An experimental study on the stability of hypersonic plate boundary layer regulated by a plasma actuation array

Abstract

In this paper, an experimental study on the stability of hypersonic plate boundary layer is carried out using a spanwise plasma actuation array. The characteristics and evolution of different kinds of unstable waves in the hypersonic plate boundary layer are analyzed based on the results of linear stability theory and high-frequency pulsation sensors. The typical morphological characteristics of the boundary layer and the macro-control effect of the plasma actuation array are explored through a high-speed schlieren method. Finally, based on grayscale mode extraction and proper orthogonal decomposition (POD), the influences of three different actuation frequencies on the instability waves and characteristic structure of the boundary layer are studied, including the dominant frequency of the first mode wave, the half-frequency of the dominant frequency of the first mode wave, and the dominant frequency of the second mode wave, the change of characteristic structures under the regulation of plasma actuation is further discussed. The corresponding regulation rules and mechanisms are summarized. The results show that the plasma actuation array can advance the starting position of laminar discontinuities and that the induced coherent structure can excite instabilities at an earlier flow-direction position. The actuation can be used to control the stability of the boundary layer by acting on the first mode wave to break the original unstable wave spectrum characteristics. This verifies the ability of extensional array plasma actuation to regulate the stability of the hypersonic plate boundary layer and suggests it has great potential in the promotion of hypersonic boundary layer transition.

Experimental Study on Hypersonic Double-Wedge Induced Flow Based on Plasma Active Actuation Array

“…In addition, Yang experimented on the stability of the hypersonic plate boundary layer by using a spanwise plasma actuation array. The experimental results verify the ability of extensional array plasma actuation to control the stability of the hypersonic plate boundary layer, suggesting that it has great potential in the promotion of hypersonic boundary layer transition [18]. In addition, a wind tunnel experiment was carried out under the condition of Mach number 6 to study the stability adjustment of the hypersonic blade.…”

“…In the three working conditions, the longest control time was only 90 µs, the energy deposited into the flow field was above 4.1 J, and the repetition frequency was only 1 Hz [16]. However, surface arc plasma actuation shows excellent control effects in supersonic shock wave control, shock wave/boundary layer interaction, and forced supersonic boundary layer transition [17][18][19][20]. Yang conducted controlling hypersonic boundary layer transition using a surface arc plasma actuation array.…”

Thermal rectification in mass-asymmetric one-dimensional anharmonic oscillator lattices with and without a ballistic spacer

“…The better rectification value herein obtained can be ascribed to the added segmented-mass asymmetry, not considered in [49], besides the one in the amplitudes of the onsite potential in both halves of the system. For the case when the ballistic channel is present this result entails the possibility of considering alternative mass distributions for the ballistic channel oscillators to explore possible rectification enhancements, such as the graded mass distribution considered in the harmonic 1D oscillator system of [50], which has been recently applied to the amorphous interface between crystalline Si and Ge leads to manipulate the interfacial thermal conductance of the system [51]. In general, the reduction in TR efficiency for the system with a ballistic spacer seems to have it origin in the increased contribution of the high-frequency phonons in both the spacer and the leads, which entails an increase of the heat flux in the reverse-bias configuration that drastically reduces the rectification efficiency of the device.…”

Thermal rectification in three-dimensional mass-graded anharmonic oscillator lattices

“…For the case when the ballistic channel is present this result entails the possibility of considering alternative mass distributions for the ballistic channel oscillators to explore possible rectification enhancements, such as the graded mass distribution considered in the harmonic 1D oscillator system of Ref. [50], which has been recently applied to the amorphous interface between crystalline Si and Ge leads to manipulate the interfacial thermal conductance of the system [51]. In general, the reduction in TR efficiency for the system with a ballistic spacer seems to have it origin in the increased contribution of the high-frequency phonons in both the spacer and the leads, which entails an increase of the heat flux in the reverse-bias configuration that drastically reduces the rectification efficiency of the device.…”