved significantly.
Flow channel scheme of U-shaped cooling channel in scramjet
HU Jiaying, WANG Zhenguo, PAN Yu, LI Peibo
2022, 37(1): 11-25. doi: 10.13224/j.cnki.jasp.20210242
Abstract FullText HTML PDF(3404KB) icon424 icon158
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Three-dimensional simulation of different channel schemes of four channel U-shaped channel plate were conducted.The two configurations of U-shaped channel plate with the same direction inlet/the reverse direction inlet were mainly studied，and the cooling effects of different entrance and exit schemes in each configuration were also discussed and compared.The results showed that the channel scheme with alternate inlet arrangement of the two configurations was more suitable for the regular non-uniform heat flow，the channel scheme with the inlet channel located on both sides of the plate of the two configurations was more suitable for relatively uniform heat flow environment.In the U-shaped channel，the temperature difference between the adjacent channels was large，accompanied by strong heat transfer between the channels，and the lower temperature coolant channel can absorb more heat flow from the combustion chamber wall，which can significantly reduce the cooling burden of the adjacent high temperature channels.
Influences of lattice unit type and arrangement orientation on heat transfer characteristics
LIANG Dong, CHEN Wei, HU Yong, ZHANG Jianpeng, CHYU Minking
2022, 37(1): 26-35. doi: 10.13224/j.cnki.jasp.20210067
Abstract FullText HTML PDF(2337KB) icon651 icon135
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Based on the transient liquid crystals technology and numerical simulation，the influences of truss-type lattice unit type and arrangement orientation on convective heat transfer characteristics for a given porosity were analyzed.Experimental results showed that the convective heat transfer performance was mainly determined by the unit type.Due to excellent heat transfer enhancement，within Reynolds number 5 700-17 100，the staggered body centered cubic-0 （BCC-0） lattice and the Kagome-0 lattice exhibited 9%-21% and 4%-12% higher overall thermal efficiency compared with the pin fin array.In contrast，the inline face centered cubic （FCC） lattices showed a lower heat transfer performance.For the same unit type，choosing a suitable arrangement angle was conducive to further improving the thermal performance.For instance，the thermal efficiency of the Kagome-90 and the BCC-0 were 3%-10% and 5%-15% higher than that of the Kagome-0 and the BCC-45，respectively.
Experiment and numerical calculation on low-temperature oxidation characteristics of RP-3 aviation kerosene
LIU Jing, HU Erjiang, HUANG Zuohua, ZENG Wen
2022, 37(1): 36-45. doi: 10.13224/j.cnki.jasp.20210074
Abstract FullText HTML PDF(1976KB) icon606 icon144
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The low-temperature oxidation of RP-3 aviation kerosene and its surrogate fuel （n-decane （mole fraction of 0.14）/n-dodecane （0.1）/iso-cetane （0.3）/methylcyclohexane（0.36）/toluene （0.1）），were experimentally tested in a jet stirring reactor （JSR） at the conditions of the pressure of 0.1 MPa，the temperature range of 550-1 100 K，the equivalence ratios of 0.5 and 1.0，and the residence time of 2 s.Meanwhile，through the reaction class-based global sensitivity analysis，decoupling methodology and multi-objective genetic algorithm，the reduced reaction kinetic mechanism of the surrogate fuel （including 181 species and 872 reactions） was established，and the low- temperature oxidation characteristics of the surrogate fuel were simulated.The results showed that the temperature-dependent trends of the mole fractions of main species in the low-temperature oxidation process of the surrogate fuel were in good agreement with RP-3 aviation kerosene.The reduced reaction mechanism of the surrogate fuel for RP-3 aviation kerosene had a good prediction of the temperature-dependent trends of the mole fractions of main species during the low-temperature oxidation of the surrogate fuel.However，there were still some deviations in the prediction of the peak mole fractions and negative temperature coefficient （NTC） effect of some species.
Flow boiling characteristics of water in a horizontal tube under hypergravity environment
LI Gen, FANG Xiande, LUO Zufen, QIN Yeqi
2022, 37(1): 46-54. doi: 10.13224/j.cnki.jasp.20210128
Abstract FullText HTML PDF(1416KB) icon339 icon115
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Test on flow boiling frictional pressure drop characteristics of water in a horizontal 1.8 mm inner diameter tube under different hypergravities were conducted by using a centrifugal acceleration machine on the ground.The test conditions were hypergravities of 1.00g-3.16g，mass fluxes of 230 and 330 kg/(m2?s)，heat fluxes of 102 and 141 kW/m2，and vapor qualities from 0.07 up to 0.58.The results showed that different hypergravities，vapor qualities，heat fluxes，and mass fluxes all had effect on the frictional pressure drops of water，and the frictional pressure drops decreased with increasing hypergravities slightly，and increased with increasing vapor qualities significantly.Moreover，the frictional pressure drops increased with increasing both mass flux and heat flux，and the effect of mass flux was more remarkable.The applicability to the test data of eight flow boiling frictional pressure drop correlations developed for normal gravity were evaluated，and the minimum mean absolute deviation and mean relative deviation were 7.8% and 6.9%，respectively，among the correlations.The flow patterns of normal gravity and hypergravity were simulated by using Fluent software because the flow patterns of flow boiling were affected by hypergravities significantly.The simulation results indicated that the effect of hypergravity on flow boiling gas-liquid separation was obvious.
Experiment on primary atomization of flat prefilm nozzle under high temperature and high pressure
ZHANG Juxing, DI Dong, ZHANG Ping, ZHANG Teng, YAN Yingwen, LI Jinghua
2022, 37(1): 55-66. doi: 10.13224/j.cnki.jasp.20210047
Abstract FullText HTML PDF(2468KB) icon407 icon71
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In order to deeply explore the primary atomization mechanism of prefilm nozzle，the influences of different working parameters on the primary atomization characteristics of flat prefilm nozzle under high temperature and high pressure were experimentally studied.The atomization characteristics such as liquid film thickness，liquid film fluctuation pattern and Sauter mean diameter （SMD） of the prefilm plate were obtained by high-speed photography visualization technology and Malvern particle size analyzer.The film thickness of extraction solution was obtained by image post-processing technology.The experimental results showed that the film thickness decreased with the increase of inlet pressure，inlet temperature and inlet Weber number，and increased with the increase of fuel flow rate.Proper orthogonal decomposition （POD） was used to perform fast Fourier transform on the main mode time coefficients of liquid film fluctuation.The experimental results also showed that under the same working conditions，the fluctuation frequency of liquid film presented opposite result with the change of liquid film thickness.When the inlet pressure changed，the inlet Weber number kept unchanged.The experimental results showed that the inlet pressure had no obvious effect on the average size of the final droplet，demonstrating that the inlet Weber number is more suitable for characterizing the fuel atomization effect，and the droplet size decreases with the increase of inlet Weber number.
Characteristics of ethanol spray flame under flow pulsation in swirl burner
CHEN Xiangnan, XIE Dingjiang, MA Kang, TANG Yong, LI Shuiqing, WANG Ningfei, SHI Baolu
2022, 37(1): 67-75. doi: 10.13224/j.cnki.jasp.20210070
Abstract FullText HTML PDF(1622KB) icon375 icon53
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The unsteady combustion behaviors of an ethanol spray flame perturbed by pulsations of different atomizing gaseous flows were investigated experimentally.By varying the atomizing gas flow rate，the responses of flame length and lift-off height to different pulsation frequencies and durations，as well as the flame structure and temperature distribution under flow pulsations，were examined.The results showed that the spray flame changed from attachment to lift-off as the atomizing flow-rate increased.The atomizing process of liquid ethanol was significantly affected by the flow pulsation，resulting in oscillations of flame length and lift-off height at the same frequency.Under the same atomizing flow rate，the average flame length of attached flame and lifting height of lift-off flame increased.The droplet velocity，size and spatial distribution dominating the mixing of ethanol spray and oxidant were directly affected by flow pulsation，resulting in an enhancement of heat-release，while the effect of pulsating frequency was less significant.
Modeling and application test of contact stiffness of bolt connection structure of disk and drum
ZHAO Guang, WANG Yongquan, ZHAO Xiangyang, LI Shengxiang, TENG Guangrong
2022, 37(1): 76-86. doi: 10.13224/j.cnki.jasp.20210065
Abstract FullText HTML PDF(1572KB) icon636 icon195
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In view of the problem of precise modeling and engineering application of the connection stiffness of the bolt connection structure of the aero-engine disk and drum rotor,the relationship between the first six natural frequencies and the bolt preload was obtained through the inherent characteristics test of the bolt structure of the sectorial disk and drum.Considering the stress distribution on the contact surface of the bolts,the variation of natural frequencies of the bolted structure of the sectorial disk and drum with the elastic modulus of the thin-layer element was obtained based on the double-thin-layer element method.The identification of the contact stiffness was realized by constructing the error function of the test and simulation results,and the contact stiffness model was applied to the bolt connection structure of the whole circle drum,which verified the validity and universatility of the model.The results showed that the contact stiffness model established based on the natural frequency test and simulation of sectorial disk and drum structure connected by single bolt had an average identification error of 2.40%.In the bolted structure of the full disk and drum rotor,the average error between simulation and test was 4.10%,which verified the universality of the proposed contact stiffness model.
Design and performance of metamaterials for acoustic-electric energy conversion
LÜ Haifeng, YU Hanhai, YE Junjie, MA Zhiyu, ZHANG Jinghui, LI Jing
2022, 37(1): 87-94. doi: 10.13224/j.cnki.jasp.20210064
Abstract FullText HTML PDF(1366KB) icon599 icon64
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A metamaterial structure for acoustic-electric energy conversation and circuit system combining Helmholtz resonance effect and piezoelectric effect was designed，and the energy band structure of the metamaterial was analyzed by the transfer matrix method.The piezoelectric sheet was used as the Helmholtz resonator substrate to form a metamaterial structure through an array.When the incident noise frequency was consistent with the resonance frequency，the acoustic-electric conversion efficiency was the highest.Using COMSOL to simulate the metamaterial unit and the system respectively，the effect of the metamaterial unit on noise suppression was verified.The influence of the series-parallel mode of the metamaterial unit on the efficiency of acoustic-electric conversion was studied.A rectifier bridge was used to design an alternating current/direct current converter，and super capacitor was adopted to design the energy storage circuit.The test results showed that the optimal direct current load of the designed metamaterials system for acoustic-electric energy conversion was 250 kΩ.With the incident driving of the sound wave at the resonance frequency，the maximum acoustic-electric power of the system was 1 523 μW，which realized the energy conversion，conditioning and energy storage of acoustic-electric.
Hot deformation behavior and hot pressing process optimization of TiB2/7050 particle reinforced aluminum matrix composites
ZHOU Chaoxian, YI Xiaowei, CHEN Chen, CHEN Wei, RAN Gang, WANG Hong
2022, 37(1): 95-102. doi: 10.13224/j.cnki.jasp.20210071
Abstract FullText HTML PDF(1378KB) icon451 icon56
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Analysis on the hot deformation behavior of TiB2/7050 particle-reinforced aluminum-matrix composite and the influence of process parameters is significant for microstructure design and obtaining ideal performance after hot deformation.Based on this，related research on TiB2/7050 particle-reinforced aluminum-matrix composites was carried out.Hot compression experiments were carried out on Gleeble-3500 thermal simulator to study the hot deformation behavior of TiB2/7050 particle-reinforced aluminum-matrix composites at deformation temperature of 300-450 ℃ and strain rate of 0.001-1 s-1，and the hyperbolic sine constitutive equation of the material was established.According to the dynamic material model，the processing map was calculated，and the processing window of the material was optimized.The mechanical properties and microstructure of the original extruded billet and the optimized hot pressed billet were analyzed.Results showed that，comparing these two processes，the strength index of hot pressed parts was slightly improved，but the plasticity was greatly improved，and the elongation after long transverse fracture was increased by 400%；the grain size of hot pressed parts was smaller and there was no obvious preferred orientation；the mechanism of tensile fracture was quasi cleavage fracture.The dimples of fracture surface of the hot pressed parts were deeper and the tearing edges were larger，indicating the longer duration of plastic tearing.
Multi-objective optimization design for vibration parameters of nonlinear hard-coating blisk
GAO Feng, LIU Xiuting, YU Bin
2022, 37(1): 103-113. doi: 10.13224/j.cnki.jasp.20200566
Abstract FullText HTML PDF(1800KB) icon334 icon68
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To optimize the damping vibration reduction of strain-dependent hard coating on the blisk，the multi-objective optimization design for coating parameters of the nonlinear hard-coating blisk was conducted.The vibration characteristics of hard-coating blisk was analyzed using the energy-based finite element method with reference to the composite Mindlin plate theory associated with the unified iterative calculation technique based on the Newton-Raphson method；the multi-objective optimization problems for coating parameters of hard-coating blisk were solved by the NSGA-Ⅲ algorithm，and the optimization results were expressed as Pareto front solutions；an academic blisk with NiCoCrAlY+YSZ hard coating on blades，taken as the specific case study benchmark，was selected to conduct the bi-objective and triple-objective optimization design for coating parameters.The results revealed that the effect of the coating parameters on the vibration characteristics of blisk was constrained mutually，the coating parameters located at the “turning point” in Pareto front solutions can balance all aspects of design performance on the vibration characteristics of hard-coating blisk，and the obtained coating parameters can also be referenced according to the practical engineering requirements.
Numerical study on leakage and dynamic characteristics of circumferentially divergent pocket damping seal
BAI Lu, SUN Dan, ZHAO Huan, XIAO Zhonghui, MENG Jigang, HU Yong
2022, 37(1): 114-123. doi: 10.13224/j.cnki.jasp.20210076
Abstract FullText HTML PDF(2329KB) icon424 icon50
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A type of circumferentially divergent pocket damping seal structure was proposed，the pocket damping seal multi-frequency elliptical vortex solution model was established，and based on the experimental verification of the accuracy of the pocket damping seal solution model，the effects of the inlet and outlet pressure ratio and eccentricity on the leakage characteristics and dynamic characteristics of pocket damping seal were studied，and the rotor stability of the pocket damping seals was analyzed.The research results showed that the difference in leakage between two pocket damping seals was 0.89% on average，and the leakage characteristics of these two were equivalent.The traditional pocket damping seal had a large circumferential pressure difference in each chamber when the rotor was eccentric，while the pressure distribution in each chamber of the circumferentially divergent pocket damping seal was basically uniform； the tangential airflow force of these two was opposite to the direction of the rotor whirl，and both suppressed the vortex of the rotor，and the tangential air force of the circumferentially divergent pocket damping seal was 2.29 times that of the traditional pocket damping seal；the average effective stiffness of the circumferentially divergent pocket damping seal was 1.29 times that of the traditional pocket damping seal，the circumferentially divergent pocket damping seal was more conducive to the stability of the rotor system.
Conceptual configuration aerodynamic performance of heat flux and drag reduction in high speed rarefied flow
ZHANG Shuai
2022, 37(1): 124-141. doi: 10.13224/j.cnki.jasp.20200541
Abstract FullText HTML PDF(3983KB) icon298 icon70
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To investigate the heat flux and drag reduction characteristics of the space vehicle combining the forward-facing cavity and the channel in high speed rarefied flow，numerical study of aerodynamic and aerothermodynamics performance on the space vehicle was conducted via direct simulation Monte Carlo （DSMC） method.Two groups of combinations were established.The aspect ratio of forward-facing cavity was set as 1.The first series of channel with channel heights of 0，10，20，30，40 mm，and the second series of lip bluntness with lip passivation radius of 2-20 mm and the baseline channel height with constant 20 mm had been taken into consideration.Results of the work for applying the cavity-channel concept to space vehicle showed a proposing heating and drag reduction performance.Compared with the original blunt cone，the cavity-channel configuration with channel height of 20 mm had the optimal performance within the range considered，and the heat flux and drag reduction rates reached approximately 6.99% and 4.44%，respectively.Higher channel height indicated better drag reduction，but the heat protection effectiveness was weakened.The gas inside the cavity changed from rarefied flow to continuous flow and the gas pressure oscillated.There could bring about apparent advantages of heat reduction without any drag increment penalty by employing cavity lip bluntness.
Influence of outboard nacelle chine on the low-speed characteristics of civil transport aircraft
WANG Qimin, ZHENG Longqian, ZHANG Meihong
2022, 37(1): 142-151. doi: 10.13224/j.cnki.jasp.20210333
Abstract FullText HTML PDF(2427KB) icon356 icon68
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For the purpose of improving the aerodynamic performance of the civil transport aircraft with the high-lift devices deployed at high angle of attack，the numerical simulation method of Reynolds average Navier-Stokes （RANS） turbulence model was used to analyze the stall characteristics of aircraft with the wing-mounted nacelle configuration.The mechanism of the outboard nacelle chine was investigated.Design exploration of the installation position and angle of the outboard nacelle chine was carried out.The vortex from the outboard slat and main wing aggravated the flow separation on the wing upper surface behind the nacelle/pylon.The vortex induced by designed outboard nacelle chine suppressed the flow separation，which increased the maximum lift coefficient.The installation position of the outboard nacelle chine affected the intensity，spanwise position and height of the induced vortex.The installation angle mainly affected the induced vortex intensity.The maximum lift coefficient increased by 2.1% with the outboard nacelle chine.
Ground starting modeling and control law design method of variable cycle engine
HAO Wang, WANG Zhanxue, ZHANG Xiaobo, ZHOU Li, WANG Jingkai
2022, 37(1): 152-164. doi: 10.13224/j.cnki.jasp.20210132
Abstract FullText HTML PDF(1917KB) icon652 icon142
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To solve the problem of discontinuous isentropic efficiency of rotating components，a method of using correct torque instead of isentropic efficiency was proposed.The extrapolation method of low speed characteristics of rotating components was given，and the full speed characteristics of rotating components were obtained.A burner stability model considering ignition and burn stability was proposed.Finally，a component-level starting model of the variable cycle engine was established.Considering the eight variable parameters of the variable cycle engine，the differential evolution algorithm was used to optimize the starting process of the variable cycle engine in the double bypass and single bypass modes.The results showed that the starting time of the variable cycle engine in the double bypass and single bypass modes was 17.2 s and 12.8 s，respectively.In the double bypass mode，the fuel flow，nozzle throat area and outer bypass area of rear variable area bypass injector need to be adjusted.In the single bypass mode，the fuel flow，nozzle throat area and low pressure turbine inlet guide vane area need to be adjusted.When the free stream Mach number was equal to 0.04，the starting time of the variable cycle engine in the double bypass and single bypass modes was 0.2 s less than the static state.
Experiment on influence of front/after-mounted propeller on turboprop engine performance
WEI Yuqing, GUO Feng, ZHU Jianfeng, LI Wei, HUANG Xing
2022, 37(1): 165-172. doi: 10.13224/j.cnki.jasp.20210562
Abstract FullText HTML PDF(1207KB) icon598 icon96
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Based on a 15 kW turboprop engine，a test rig for a biased inlet adopting a front/after-mounted propeller configuration was built.And the influence of the front/after-mounted propeller configurations on the performance of turboprop engine was investigated.The results showed that：with the increase of the gas turbine speed，the pressurization effect of the propeller slipstream was enhanced and the airflow loss in the inlet duct increased.The pressurization effect of propeller slipstream was 0.35% and 0.7% at the relative corrected speed of 64% and 88%，respectively.It showed that when adopting the front-mounted configuration，the total pressure recovery coefficient of propeller/intake duct system was basically maintained at 100%；limited by both the slipstream pressurization effect from the front-mounted propeller and the power loss of the external transmission shaft，the engine pull was almost the same at the same gas turbine speed no matter the propeller was mounted front or rear，but the speed of the propeller in the rear position increased by 2.8%-4%，and the outlet exhaust temperature increased by 11-22 ℃；For the after-mounted propeller configuration，the distortion pattern was characterized by a relatively high pressure distribution at its upper part.In contrast，for the front-mounted configuration，since the airflow accumulated at the lower right corner along the direction of the propeller rotation，the distortion pattern at the outlet of inlet duct showed a distribution of high pressure in the lower right corner and low pressure in the upper left corner.And the total pressure distortion index decreased.
Design and test of temperature distortion generator on small flow rate compressor
ZHANG Jun, ZHU Ling, SHI Jiancheng, WANG Guowen, YIN Yueqian
2022, 37(1): 173-180. doi: 10.13224/j.cnki.jasp.20210068
Abstract FullText HTML PDF(1229KB) icon435 icon82
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A small flow compressor temperature distortion generator was designed by using electric heating tubes.The operation parameters of the temperature distortion generator were calibrated with temperature distortion coefficient，and the total pressure recovery coefficient and pressure distortion coefficient were obtained.The temperature distortion generator was installed on the compressor test rig，and the aerodynamic performance of the compressor under the condition of temperature distortion was obtained.The results showed that 4-5 electric heating tubes were required to meet the requirements of temperature distortion coefficient，and the power of a single tube was 3 kW.The inlet physical mass flow must be less than 3 kg/s.Under the operating parameters of the distortion generator，the peak efficiency of the compressor decreased by 1.3% at most，and the surge line had no significant change.
Coupling model of self- and external-excitation for phenomena in pulsed jet flow control
LU Weiyu, HUANG Guoping, YANG Yuxuan
2022, 37(1): 181-190. doi: 10.13224/j.cnki.jasp.20210069
Abstract FullText HTML PDF(941KB) icon428 icon67
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In order to explain four phenomena such as frequency-dependent，position-dependent，synchronization and intensity-dependent effects in pulsed jet flow control，a simplified coupling model of self- and external- excitation was established to approximately describe pulsed jet flow control based on the flow stability theory with weak nonlinearity.Composed of two partial differential equations，the model can be simplified as ordinary differential equations for solution in particular cases.By comparing the model results with those from numerical simulation and experiment of pulsed jet flow control，it can be found that the coupling model can qualitatively or semi-quantitatively reflect the four phenomena in actual pulsed jet flow control.Further analysis of the model showed that the pulsed jet mainly used the nonlinear flow instability mechanism to promote the momentum transfer between the main flow and the separated flow by making the flow field synchronize with unsteady excitation.As a result of self- and external- excitation coupling，flow control effects were realized and four typical and unique phenomena were presented.
Study on the mechanism of stability improvement of the self-recirculating casing treatment in a counter-rotating compressor
GUO Yanchao, GAO Limin, YANG Guanhua, WANG Lei
2022, 37(1): 191-203. doi: 10.13224/j.cnki.jasp.20210009
Abstract FullText HTML PDF(2721KB) icon562 icon113
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In order to broaden the application range of self-recirculating casing treatment（SRCT），a counter-rotating compressor was used as the research object.The stability enhancement mechanism of SRCT and the effect of axial injection position on its stability expansion ability were studied by numerical method.The overall characteristics of the counter-rotating compressor and the change of rotor tip flow field with/without self-recirculating casing treatment were analyzed in detail.The results showed that considerable stall margin improvement can be obtained by configuring a self-recirculating casing on the rotor that stalled first，but the axial injection position had an important effect on the stability improvement effect and the aerodynamic performance of the counter-rotating compressor.The axial injection position should not be too close to the leading edge of the blade；when the injection position was 40% of the axial chord length from the leading edge of the blade，the improvement of stall margin was 7.73% and the peak efficiency loss was minimum.Self-recirculating casing treatment can delay stall by reducing blade tip load，weakening the strength of the tip secondary leakage flow and restraining the mixing of the tip leakage flow and main flow.The first stall stage of counter-rotating compressor can be changed by self-recirculating casing treatment，without change of the stall initiation type.
Reconfiguration control of launch vehicle based on Armijo criterion and BFGS algorithm
YU Haisen, TAN Shujun, WU Zhigang
2022, 37(1): 204-213. doi: 10.13224/j.cnki.jasp.20210059
Abstract FullText HTML PDF(1543KB) icon438 icon49
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Taking a new type of launch vehicle as the research object，the problem of reconfiguration control under servo mechanism fault was studied.The problem was transformed into a constrained quadratic programming problem，and then a control allocation method combining the Armijo criterion and BFGS algorithm was used to solve the problem.Armijo criterion can ensure the convergence of the optimization algorithm，while BFGS algorithm avoided the inversion of Hesse matrix in the iterative process，and had the advantage of fast convergence.The proposed reconstruction method was compared with the fixed point iterative algorithm.After 8 iterations，the objective function value and error value converged to about 102 magnitude and 10-5 magnitude，respectively.However，the fixed point iterative algorithm was not completely converged after 30 iterations，and the objective function value and error converged to about 103 magnitude and 10-2 magnitude，respectively.The results showed that the reconstruction method converged faster and had higher convergence precision than the fixed point iterative algorithm.Taking a single engine stuck fault as an example，the simulation results showed that the control effect was the same as that in the case of no fault，which verified the validity and correctness of the proposed method.
Optimization design for nozzle contour of rocket engine based on response surface method
WANG Yingpeng, XU Yihua, SUN Haijun, FENG Xiping
2022, 37(1): 214-224. doi: 10.13224/j.cnki.jasp.20210004
Abstract FullText HTML PDF(1630KB) icon614 icon124
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Based on the known gas parameters of a certain rocket engine，the performance of nozzle with convergent section designed by Witoszynski，bicubic curve，quintic curve and axis shifting method based on Witoszynski was analyzed on a comparative basis.Better performance of nozzle was obtained by axis shifting method.The nozzle contour parameters （initial arc radius of arc segment，outlet half angle，length diameter ratio of expansion section） were calculated and analyzed by single variable method.The results showed that the nozzle outlet thrust decreased with the increase of the initial expansion arc radius and outlet half angle； with the increase of the length diameter ratio of the convergent section，the length diameter ratio of the expansion section and the expansion angle，the nozzle outlet thrust first increased and then decreased.Due to the interact phenomenon of the influence of the parameters of each contour，the response surface method （RSM） was used to optimize the parameters of nozzle contour in order to comprehensively consider the influence of various parameters on nozzle performance.The results showed that the length of the performance of nozzle contour obtained by RSM was reduced by 3.40% with the increase of thrust.

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