Undergraduate Research: The effects of buoyancy on droplet evaporation for spray combustion systems

Many studies on spray combustion systems have been performed in the International Space Station, which creates a microgravity environment. These studies are used to investigate the fundamental burning phenomena of fuels, which provides useful information to certify renewable fuels such as bio-derived jet fuels. However, aerospace spray combustion systems are placed under conditions where gravity plays a major role. Droplets in real-world systems undergo a multitude of convective effects, specifically natural and forced convection. This undergraduate study investigates the influence that gravitational effects, such as buoyancy, have on the evaporation behaviour of fuel droplets within aviation spray combustion systems.

This work builds upon previous work from Setiya, Palmore, and Xu [AIAA SciTech, 2024]. This undergraduate study utilizes an interface capturing numerical simulation with the volume of fluid method to solve for evaporating and boiling flows. To simulate the buoyancy-driven flow, the density of gas and liquid phases are changed due to the Boussinesq approximation as an equation of state, and tied to the incompressible flow solver. The goal of the project is to further understand the effects of buoyancy on an evaporation process, and to investigate the effectiveness of the simplistic modeling approach (Boussinesq) in predicting combustion properties. Data from simulations of droplets are demonstrated under various conditions and are validated against experimental data.