Modeling and experimental characterization of aviation fuel cavitation in the radial flow between two parallel disks

We report on the results of our modeling and experimental characterization efforts of cavitation in the radial flow of aviation fuel JP-5 and distilled water between two parallel disks with a thin gap, which is a highly relevant geometry to aviation fuel pumps. A spatial Rayleigh-Plesset equation was first adapted to predict the radial location of cavitation cloud collapse. We then incorporated the spatial Rayleigh-Plesset equation into the barotropic model and generalized it to a radial flow geometry to estimate the radial pressure profiles. High-speed imaging and pressure measurements were used to quantify the cavitation behavior and capture the radial collapse location of cavitation voids for different flow regimes to validate our model. The model predictions of the radial location of bubble collapse and the radial pressure profiles were shown to be in excellent agreement with the experiments. In addition, an enhanced gradient shadowgraphy technique that we employed on the high-speed imaging data revealed an unsteady shock wave presence, propagating in a spiral motion in the JP-5 fuel. In contrast, a standing bubbly shock is observed in water. Our modeling approach can be utilized for predicting aviation fuel cavitation erosion damage without the expense of time-costly high-fidelity simulations.