The Jet Fuel Hydrodynamic Cavitation Bubble Size with Cavitation Power and Energy from Rayleigh-Plesset Equation 2015-01-2389
Cavitation erosion in aircraft engine and control systems is a major concern in hydrodynamic power units. In developing turbulent flow of low pressure and high velocities, a certain amount of cavitation erosion is not unusual. Cavitation can occur with the presence of fuel vapor or air bubbles dissolved in the fuel tank that are transported through the system. Cavitation erosion is caused by collapse of the bubble, which occurs violently and creates a pressure shock wave of fluid. Striking a solid surface, the shock wave can cause progressive damage if it persists. A kinetic cavitation power rate is developed to make a meaningful estimation of the cavitation erosion rate theoretically, which then can be validated with laboratory experiments. Theoretically, we manipulate parameters such as bubble size, collapse pressure, and energy for a given fuel system design, finding variation within each component of the system. However, cavitation erosion rates vary wildly even when relative developments and comparisons are made. These variations are attributed to the simplicity of governing equations, boundary condition settings, and bubble sizing and geometry assumption differences of given derivation formulations. The jet fuel's bubble size, collapsing pressure, and surrounding fluid pressure, influenced by fuel properties due to temperature variation, appear to be the key factors in cavitation power and energy when predicting component life and degradation of efficiency in engine control systems.