Abstract:
To investigate the influence of wall temperature control on flat-plate laminar flow boundary layer and turbulent flow boundary layer, and to explore the influence law of temperature control on flat-plate transition Reynolds and wall frictional resistance, wall temperature control is carried out on flat plate flow boundary with zero pressure gradient. Flat plate boundary-layer flow is simulated numerically using a three-equal turbulent model with transition model, and influence of wall temperature control on wall friction drag coefficient, boundary layer transition and turbulent boundary layer is considered mainly. Numerical results indicate that boundary-layer transition Reynolds number has increased by almost 36%, and the wall friction drag has decreased by almost 9.6% when increasing wall temperature to 432 K from 288 K. The research shows that with wall heating, air's viscous effect in the temperature boundary layer of laminar flow, is enhanced, Reynolds shear stress and turbulent kinetic decreased, and the flow is more stabilized; and in the viscous sublayer of turbulent flow, velocity gradient and viscous shear stress decreased, then wall's friction shear stress is minished. Therefore, boundary-layer transition could be delayed, and friction drag coefficient of turbulent zone and friction drag of flat plate could be reduced by wall heating control.