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91.
用于推进的驻定斜爆轰的基本特征 总被引:3,自引:0,他引:3
基于驻定斜爆轰的基本守恒方程、多组元状态方程和考虑化学平衡移动的组元守恒方程,根据本文推导的迭代公式,计算了不同强度的驻定爆轰波后的平衡组分、反应热和绝热指数,讨论了驻定斜爆轰的基本特点、驻定条件和影响驻定的各种因素。 相似文献
92.
This paper proposes a fault-tolerant strategy for hypersonic reentry vehicles with mixed aerodynamic surfaces and reaction control systems (RCS) under external disturbances and subject to actuator faults. Aerodynamic surfaces are treated as the primary actuator in normal situations, and they are driven by a continuous quadratic programming (QP) allocator to generate torque com-manded by a nonlinear adaptive feedback control law. When aerodynamic surfaces encounter faults, they may not be able to provide sufficient torque as commanded, and RCS jets are activated to augment the aerodynamic surfaces to compensate for insufficient torque. Partial loss of effective-ness and stuck faults are considered in this paper, and observers are designed to detect and identify the faults. Based on the fault identification results, an RCS control allocator using integer linear programming (ILP) techniques is designed to determine the optimal combination of activated RCS jets. By treating the RCS control allocator as a quantization element, closed-loop stability with both continuous and quantized inputs is analyzed. Simulation results verify the effectiveness of the proposed method. 相似文献
93.
Three-dimensional computational fluid dynamics analyses have been employed to study the compressible and turbulent flow of the shock train in a convergent–divergent nozzle. The primary goal is to determine the behavior, location, and number of shocks. In this context, full multi-grid initialization, Reynolds stress turbulence model (RSM), and the grid adaption techniques in the Fluent software are utilized under the 3D investigation. The results showed that RSM solution matches with the experimental data suitably. The effects of applying heat generation sources and changing inlet flow total temperature have been investigated. Our simulations showed that changes in the heat generation rate and total temperature of the intake flow influence on the starting point of shock, shock strength, minimum pressure, as well as the maximum flow Mach number. 相似文献
94.
《中国航空学报》2020,33(9):2295-2312
In this paper, a hybrid Lattice Boltzmann Flux Solver (LBFS) with an improved switch function is proposed for simulation of integrated hypersonic fluid-thermal-structural problems. In the solver, the macroscopic Navier–Stokes equations and structural heat transfer equation are discretized by the finite volume method, and the numerical fluxes at the cell interface are reconstructed by the local solution of the Boltzmann equation. To compute the numerical fluxes, two equilibrium distribution functions are introduced. One is the D1Q4 discrete velocity model for calculating the inviscid flux across the cell interface of Navier–Stokes equations, and the other is the D2Q4 model for evaluating the flux of structural energy equation. In this work, a new dual thermal resistance model is proposed to calculate the thermal properties at the fluid–solid interface. The accuracy and stability of the present hybrid solver are validated by simulating several numerical examples, including the fluid-thermal-structural problem of cylindrical leading edge. Numerical results show that the present solver can accurately predict the thermal properties of hypersonic fluid-thermal-structural problems and has the great potential for solving fluid-thermal-structural problems of long-endurance high-speed vehicles. 相似文献
95.
96.
A parameterized geometry design method for inward turning inlet compatible waverider 总被引:1,自引:1,他引:1
Intensive studies have been carried out on generations of waverider geometry and hypersonic inlet geometry. However, integration efforts of waverider and related air-intake system are restricted majorly around the X43A-like or conical flow field induced configuration, which adopts mainly the two-dimensional air-breathing technology and limits the judicious visions of developing new aerodynamic profiles for hypersonic designers. A novel design approach for integrating the inward turning inlet with the traditional parameterized waverider is proposed. The proposed method is an alternative means to produce a compatible configuration by linking the off-the-shelf results on both traditional waverider techniques and inward turning inlet techniques. A series of geometry generations and optimization solutions is proposed to enhance the lift-to-drag ratio. A quantitative but efficient aerodynamic performance evaluation approach (the hypersonic flow panel method) with lower computational cost is employed to play the role of objective function for opti- mization purpose. The produced geometry compatibility with a computational fluid dynamics (CFD) solver is also verified for detailed flow field investigation. Optimization results and other numerical validations are obtained for the feasibility demonstration of the proposed method. 相似文献
97.
用小型涡轮取代蓄电池和高压气瓶作为导弹上的辅助能源是明显地发展趋势.重复进气涡轮能较好地适应这种辅助能源系统的要求.本文研究了涡轮的不同形状的重复进气道,及其与喷嘴的匹配,不同的喷嘴出口角、流速等因素对损失的影响,给出了在所研究的条件下最佳形状的重复进气道、喷嘴和重复进气道的最佳匹配. 相似文献
98.
为验证一种双楔顶压、侧板中置的侧压式进气道基本性能,设计了一套进口面积为110mm×91mm的双流道试验模型,并在300mm马赫数6的高焓脉冲风洞中进行了吹风实验。实验测量了进气道和隔离段内的沿程静压分布和隔离段进出口截面的皮托压力分布,分析了进气道内的典型流场特征,获得了进气道的基本性能参数,并以马赫数的测量为例阐述了流场不均匀性对测量结果可能造成的影响。实验结果表明,马赫数6来流条件下,该侧压式进气道流量系数为0.83,隔离段出口平均马赫数为2.57,总压恢复系数为0.296,增压比为23.7,表明这种侧压式进气道的气动布局方式能够获得较好的总体性能。 相似文献
99.
100.