Study of Rain Simulation for Aircraft Engine Certification

Abstract

Engine tests under flight conditions are extremely important at the stage of its complex debugging. These conditions include the simulation of icing, check for the penetration of birds in the inlet vanes, modeling hail and rain. Simulation of rain due to its significant unsteadiness need providing requirements for the concentration of water in the air, the distribution spectrum of droplets by size, the value of the average diameter of the droplets, the mass flow rate curves for the injectors and the conditions of interaction of droplets with air. This paper contains information about the developed method of calculating the characteristics of the injector for the necessary modes of water injection into the engine as well as experimental study of the injector and conducted studies of the parameters of its operation process, including the choice of optimal modes. As a result of the research, an injector was developed that allows to obtain the average median diameter of 2.66 mm and droplets of the certification spectrum. Also there was worked out the schematic diagram of the collector module of the installation for rain simulation that meets the certification requirements: simulation of rain in the “idle power” and “take-off” modes with the condition of simultaneous provision of water concentration in the air of 20 g/m3 and the average median diameter of 2.66 mm. This installation provides operation in transient modes with the condition of maintaining the water concentration in the air of 20 g/m3.