Effects of Particle-Size and Temperature Difference on Mist Flow over a Heated Circular Cylinder

Abstract

An analytical study is performed to evaluate the surface heat flux and the boundary layer structure over an isothermally heated circular cylinder subjected to evaporating particlevapor flow in forced convection. The governing equations are solved by the local nonsimilarity method and by the Goertler-type series solution. The applicability of both methods is supported by a comparison between the obtained results and with existing solutions for particle-free, single phase flow. Numerical results for the velocity, temperature, and particle size profiles are presented for single component steam-droplets mixture with oncoming velocity 5 m/s at the saturation temperature 100°C. For the number density 5 × 108 numbers/m3 the droplet diameter at free stream is chosen as 10, 30, and 60 μm. For each cases, the wall-to-free stream temperature difference are chosen as 100, 200, and 350 K. Some results are also shown for cases where the free stream droplet diameter is 1, 3 or 5 μm for the fixed value of droplet number density equated 5 × 1011 m−3 and of the wall-to-free stream temperature difference as 100 K. The results show that the enhancement of heat transfer rate is comparatively small in cases where there is large temperature difference but distinctly large in cases involving large particles.