渦後流内の衝撃波

抄録

The density gradient is, in some cases, observed near the body surface when a pair of vortices in vortex wake, which develops behind vehicle flying in supersonic speed with incidences, is still stable and their strength is enough strong. The purpose of this paper is to examine the mechanism responsible for the generation of this density gradient and to find out it's characteristics. The systematic experiments including pitot tube traverse and schlieren photographing are conducted and further the computational simulation of the flow field are carried out, the flow model of which is two dimensional jet impingement. Their results are readjusted as follows.
1. There is an entropy jump across this density gradient.
2. The flow field caused by interaction between the boundary layer and this density gradient turning down by other shock wave is similar to that of shock-boundary layer interaction.
3. The position of shock wave obtained by computational simulation is almost coincident with that of this density gradient observed on the schlieren photographs.
On the base of the reasons above mentioned, it is confirmed that this density gradient is shock wave, which is produced by blowdown of a pair of vortices. And if there are stable vortices being enough strong and their space is favorable, it is concluded that this shock wave is surely observed near the body surface in vortex wake even in the cases of wider range of Mach number and more complicated body shapes.