A High Order Cut-Cell Method for Numerical Simulation of Hypersonic-Boundary Transition with Arbitrary Surface Roughness

Abstract

Hypersonic boundary-layer transition can be affected significantly by surface roughness. Many important mechanisms which involve transition induced by arbitrary roughness are not well understood. In this paper, we propose a new high-order cut cell method which combined the non-uniform finite difference method for discrete points near the curvilinear boundary and shock-fitting method for the bow shock. The receptivity process induced by interaction of Mach 5.92 flow over flat plate under the combination effect of twodimensional surface roughness and blow-suction is investigated. Both steady state solutions and unsteady solutions have been obtained by using the new method. For steady flow with roughness, there is significant change inside the boundary layer with flow separation before and after the roughness element. For unsteady flow, the results for flow instability induced by both blow-suction slot and roughness are obtained and analyzed by Linear Stability Theory (LST). These results show that the roughness element with height to be half the boundary layer thickness may delay the hypersonic transition.

Second Mode Suppression in Hypersonic Boundary Layer by Roughness: Design and Experiments

“…Since 2009, for the purpose of simulating hypersonic flow with finite height roughness elements, Duan et al has developed a highorder cut-cell method [14]. The new method was then applied to simulating finite roughness elements in a hypersonic boundary layer at Mach 5.92 [7,14].…”

“…The new method was then applied to simulating finite roughness elements in a hypersonic boundary layer at Mach 5.92 [7,14]. Different from the wavy wall idea, as in [5] and [10], they found that the relative location of the 2-D roughness element and the synchronization location plays an important role [7].…”

“…More detail about the synchronization location can be found in [15,16]. Zhong's group argues that 2-D roughness elements can damp 2-D disturbances if the roughness element, with a height less than the local boundary-layer thickness, is downstream of the synchronization point [14]. This finding has motivated a series of parametric studies on roughness effects including roughness locations, heights, and widths by Fong et al [17][18][19].…”

Stabilization of hypersonic boundary layer waves using 2-D surface roughness

“…Since 2009, for the purpose of simulating hypersonic flow with finite height roughness element, Zhong's group at UCLA has developed a high-order cut-cell method [23]. The new method was then applied to simulating a finite roughness elements on a hypersonic boundary layer at Mach 5.92 [16,23].…”

Study on Stabilization and Destabilization Effect of a Smooth Hump in Hypersonic Boundary Layers by PSE

“…It is natural that influence of roughness on the convective instability of mode S need to be examined first to investigate the cause of delaying transition. Duan et al 4,5 and Fong et al 6 investigated roughness effect on instability of mode S by using direct numerical simulations (DNS). Their DNS studies showed that the roughness located at the downstream of synchronization point can stabilize mode S. Although they imposed mode S at the inflow boundary and focused on its downstream evolution, it is possible in DNS study that the other mechanisms other than the convective instability of mode S can be involved due to roughness.…”