Johnson, Eric2024-01-052024-01-052019-12https://hdl.handle.net/11299/259548University of Minnesota M.S.M.E. thesis. December 2019. Major: Mechanical Engineering. Advisor: Alison Hoxie. 1 computer file (PDF); vi, 37 pages.This study investigates the effect of injection gas molar mass on counterflow atomizer performance in terms of droplet Sauter mean diameter (SMD) and relative span factor (RSF). Gas molar mass is found to influence SMD as significantly as gas to liquid mass flow ratio (GLR). RSF is found to depend strictly on SMD, with no additional effect of gas molar mass. A preliminary model for counterflow atomization breakup compares to the collected data with R^2 = 0.976.encountercurrent shearinternal mixingtwin-fluid atomizationvariable densityThesis or Dissertation