The Natural Convection of Air Over a Heated Plate With Forward-Facing Step

Abstract

An experimental study of free convection flow of air over a vertically oriented, isothermal, heated plate with a forward-facing step was done. The step height was varied from 0.3175 to 0.9525 cm, and the distance of the step from the leading edge was varied from 7.62 to 15.24 cm. Temperature profiles were measured with a thermocouple probe, and velocity profiles were measured by photographing the trajectories of small dust particles carried along with the flow. For comparison purposes the same measurements were made for a flat plate. The results are nondimensionalized for comparison with the theoretical velocity and temperature profiles for a flat plate. A discussion of how the temperature and velocity profiles deform as the fluid passes over the step and the effect of step size and location on profile shape is included. The experimentally obtained temperature profiles are used to calculate the dimensionless heat-transfer coefficient. This coefficient is characterized in terms of the size and location of the step.