Simultaneous Measurement of Velocity and Temperature Downstream of a Heated Cylinder

Bluff bodies placed in a flow, such as electrical transmission lines, cartridge heaters, pipes of heat exchangers, factory chimneys and so on, often have a different temperature compared to that of the surroundings. The structure of the flow developing around bluff bodies has been investigated for a long time (Adrian, 1991; Williamson, 1996). The Ka´rma´n vortex street was and is examined by numerous researchers, both experimentally and numerically. Nevertheless, the question arises as to how this vortex street is modified by a heated cylindrical bluff body. What is the influence of heating on the frequency of the detaching vortices, the structure of the vortices and the location of the detachment? Many of these questions have already been answered by the help of numerical simulations and of measured velocity distribution using Particle Image Velocimetry (PIV) and the vortex distributions obtained from this (Venkatakrishnan and Meier, 2004). A further question is the heat loss caused by the vortex structure and the forced convection. To tackle this question, the Background Oriented Schlieren (BOS) method is applied here. At the same time, first steps have been taken towards determining temperature and vortex distributions simultaneously, which are introduced in this paper. Main objective and novelty of this work is the solution for the mentioned measurement problem with a single camera.