Temperature and velocity distribution in the wake of a heated cylinder

Abstract

Detailed measurements of the temperature and velocity distribution in the two-dimensional wake of a heated cylinder are presented. Measurements of the temperature distribution on the surface of the cylinder for various rates of heat dissipation are also included, and these data are correlated in the form of dimensionless parameters. The cylinder was 12.15 inches long and 0.190 inch in outside diameter and was placed midway between the upper and lower parallel walls of a horizontal conduit of rectangular cross section through which air flowed normal to the cylinder. The walls, which were spaced 0.75 inch apart, were independently maintained at desired temperatures. In one series of measurements of the temperature and velocity distribution in the wake the rate of heat dissipation from the cylinder was maintained at a constant value of 5.42 watts per inch length of the cylinder for Reynolds numbers of 4,270, 7,630, 15,200, and 26,900 based on the free cross-section area of the conduit. In another series of measurements at a Reynolds number of 15,200 the rate of heat dissipation from the cylinder was maintained at 1.70 watts per inch and 3.20 watts per inch. In each of the above cases the temperature of the walls of the conduit was maintained at 100[degrees]F, identical to the bulk temperature of the entering air. In addition measurements at a Reynolds number of 15,200 were made with the entering air at a temperature of 100[degrees]F, the upper wall at 130[degrees]F, the lower wall at 70[degrees]F, and a rate heat dissipation of about 5.43 watts per inch. Point values of temperature and velocity were obtained as a function of position in the wake of the cylinder. From these data values of eddy conductivity and eddy viscosity were calculated. Analysis of the data on the basis of Prandtl's momentum transfer theory and Taylor's vorticity transfer theory is included. The results are given in tabular form, and a number of graphical presentations of the data are included.