Simulation of cavitation and pressure surge caused by rapid valve closure. An engineering approach

摘要

Prediction of the magnitude of pressure surge in aircraft fuel systems is important from the stand point of designing systems which will not exceed the maximum surge pressure allowed and determining limit pressure so that light-weight systems can be designed, as stated in Gartenberg. Since aircraft refueling systems are relatively low-pressure, the formation of gaseous products, cavitation, introduces severe non-linearity not only in the form of damped pressures but also lower propagation speed. The linear relation between bulk modulus, pressure, and density that exists in high pressure systems is made non-linear by the formation of gases. This paper describes a simulation method for predicting pressure surges in aircraft fuel systems that is suitable for engineering purposes. A model for gas formation has been developed. The dynamic simulation is a relatively fine, one-dimensional, discrete distribution of the fluid solved with MacCormack's predictor corrector technique. The simulation results are compared to actual fuel rig tests. There is a step-by-step description of how the simulation model was tuned to correlate with measured data. Some examples of practical use of the model for actual simulations used for fuel system design are included.