Detecting 3-D, turbulent separation regions using unsteady, computerized thermographic technique

An unsteady, computerized thermographic technique (CTT) was implemented as a nonintrusive tool to detect flow separation regions in incompressible, low-Reynolds-number, turbulent three-dimensional (3-D) flows. The basic idea of this technique is to take advantage of the dependence of the heat transfer coefficient on the flow conditions on the body surface. The experimental equipment and the related test procedure are illustrated. The problem of identifying flow separation regions through thermographic data elaboration is considered, and an application of the method, to the detection of flow separation regions is described with reference to a bluff cylinder in axisymmetric flow and a hemisphere cylinder both in axisymmetric and 3-D flow