Effect of roughness element height of blunt wedge structure on the hypersonic flow field

To study the effect of isolated wall roughness element height on the hypersonic blunt wedge flow field, the hypersonic blunt wedge flow field under the condition of wall roughness element is numerically simulated by using high-order precision finite difference method, the influence of isolated wall roughness element height on the flow field and boundary layer flow is analyzed, and the influence of isolated wall roughness element on wall pressure, wall friction resistance and wall heat flow is studied. The results show that the raise of roughness elements height will result in the increase of the intensity of compression wave and expansion wave, the position of compression wave and expansion wave will move upwards and the influence range will be extended. The augment of the height of roughness elements accelerates the change of flow parameters in the boundary layer and increases the maximum value, and the heating effect of incoming flow on the first half of the roughness element increases and the minimum value of flow parameters decreases. When the height is greater than 0.1, the leading edge of the roughness element will form a vortex, and the vortex will expand with the increase of the roughness element, which will inhibit the heating of the leading edge of the roughness element by the incoming flow. But the wall heat flux, From the first inflection point to the center of the roughness element, will increase significantly with the increase of the roughness element height.