Experimental Validation of Methods Providing Boundary Conditions to Simulate the Evaporation Process of Water Injected Into High Speed Air Flow

Abstract

Water injection into a high speed air flow has been recently investigated by many scientists and is still an important field of research in gas turbine technology. To study the behavior of droplets in gas turbines, expensive experimental tests and their validation with analytical and Computational Fluid Dynamics (CFD) models are necessary. The Euler-Lagrange approach can be used to tackle these problems due to their capability in tracking particles along the domain, relative ease in formulating and applying them to the current industrial problems in terms of acceptable computational cost. However, providing spray boundary conditions using Euler-Lagrange approach is quite challenging because the spray pattern depends upon various parameters like spray angle, velocity, diameter distribution etc. In this paper, to obtain these parameters, two different approaches are described. The first approach depends on an analytical model for velocity and spray angle injection conditions and the second approach depends on an Euler free surface simulation. For diameter distribution, Rosin Rammler distribution function and experimental data are used. When combined together these lead to four particle injection conditions. The results achieved from all the four cases are compared with the experimental data of water droplet evaporation in a high speed air flow obtained from a hot air test rig operating at conditions of real gas turbines.