Experiments and Modeling of Aviation Fuel Cavitation in a Geometry Relevant to Aircraft Fuel Pumps*

The results of both experiments and modeling of aircraft fuel cavitation are reported. The experiments are performed in a generic geometry that is relevant to that which occurs in aircraft fuel pumps. This involves a radial flow between parallel disks with a 0.4 mm gap between the disks. JP-8 or JP-5 aviation fuel is pumped through the central injection port of the lower disk at a user-selected pressure. The sudden flow turning and associated radial acceleration in the fuel creates extremely low static pressures, resulting in cavitation. This is a situation that often occurs in aircraft fuel systems. The top plate is transparent, which allows for high-speed imaging of the dynamics and extent of the cavitating region. An array of disk static pressure taps allows the radial pressure variation to also be measured. Experimental results are reported for a wide range of fuel injection pressures. A novel spatial Rayleigh-Plesset formulation is used to model the fuel cavitation. The model predictions of the radial location of bubble collapse and the radial pressure profiles are shown to be in excellent agreement with the experiments. This approach will be valuable in the future for predicting and understanding aviation fuel cavitation in other geometries.