Computational and experimental investigation of annulus heat transfer with swirl

Abstract

Computational and experimental investigations were conducted to evaluate the effect of swirl on annulus heat transfer. In the computational approach, Reynolds-averaged turbulent Navier-Stokes equations were solved numerically using a standard K-epsilon turbulence model. For the near-wall regions, where accurate velocity and temperature profiles were needed for heat transfer calculations, the equations were solved down to the wall with a fine grid instead of using a wall function. Average convective heat transfer coefficients were measured with heat-flux gauges mounted on a large scale model. Swirl was found to cause a substantial increase in annulus heat transfer. With 45-deg swirl, average heat transfer coefficients on the outer and inner annulus wall were measured 1.5 to 2.5 times those of nonswirling flow. The comparison of the numerical results with the experimental data showed reasonable agreements in nonswirling heat transfer. In swirling flow, the calculated heat transfer agreed well with the measured data on the outer annulus wall, but the calculation overpredicted the inner heat transfer. 44 refs.