A Theoretical Study of the Cooling of a Disk by an Impinging Jet of Water

Abstract

Theoretical studies were made to discuss the mechanism of unsteady heat transfer in the system used in the previous experiments, in which a disk of mild steel is cooled at 373K by an impinging jet of water.
Four models were discussed concerning the convective heat transfer in the liquid, those of which are unsteady-state model (A), quasi-steady-state model (B), steady-state and constant heat flux model (C) or constant wall temperature model (D).
First, distributions of temperatures in the fluid and solid, local heat fluxes and local Nusselt numbers at the fluid-solid interface were computed by model A and B. It was found that the results of model A were consistent with those of model B except initial stage of cooling, and that the calculated temperatures in the solid were consistent with observed ones.
Secondly, distributions of temperatures in the solid were computed by model C and D. Model C showed a suitable agreement with calculated ones by model A and B, and observed ones, while model D showed lower temperature than observed ones. From these results, it seemed sufficient to use model C for estimation of temperature in the solid.