Numerical investigation of horizontal flow film boiling of saturated liquid over two inline cylinders in the mixed convection regime

Abstract

Mixed convection film boiling in a system of two cylinders positioned in an in-line configuration is numerically studied. The relative importance of inertia over buoyancy is given by Froude number. The direction of the incoming saturated liquid is perpendicular to the direction of gravity. Simulations are performed for the Reynolds number values of 50, 100, and 150; non-dimensional wall superheat values of 0.3, 0.6, and 0.9; and non-dimensional spacing between cylinders values of 2.0, 4.0, and 6.0. Three modes of vortex shedding from the cylinders are identified. An increase in the Reynolds number increases the heat transfer for the upstream cylinder and decreases heat transfer for the downstream cylinder. Increasing the non-dimensional wall superheat leads to decrease in the heat transfer rate from both the cylinders. Changing the non-dimensional spacing between the cylinders does not significantly alter the heat transfer from the upstream cylinder. However, heat transfer rate from the downstream cylinder increases significantly with increase in the non-dimensional spacing between the cylinders. The dynamic interface is affected by the shear layer instability and the vortex shedding pattern, which in turn affects the vapor film thickness around the cylinders and the rates of heat transfer from the cylinders.