Experimental investigation of the influence of the passive porous coating on laminar-turbulent transition of the hypersonic boundary layer of the sharp cone at angles of attack

Sergey Morozov,Sergey Lukashevich,Alexander Shiplyuk,S.V Alekseenko

doi:10.1051/matecconf/201711502009

Abstract

The problem of the delaying laminar to turbulent transition by the passive porous coating on the sharp cone at the angle of attack has been studied for the first time. Experiments are conducted in a Transit-M hypersonic short-duration wind tunnel at the Mach number 5.9. The boundary layer laminar-turbulent transition is determined by heat flux distribution on the surface of the cone. It is found that the transition on the porous surface in compare to smooth surface has been delaying on the windward side at the 0.5°, 1° and on leeward side at the 0.5°. There is no effect of the porous coating on the location of the laminar to turbulent transition at angle of attack 1°.

Highlights

Research of hypersonic boundary layers stabilization metods are an important problem of the hight speed aerodynamic due to the significant increase of the surface heat flux of the turbulent boundary layer in compare to the laminar boundary layer
The heat flux distribution deviations from linear law in log scales at x ≈ 100 mm indicates the onset laminar to turbulent transition
The end point of the transition xtr = 258 mm is determined at the location of the maximum of the heat flux distribution

Summary

Introduction

Research of hypersonic boundary layers stabilization metods are an important problem of the hight speed aerodynamic due to the significant increase of the surface heat flux of the turbulent boundary layer in compare to the laminar boundary layer. On the passive porous coating with microstructure second mode disturbances grows slower than on the smooth surface [2]. The ability to delay transition by passive porous coatings are shown in several works [2 - 4]. The previous experimental studies are shown that it’s possible either to reduce or magnify the energy of second mode disturbances using the porous coating with different length on the cone [11]. It indicates that the ability of the porous coating to delay transition is not predictable in case of small varying hypersonic boundary layer parameters. The stability of the second mode disturbances strongly depends on bluntness of the leading edge [6, 7, Ошибка! Источник ссылки не найден.] and angle of attack [9, 10]

Methods

Results

Conclusion