Investigations of Effects of Surface Temperature and Single Roughness Elements on Boundary-layer Transistion

Résumé du livre

The laminar boundary layer and the position of the transition point were investigated on a heated flat plate. It was found that the Reynolds number of transition decreases as the temperature of the plate is increased. It is shown from simple qualitative analytical considerations that the effect of variable viscosity in the boundary layer due to the temperature difference produces a velocity profile with an inflection point if the wall temperature is higher than the free-stream temperature. This profile is confired by measurements. Furthermore, it is confirmed that even with large deviation from the Blasius condition, the velocity and temperature profiles are very nearly identical, as predictable theoretically for a Prandtl number of the order of 1.0. The instability of inflection-point profiles is discussed.