Heat Transfer in a Rotating Cavity With a Peripheral Inflow and Outflow of Cooling Air

Abstract

This paper describes a combined computational and experimental study of the heat transfer in a rotating cavity with a peripheral inflow and outflow of cooling air for a range of rotational speeds and flow rates. Measurements are made in a purpose-built rig, with one of the two rotating discs heated, and computations are conducted using an axisymmetric elliptic solver incorporating the Launder-Sharma low-Reynolds-number k–ε turbulence model. Measured values of the tangential component of velocity, Vπ, exhibit Rankine-vortex behaviour which is not accurately modelled by the computations. Both computed and measured values of the radial component of velocity, Vr, confirm the recirculating nature of the flow. In the outflow region, agreement between computed and measured values of Vr is mainly good, but in the inflow region the computations exhibit a “peaky” distribution which is not shown by the measurements. The measured and computed Nusselt numbers show that Nu increases as the magnitudes of the flow rate and the rotational speed increase. The computed Nusselt numbers (allowing for the effects of conduction through and radiation to the unheated disk) reproduce the measured trends but tend to underestimate the experimental values at the larger radii.