On the displacement in origin for turbulent boundary layers subjected to sudden changes in wall temperature and roughness

The present work studies the behavior of flows that develop over surfaces that present a sudden change in surface temperature and roughness. A particular interest of this study is to investigate any existing relationship between the error in origin for both the velocity and the temperature profiles, so that any analogy between the logarithmic laws for the velocity and the temperature profiles can be assessed. Three different types of surfaces are considered and the flow is made to pass from a cold smooth surface to a hot rough surface. Measurements are presented for the mean velocity and temperature profiles.