FRICTION AND HEAT EXCHANGE IN A TURBULENT BOUNDARY LAYER ON A POROUS SURFACE DURING INJECTION OF DROP-FORMING LIQUIDS AND GASES,
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
Pagination or Media Count:
Air friction and heat-transfer relations were studied for a stream of evaporating liquid or gas passing through a porous wall and functioning as coolant while the air supplying the heat passes along the wall in turbulent flow. A Cu plate with 35 porosity was used as a model of the porous wall. Water, EtOH, and glycerol were used as evaporating liquids. The coolant gases were He, air, Ar, Freon-12, and Freon-12-air mixtures, the molecular weight of the coolant gases varying from 4 to 121. To determine the friction coefficients, a nonporous plate was subjected to the air flow at temperatures and Reynolds numbers corresponding to those at which the coolant was blown in. The effect of cooling with water and EtOH on the average values of the dimensionless heat-transfer coefficients was determined at desired thermal parameters of injection.
- Fluid Mechanics