Receptivity Study of Hypersonic Boundary Layer under Freestream Finite Amplitude Continuous Entropy Disturbance with Single Frequency

Abstract

The DNS method is used to calculate the unsteady flowfield around blunt cone under the action of a single frequency finite amplitude continuous entropy wave. The hypersonic flowfield response to single frequency finite amplitude entropy wave is investigated, and the hypersonic boundary layer receptivity features under single frequency finite amplitude disturbance are explored. The results find that the strong disturbance wave is produced by the interaction of freestream wave with shock wave and boundary layer, and there are regular high-entropy and low-entropy regions in the downstream evolution process. The frequency characteristics of boundary layer disturbance wave are directly related to freestream disturbance wave, and the frequency characteristics become weaker as the disturbance wave evolves downstream. During the development of disturbance downstream, the second, third and fourth (f2-f4) order modes in the boundary layer increase relatively. The central disturbance modes of the nose region are the fundamental mode in the boundary layer, and the main disturbance modes in the boundary layer of the downstream region of the flowfield are composed of the fundamental mode (f1) and the second, third and fourth (f2-f4) order modes.