Transpiration cooling of surface by nearwall two-phase Co-current jet

摘要

The mixing of a hot flow with a coaxial gas-droplet flow in a cylindrical channel is investigated experimentally. The main flow velocity in experiments was≈45 m/s and its temperature was≈50; 100; 150℃. The weight concentration of sprayed liquid in the near-wall flow was equal to 0; 5; 10%.Visual observations, results of the flow temperature measurements over cross-sections and at the wall along the channel proved the existence of liquid precipitation on the wall. A significant increase of the protection quality of two-phase cooling isfound at liquid concentrations less than 5%. For concentrations higher than 5% there is little change, the efficiency of two-phase film cooling decreases with an increase of the main flow temperature.