Turbulent Near Wake of a Flat Plate : Part 3, Effect of Pressure Gradients

Abstract

The turbulent near wakes starting from the turbulent boundary layers on both sides of a flat plate and subjected to pressure gradients have been investigated. The experiments have been conducted in zero, adverse, favourable and mixed pressure gradients, and the results show that the total pressure along a streamline of the near wake in a pressure gradient changes at a rate nearly equal to that along the same streamline in zero pressure gradient, which suggests that the transverse gradients of Reynolds stress are little affected by pressure gradients in the turbulent near wakes. On the basis of the experimental results a model to predict the development of a near wake in a pressure gradient has been presented. The calculated results agree well with the experimental data except for a strong adverse pressure gradient case.