To deal with the thermal protection of high speed vehicle, the cooling efficiency of a combinatorial thermal protection configuration which is composed of the forward-facing cavity and opposing jet is investigated. Th...To deal with the thermal protection of high speed vehicle, the cooling efficiency of a combinatorial thermal protection configuration which is composed of the forward-facing cavity and opposing jet is investigated. The numerical simulation result is validated by experiment and the flow field parameters, aerodynamic force and heat flux distribution are obtained. The detailed numerical simulation results show that this kind of combinatorial thermal protection configuration has an excellent effect on cooling the surface of the nosetip. By adding of the opposing jet with a small total pressure, it can avoid the disadvantage to the control performance of the aircraft which is caused by the cavity oscillating flow. And the low stagnation pressure is propitious to simplify the opposing jet system. The location of the recirculation region has a significant impact of the aerodynamic heating. The heat flux along outer body surface of the nosetip does not increase with the stagnation pressure of opposing jet decreases monotonically.展开更多
This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinator...This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.展开更多
Along with the survey on experimental investigations drawing attention to the drag and heat reduction mechanism, the authors simultaneously focus on the recent advances of numerical simulations on the schemes applied ...Along with the survey on experimental investigations drawing attention to the drag and heat reduction mechanism, the authors simultaneously focus on the recent advances of numerical simulations on the schemes applied to supersonic/hypersonic vehicles. The CFD study has evolved as an irreplaceable method in scheme evaluation and aircraft optimization. Similar to our previous experimental survey, the advances in drag and heat reduction schemes are reviewed by similar kinds of mechanism in this article, namely the forward-facing cavity, the opposing jet, the aerospike, the energy deposition and their combinational configurations. This review article puts an emphatic eye on the flow conditions, numerical methods, novel schemes and analytical conclusions given in the simulations. Further, the multi-objective design optimization concept has also been illustrated due to the observable advantages of using CFD over experimental method, especially those performances conducted in drag reduction and thermal protection practice, and this would possess reference value in the design of aircraft system.展开更多
基金supported by the Major Program of National Natural Science Foundation of China (Grant No.90916018)the Research Fund for the Doctoral Program of Higher Education of China (Grant No.2008 99980006)
文摘To deal with the thermal protection of high speed vehicle, the cooling efficiency of a combinatorial thermal protection configuration which is composed of the forward-facing cavity and opposing jet is investigated. The numerical simulation result is validated by experiment and the flow field parameters, aerodynamic force and heat flux distribution are obtained. The detailed numerical simulation results show that this kind of combinatorial thermal protection configuration has an excellent effect on cooling the surface of the nosetip. By adding of the opposing jet with a small total pressure, it can avoid the disadvantage to the control performance of the aircraft which is caused by the cavity oscillating flow. And the low stagnation pressure is propitious to simplify the opposing jet system. The location of the recirculation region has a significant impact of the aerodynamic heating. The heat flux along outer body surface of the nosetip does not increase with the stagnation pressure of opposing jet decreases monotonically.
基金co-supported by National Natural Science Foundation of China (No. 90916018)Research Fund for the Doctoral Program of Higher Education of China (No.200899980006)
文摘This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system （TPS） for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.
基金supported by the Science Foundation of National University of Defense Technology(No.JC14-01-01)a fund for owner of Outstanding Doctoral Dissertation from the Ministry of Education of China(No.201460)
基金support from the National Natural Science Foundation of China (Nos.11502291 & 11802340)
文摘Along with the survey on experimental investigations drawing attention to the drag and heat reduction mechanism, the authors simultaneously focus on the recent advances of numerical simulations on the schemes applied to supersonic/hypersonic vehicles. The CFD study has evolved as an irreplaceable method in scheme evaluation and aircraft optimization. Similar to our previous experimental survey, the advances in drag and heat reduction schemes are reviewed by similar kinds of mechanism in this article, namely the forward-facing cavity, the opposing jet, the aerospike, the energy deposition and their combinational configurations. This review article puts an emphatic eye on the flow conditions, numerical methods, novel schemes and analytical conclusions given in the simulations. Further, the multi-objective design optimization concept has also been illustrated due to the observable advantages of using CFD over experimental method, especially those performances conducted in drag reduction and thermal protection practice, and this would possess reference value in the design of aircraft system.
