UNIFORM AIR INJECTION INTO A TURBULENT BOUNDARY LAYER FLOW OVER AN AXIAL CIRCULAR CYLINDER
MINNESOTA UNIV MINNEAPOLIS HEAT TRANSFER LAB
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An experimental study was made of the effects of uniform air injection into the turbulent boundary layer flowing on an axial circular cylinder with a nominal free stream velocity of 120 feet per second. The blowing rate parameter divided by the free stream flow rate varied from 0 to 0. 00021 while the Reynolds number based on free stream conditions varied from 400, 000 to 1,060,000. The data for velocity profiles were inserted into the momentum equation and the distribution of turbulent shear stress and eddy viscosity was obtained. The correlation of eddy viscosity with both Reynolds number and injection rate was obtained by dividing by the product of the maximum shear stress velocity and boundary layer thickness. Furthermore, the results for the universal velocity profile correlate better when the maximum shear stress velocity is used rather than wall shear stress velocity. When some of the results are compared with previous experiments, the use of the maximum friction factor rather than wall friction factor in the blowing rate parameter produces better correlation between these various experiments.
- Theoretical Mathematics