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With the reduction of noise from the engine, road-tyre interaction, power train, etc., noise from other sources has become noticeable to the passengers and causing annoyance. Sloshing in fuel tanks is a source of such noise in the hybrid vehicle. It is predominant during acceleration and braking conditions. Sloshing noise generation is a multi-physics phenomenon involving fluid mechanics, structural dynamics and acoustics. Sloshing noise occurs when the fluid in a partially filled tank interacts with surrounding structures when the tank is subjected to external excitations. Based on the type of fluid interaction with structure, sloshing noise is classified into Hit, Splash and Clonk noises. Hit noise is a structure-borne noise while, splash and clonk are air-borne noises. Hit noise is predominant in the non-planar sloshing regime, where as in chaotic regime splashing also occurs. Baffles are proved to be a good solution to control the sloshing in a partially filled tank. However, the effect of baffles on the sloshing noise and its generation mechanisms is yet to be understood properly. This paper presents a multi-physics approach to predict the hit noise in a rectangular tank with baffle. The conditions for the predominant occurrence of hit noise are created by applying the longitudinal periodic excitation to the tank. Numerical analysis of the fluid flow using computational fluid dynamic (CFD) model and transient structural analysis using finite element model of the tank are performed in a weakly coupled manner. Parameters like dynamic pressure and vibration displacement as a function of time are monitored on the tank walls. These results may help to understand the response of tank wall to the dynamic pressure loading due to fluid flow in the presence of baffles. Predicted vibration response data on tank wall is provided as an excitation for acoustic analysis. Boundary Element method is used to perform acoustic analysis and predict the radiated hit noise. Tank without baffle is defined as base case and numerical simulations were performed for the same. Numerical results of the tank with and without baffle are compared with literature data. There is a reasonable agreement in terms of Dynamic Pressure and free surface elevation, and sound pressure levels. The predicted acoustic results for tank with baffle are compared to the base case to check the effect of baffles on the sloshing noise and fluid flow inside the tank.
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