Effect of Jet Position and Shaft Obstruction on Impingement Cooling of Rotating Bodies

Abstract

The purpose of this investigation was to determine the effect of jet radial position and shaft obstruction on the convective heat transfer from rotating disks cooled by a single jet of impinging oil. The temperature of the disk was maintained as near as possible to the temperature of the oil jet to minimize property variations in the oil layer flowing over the disk. In order to investigate the effect of the jet radial position on the convective heat transfer, the data were taken for different jet positions including the disk center and various radial positions on the disk. In the case of shaft obstruction effect, the jet position was fixed at a radial position greater than the largest radius of the dummy shafts used in the experiments.

The investigation was made over a range of disk rotational speeds, jet flowrates, jet temperatures, jet diameters, disk diameters, jet radial positions and dummy shaft diameters. A correlation of the data is nondimensional Nusselt number which was given as a functional of rotational Reynolds number, Re^r, jet Reynolds number, Re^j , jet Prandtl number, Pr , normalized jet radial position, r/R, and normalized dummy shaft area, A^_s/A.

The parameter ranges are: 15,000 <= Re^r < 500,000 200 <= Re^j < 1,300 87 <= Pr <= 400 0.0 <=r/R <= 0. 8 0.09 <= A^s/A <= 0.25