Spray in Crossflow

Dr. Anubhav Sinha, University of Warwick Cambridge Fluids Network - fluids-related seminars 27 April 2018 1:00pm JDB Seminar Room, CUED My research focuses on the investigation of fuel injection in crossflow, having potential application in gas turbine combustors. The first part of this study deals with liquid jet in crossflow. The effect of nozzle geometry on jet breakup and trajectory are investigated. Surface waves on liquid jets are observed and a theoretical framework is developed to predict the wavelength of these waves. Airblast spray in crossflow is then studied and its structure, trajectory, droplet size distribution and droplet velocities are characterized for various operating parameters. Different spray regimes are observed and a regime map is proposed. Spray from Jet-A1 and its surrogate fuels are studied in preheated cross flow. Evaporation of droplets is studied and evaporation constants are calculated. The last part of the study is concerned with numerical simulation of the above mentioned experimental studies. Assuming droplets to be perfect spheres at injection is a very common assumption in spray simulations. Near-nozzle images captured in this study show highly distorted droplets/ ligaments which limits the applicability of spherical droplet assumption. Modification in the droplet break-up model is proposed to account for the initial droplet distortion. Finally, I will talk about the ongoing research on hydrogen explosions in vented enclosures. A new phenomenological model, based on spherical flame propagation is developed which is found to be in good agreement with the experimental data.