Heat Transfer by Steady Streaming in a Horizontal Annulus with Inner Heating at Boundary Vibration

Abstract

Convection and heat transfer are studied experimentally in a horizontal annulus, the outer wall of which is formed by an elastic silicone tube, and the inner one – by a copper cylindrical heat exchanger. The working volume is filled with a viscous fluid. T he temperature of the outer boundary is kept constant. At the inner boundary, a constant heat generation power is maintained. The elastic outer wall is driven in a periodic motion by two linear motors, installed symmetrically to the left and to the right of the container and performing synchronous oscillations. Thermal measurements are carried out at steady state temperature. In the absence of vibrations, free convection is observed. Vibrations lead to the generation of steady averaged flows in the form of a system of eight pairs of rolls, parallel to the cylinder axis. Vibrational convection enhances heat transfer across the annulus. The structure of steady flows and the rate of heat transfer are determined by the interaction between two convective mechanisms.