Gradient Heatmetry and PIV Investigation of Heat Transfer and Flow near Circular Cylinders

Abstract

This paper presents an experimental investigation of convective heat transfer around circular cylinders installed one after another. The experimental approach based on the combined application of gradient heatmetry and particle image velocimetry. The method made it possible to measure velocity fields and heat flux simultaneously. Investigation of the flow characteristics and the heat transfer coefficient distribution over a system of cylinders was carried out for various Reynolds numbers in the range of Re = (4…40) × 103. In addition, the distance between the cylinders varied in the experiment. The results showed the the influence of the re-circulation bubble length and the features of vortex formation on the flow pattern and characteristics for the configuration under study in the entire range of regimes. The results were compared with experimental and numerical data from previous literature and found to be in good agreement. Our innovative method based on gradient heatmetry showed high information content and a fairly high accuracy of measurement.