Design And Optimization Of Stamping And Ejecting Device For Air Cooling System Of Aircraft

The air cooling system of the aircraft can dissipate the heat in the cabin in time and provide the suitable working temperature environment for the airborne electronic equipment.In order to provide more ram air mass flow for the cooling of aircraft electronic equipment,design and optimization of stamping and ejecting device for air cooling system of aircraft is carried out.First,the ejector is designed and optimized preliminarily by theoretical analysis and numerical calculation,and the ejector suitable for the ram air inlet duct is obtained.Second,the existing ram air inlet duct is optimized,and the ram air inlet duct is modified according to the structure and installation position of the ejector.Finally,the optimized ejector and ram air inlet duct is combined with each other,and the ram air inlet duct with ejector is obtained.Finally,through the numerical analysis of the airframe flow field,the opening position of the ram air inlet duct is obtained.In order to get the working performance of the ram air inlet duct with ejector,the numerical calculation of the ram air inlet duct with and without ejector at different heights and different Maher numbers is carried out,the results are described as follows:(1)At low height and low speed,the installation of ejector in the ram air inlet duct can effectively improve the cold air mass flow in the inlet duct.In particular,when the flight height is 5km and the flight Mach number is 0.2,the increase of the mass flow rate in the inlet duct is 96.87%.(2)When at the same height,the increase of the mass flow rate decreases with the increase of the Mach number after the ejector is installed.When the number of flight Mach increases to transonic speed,the ejector increases the resistance in the ram air inlet duct and the mass flow rate of the cold air slightly decreases due to the variation of the working mode of the ejector(The reduction is about 3.89%~11.64%).(3)Through the numerical simulation of the ram air inlet duct with ejector under different working conditions,it is found that the increase of mass flow rate of the ram air inlet duct with ejector is higher when the altitude is 10 km than that of the height of 5 km.