The new regenerative cooling thermal protection system exhibits the multifunctional characteristics of load-carrying and heat exchange cooling,which are fundamental for the lightweight design and thermal protection of...The new regenerative cooling thermal protection system exhibits the multifunctional characteristics of load-carrying and heat exchange cooling,which are fundamental for the lightweight design and thermal protection of hypersonic vehicles.Triply periodic minimal surface(TPMS)is especially suitable for the structural design of the internal cavity of regenerative cooling structures owing to its excellent structural characteristics.In this study,test pieces were manufactured using Ti6Al4V lightweight material.We designed three types of porous test pieces,and the interior was filled with a TPMS lattice(Gyroid,Primitive,I-WP)with a porosity of 30%.All porous test pieces were manufactured via selective laser melting technology.A combination of experiments and finite element simulations were performed to study the selection of the internal cavity structure of the regenerative cooling thermal protection system.Hence,the relationship between the geometry and mechanical properties of a unit cell is established,and the deformation mechanism of the porous unit cell is clarified.Among the three types of porous test pieces,the weight of the test piece filled with the Gyroid unit cell was reduced by 8.21%,the average tensile strength was reduced by 17.7%compared to the solid test piece,while the average tensile strength of the Primitive and I-WP porous test pieces were decreased by 30.5%and 33.3%,respectively.Compared with the other two types of unit cells,Gyroid exhibited better mechanical conductivity characteristics.Its deformation process was characterised by stretching,shearing,and twisting,while the Primitive and I-WP unit cells underwent tensile deformation and tensile and shear deformation,respectively.The finite element predictions in the study agree well with the experimental results.The results can provide a basis for the design of regenerative cooling thermal protection system.展开更多
A platelet transpiration cooled nosetip is considered as thermal protection system （TPS） to prevent hypersonic ve- hicle from the serious aerodynamic heating. Based on the one dimensional flow model, a distribution ...A platelet transpiration cooled nosetip is considered as thermal protection system （TPS） to prevent hypersonic ve- hicle from the serious aerodynamic heating. Based on the one dimensional flow model, a distribution model of coolant is proposed for the temperature calculation. When Si = Sj （i, j=1,… 24）, the first cooling effect parameter Pmax is proposed and its relationship with total mass flux and Sc0/Si is investigated. The result shows that Pmax increases while the total mass flux increases, and when the mass flux is fixed, Pmax increases rapidly at the be- ginning and then turns to a nearly stable value while Sc0/Si increases. Then under the precondition of cooling ef- fect, we fix Sc0/Si to insure there is enough space for the pipe. Numerical investigation shows the design of the nosetip makes the transpiration cooling extremely effective. In order to reduce the temperature difference on the nosetip, the second cooling effect parameter Pdiff is proposed and different Pdiff with different 0gi （i=1,..., 23） are analyzed. According to the cases we design, Pdiff decreases while the upstream 0gi decreases or the down- stream 0gi increases. The best result among cases shows Pdiff is reduced by 15.1%.展开更多
Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a...Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a transpiration cooling thermal protection system was designed and manufactured,and an experiment platform with radiant heating at the bottom as heat source was developed. The cooling capacity of the transpiration cooling TPS was experimentally investigated. By combining transpiration cooling method with traditional TPS,the heat load capability of the TPS can be improved. The structure temperature with active cooling applied was much lower than that without active cooling applied under the same heat load as well as the heat load increased with active cooling than the one without active cooling for the same structure temperature. The experimental results showed that at 5800 s,the temperature of inner structure was 100°C with active cooling applied compared to 500°C without active cooling applied,then the temperature increased and reached to 360°C at 8300 s. Heat load of this transpiration cooling TPS can be increased by over 70% as compared to the passion one and the cooling capability of the transpiration TPS was about 1700 kJ/kg. The results can provide fundamental data for developing the transpiration cooling TPS.展开更多
基金support from the National Natural Science Foundation of China(NSFC,Project Nos.91860136 and 51801231)the Key R&D Plan of Guangdong Province(Grant No.2018B090905001)the Key Science and Technology project of Shaanxi Province(Grant No.2018zdzx01-04-01).
文摘The new regenerative cooling thermal protection system exhibits the multifunctional characteristics of load-carrying and heat exchange cooling,which are fundamental for the lightweight design and thermal protection of hypersonic vehicles.Triply periodic minimal surface(TPMS)is especially suitable for the structural design of the internal cavity of regenerative cooling structures owing to its excellent structural characteristics.In this study,test pieces were manufactured using Ti6Al4V lightweight material.We designed three types of porous test pieces,and the interior was filled with a TPMS lattice(Gyroid,Primitive,I-WP)with a porosity of 30%.All porous test pieces were manufactured via selective laser melting technology.A combination of experiments and finite element simulations were performed to study the selection of the internal cavity structure of the regenerative cooling thermal protection system.Hence,the relationship between the geometry and mechanical properties of a unit cell is established,and the deformation mechanism of the porous unit cell is clarified.Among the three types of porous test pieces,the weight of the test piece filled with the Gyroid unit cell was reduced by 8.21%,the average tensile strength was reduced by 17.7%compared to the solid test piece,while the average tensile strength of the Primitive and I-WP porous test pieces were decreased by 30.5%and 33.3%,respectively.Compared with the other two types of unit cells,Gyroid exhibited better mechanical conductivity characteristics.Its deformation process was characterised by stretching,shearing,and twisting,while the Primitive and I-WP unit cells underwent tensile deformation and tensile and shear deformation,respectively.The finite element predictions in the study agree well with the experimental results.The results can provide a basis for the design of regenerative cooling thermal protection system.
文摘A platelet transpiration cooled nosetip is considered as thermal protection system （TPS） to prevent hypersonic ve- hicle from the serious aerodynamic heating. Based on the one dimensional flow model, a distribution model of coolant is proposed for the temperature calculation. When Si = Sj （i, j=1,… 24）, the first cooling effect parameter Pmax is proposed and its relationship with total mass flux and Sc0/Si is investigated. The result shows that Pmax increases while the total mass flux increases, and when the mass flux is fixed, Pmax increases rapidly at the be- ginning and then turns to a nearly stable value while Sc0/Si increases. Then under the precondition of cooling ef- fect, we fix Sc0/Si to insure there is enough space for the pipe. Numerical investigation shows the design of the nosetip makes the transpiration cooling extremely effective. In order to reduce the temperature difference on the nosetip, the second cooling effect parameter Pdiff is proposed and different Pdiff with different 0gi （i=1,..., 23） are analyzed. According to the cases we design, Pdiff decreases while the upstream 0gi decreases or the down- stream 0gi increases. The best result among cases shows Pdiff is reduced by 15.1%.
文摘Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a transpiration cooling thermal protection system was designed and manufactured,and an experiment platform with radiant heating at the bottom as heat source was developed. The cooling capacity of the transpiration cooling TPS was experimentally investigated. By combining transpiration cooling method with traditional TPS,the heat load capability of the TPS can be improved. The structure temperature with active cooling applied was much lower than that without active cooling applied under the same heat load as well as the heat load increased with active cooling than the one without active cooling for the same structure temperature. The experimental results showed that at 5800 s,the temperature of inner structure was 100°C with active cooling applied compared to 500°C without active cooling applied,then the temperature increased and reached to 360°C at 8300 s. Heat load of this transpiration cooling TPS can be increased by over 70% as compared to the passion one and the cooling capability of the transpiration TPS was about 1700 kJ/kg. The results can provide fundamental data for developing the transpiration cooling TPS.
