Model of the filling of an automotive fuel tank

One of the problems associated with automotive fuel tanks is premature shut-off during the filling process. This occurs when the fuel dispensing nozzle shuts off before the fuel tank is completely filled. rehensive but simplified lumped parameter model has been developed to determine the pressure and flow rate associated with the automotive fuel tank for the purpose of predicting premature shut-off. Unlike previous work, this model includes the entire fuel system, including a closed rectangular tank with a filler tube, rollover valve, and vent tube that connects the filler tube to the tank. The system was divided into several control volumes and connecting valves. Continuity equations were written for each of the control volumes and energy equations were written for each of the connecting valves. The model includes the effects of the fuel tank system geometry, fuel nozzle dispensing rate, fuel volatility, multiphase, multicomponent flow through the filler tube, air/fuel vapour in the tank dome, vapour generation and choking in the vent tube, and the rollover valve due to the low speed of sound of the vapour droplet flow. athematical model consists of five nonlinear, integral equations and a number of algebraic equations. A commercial numerical solver (Simulink) was used to solve these equations subject to appropriate boundary conditions. mplified model was used to generate results to compare with existing experimental results. In spite of its simplicity, it was capable of predicting the nature of the shut-off for all of the corresponding sets of experimental data. Prediction of the magnitudes of the tank dome pressure and the filler tube pressure were, however, only in fair agreement with the experimental values. The model was also used to perform a sensitivity analysis of model parameters. The results were found to be most sensitive to vent area around the filler nozzle, liquid dispensing flowrate, and fuel volatility.