An Experimental Investigation on Transpiration Cooling Based on the Multilaminated Sintered Woven Wire Mesh Structures

Abstract

This paper experimentally investigated a transpiration cooling performance of doublelaminated and triplelaminated sintered woven wire mesh structures with different porosities and arrangements. Each laminated test piece was made up of two or three layers, and each layer has different porosities and same thickness. The porosities of layers include 25.6%, 37.1%, 46.9%, and 55.1%. All the tests were performed with air. The flow rate and temperature of main flow were kept at 300 kg/hr and 90 آ°C, respectively. The blowing ratio between the cooling air and main flow approximately varied from 1.2% to 9%. The average surface temperature of test pieces was captured by an infrared thermal imager. The cooling effectiveness for each specimen was calculated and analyzed. Moreover, the pressure drop of several specimens was analyzed with modified Darcy equation. The results showed that the flow behavior agrees well with the modified Darcy equation. The average porosity of the test piece has a great influence on flow behavior, and the air flow direction through a doublelaminated porous medium has only slight influence on pressure drop in this study. The results also indicated that the cooling efficiency increases as the average porosity increases. The arrangement of layers affects the transpiration cooling performance, and the cooling efficiency of the laminated model is affected by each laminates together.