Influence of Thermal Conditions on Accelerated Boundary Layer Subjected to a Wall Heating

摘要

The investigation reports on numerical simulation of a laminar near-wall flow subjected simultaneously to a favorable pressure gradient and wall heating at constant temperature or at constant heat flux. The analysis of laminar boundary layer equations showed that an important feature of such boundary layer is an overshoot of the longitudinal velocity profile, when the velocity within boundary layer becomes greater than the velocity in the main flow. It is shown that namely simultaneous action of wall heating and acceleration leads to appearance of the overshoot. Overshoot is the reason of increasing of skin-friction coefficient and Stanton number. In addition, it leads to a negative momentum thickness. However, the kind of the thermal boundary conditions at the wall has an appreciable influence on some flow parameters. It can be explained by the behavior of the maximum velocity.