Experimental investigation of aircraft spray cooling system with different heating surfaces and different additives

•An open loop spray cooling experimental setup with large heating surface and high heating capacity is established.•Four different surfaces are applied in one experiment, considering the influence of both surface area and surface roughness.•Two different solutions with different mass fraction are applied in one experiment.•Suggestions on surface structure and additives are provided for aircraft spray cooling system. As an efficient cooling method for high heat flux, spray cooling has a great application potential on aircraft directed energy weapon cooling. Based on the analysis of previous research results, an experimental system of open loop spray cooling was established. Four different surfaces and two additives were applied and spray cooling performance including surface heat flux, surface temperature and heat transfer coefficient was experimentally investigated with water as the cooling medium. The experimental results indicate that among the four surfaces, drilling surface has the highest heat transfer coefficient and combined surface has the highest cooling efficiency. Meanwhile heat transfer can be enhanced by adding potassium chloride to a certain concentration and then deteriorated with higher concentration; heat transfer is deteriorated with the increase of ethylene glycol concentration. Therefore for aircraft spray cooling system combined surface should be applied for its advantages of low surface temperature and high cooling efficiency while ethylene glycol is preferred to improve the application range of the system in consideration of the corrosion of salt solution.