Subsonic flow past localised heating elements in boundary layers

Abstract

The problem of subsonic flow past micro-electro-mechanical-system-type (MEMS-type) heating elements placed on a flat surface, where the MEMS devices have hump-shaped surfaces, is investigated using triple-deck theory. The compressible Navier–Stokes equations supplemented by the energy equation are considered in the limit that the Reynolds number is large. The triple-deck problem is formulated, and the linear and nonlinear analysis and results are presented. The current work is a generalisation of the problem discussed by Koroteev & Lipatov (J. Fluid Mech., vol. 707, 2012, pp. 595–605; Z. Angew. Math. Mech., vol. 77, 2013, pp. 486–493), where the MEMS devices have flat-shaped surfaces. The results show that the hump-shaped heating elements enhance large drops in pressure, and peaks and troughs in the skin friction over the centre of the hump compared with the flat-shaped devices, which may be useful for controlling the flow.