An experimental investigation on transpiration cooling of a nose cone model with a gradient porosity layout

• Published in: Experimental thermal and fluid science Vol. 106; pp. 194 - 201
• Main Authors: Wu, Nan, Wang, Jianhua, He, Fei, Dong, Guangqi, Tang, Longsheng
• Format: Journal Article
• Language: English
• Published: Philadelphia Elsevier Inc 01.09.2019; Elsevier Science Ltd
• Subjects: Coolant mediums; Cooling; Cooling effects; Cooling performances; Flow rates; Heat flux; Layouts; Mass flow rate; Nose; Nose cones; Porosity; Porosity layout; Porous media; Stagnation; Sweat cooling; Transpiration; Transpiration cooling; Water; Porosity layout; Transpiration cooling; Coolant mediums; Cooling performances
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2019.05.002

•A nose cone model with a gradient porosity layout is manufactured.•The transpiration cooling performances are experimentally investigated in depth.•The influences of porosity layout and coolant mediums are discussed.•A numerical approach to estimate coolant mass flow rate is introduced. The optimal design of porosity layout within the porous matrix to enhance stagnation-point cooling effect and reduce coolant load is one of the key topics in the research field of transpiration cooling. This paper presents an experimental investigation on the effect of porosity layout and coolant mediums on the transpiration cooling performances. Two nose cone specimens were manufactured and used, one is named as “uniform porosity layout (UPL)”, and the other is “gradient porosity layout (GPL)”, where the porosity is locally enlarged near the leading edge. In compared with UPL, GPL is better in utilizing coolant, and the required coolant injection pressure is reduced. For GPL, the influence of coolant mediums (i.e. cooling air and liquid water) is further discussed, and two different cooling behaviors are observed. For GPL/liquid water, with the increase of coolant mass flow ratio, there is a transition from gas-like cooling behavior to liquid-like behavior. Besides, a numerical estimation of maximum heat flux on the nose cone and the required coolant mass flow rate is analyzed.