Development of a Quantification Methodology for Slosh Noise Associated with Dynamic Fuel Flow Behavior in Passenger Car Tank

Fuel slosh noise has been important criteria in designing the fuel tank. Since the car manufacturers have tried to measure and reduce slosh noise of fuel tank, a requirement of direct quantification methods is felt. This paper presents a methodology to quantify the slosh noise in passenger car at various fuel level conditions. With enhanced awareness and demand for fuel efficient cars, weight reduction has become important that has led to move from steel tanks to plastic tanks. Also “Baffles” have been used for many years in fuel tanks to reduce the effect of the fuel sloshing that is additional weight in the tanks [1].

To evaluate the slosh performance of plastic tanks, study has been carried out to predict the dynamic behavior of the fuel inside a fuel tank during transient driving conditions, using a commercial CFD (Computational Fluid Dynamic) code Star CCM+. Free surface and broad band noise source models are used to estimate the turbulent noise generated in the fuel tank with respect to flow pattern of fuel inside tanks. The experimental study is carried out in actual vehicle, where the dynamic behavior of the fuel tank was understood by measuring the acceleration data on fuel tank along with sloshing noise during typical driving pattern and also at different fuel level inside tank. The above pattern is simulated in the CFD using the inputs from actual testing and flow pressure distribution is analyzed. Hence the methodology is developed based upon the observation and learning is applied to design the new fuel tank with better sloshing. Using this study further during new model development, weight reduction was achieved without hampering the slosh noise phenomenon.