Transients in turbulent convective heat transfer to a flow of supercritical helium
Abstract
The features of a turbulent pipe flow with heat transfer from the wall under transient conditions are investigated. A twodimensional flow model is developed with which the velocity profile and the fluid temperature in the tube can be described. Stationary heat transfer to a fully developed flow can also be described with a surface renewal model. This model is extended to be able to describe the transient heat transfer phenomena in case of an arbitrary varying wall temperature. Both models are validated using transient heat transfer measurements in a supercritical helium flow of Bloem. With the twodimensional model the hydrodynamics of the transient flow can be investigated; for the velocity profile, the instantaneous velocity change is shown to be constant over the cross section of the tube. The twodimensional model is shown to be a good tool for predicting both the hydrodynamics in and the heat transfer to a turbulent flow under transient conditions. An application of the model is computed.
 Publication:

Ph.D. Thesis
 Pub Date:
 1990
 Bibcode:
 1990PhDT.........8V
 Keywords:

 Convective Heat Transfer;
 Helium;
 Transient Heating;
 Turbulent Heat Transfer;
 Boundary Layer Flow;
 Flow Velocity;
 Temperature Effects;
 Turbulent Flow;
 Two Dimensional Models;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer