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
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%.
