Investigation of Combined Transpiration and Opposing Jet Cooling of Sintered Metal Porous Struts

ABSTRACT

Struts are used to inject fuel into the supersonic mainstream of scramjet combustion chambers. The leading edge of the strut experiences the maximum temperature due to tremendous aerodynamic heating. This study describes a combined transpiration and opposing jet cooling system for sintered metal porous struts with a jet flowing out of a micro-slit along the stagnation point line against the incoming flow with methane as the coolant. The combined cooling method for the struts is then compared to cooling by the standard transpiration method. The influences of different slit widths and coolant injection conditions on the strut cooling are numerically investigated. The results show that the combined cooling method significantly reduces the maximum strut temperature. The maximum strut temperature decreases but the coolant consumption increases with increasing micro-slit width. Increasing the micro-slit width more effectively balances the increased cooling effectiveness with the increased coolant flow than just increasing the coolant injection pressure. Coolant injection with non-uniform pressures with higher pressure in the front cavity and lower pressure in the back cavity more effectively enhances the cooling effectiveness and reduces the thermal gradient.

Acknowledgments

This work was supported by a grant from the General Program of the National Natural Science Foundation of China (No. 51276094) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 51621062).

Additional information

Notes on contributors

Gan Huang

Gan Huang is a Ph.D. student in the Department of Thermal Engineering, Tsinghua University, China. He received his B.E. from Huazhong University of Science and Technology in 2013. His main research interests are transpiration cooling and film cooling.

Yin-Hai Zhu

Yin-Hai Zhu is an assistant professor in the Department of Thermal Engineering, Tsinghua University, China. He received his Ph.D. in engineering thermo-physics from Xi'an Jiaotong University in 2009. His main research interests are refrigeration and cryogenics system and spacecraft thermal protection.

Zheng Huang

Zheng Huang is an engineer in China State Shipbuilding Corporation. He received his B.E. from Xi'an Jiaotong University in 2010. He received his Ph.D. from Tsinghua University in 2015. His main research interests are transpiration cooling and film cooling.

Pei-Xue Jiang

Pei-Xue Jiang is a professor in the Department of Thermal Engineering, Tsinghua University, China. He received his Ph.D. in the Department of Thermal Engineering of Moscow Power Engineering Institute in 1991. He then joined the faculty of Tsinghua University and took the professor post in 1997. His main research interests include convection heat transfer in porous media and enhanced heat transfer, convection heat transfer at supercritical pressures, transpiration cooling and film cooling, thermal transport in nanoscale structures, trans-critical CO2 air conditioning systems, and heat pumps. He has published more than 100 papers in international journals and conferences.