The fluid motion in partially filled tanks with internal baffles has wide engineering applications.The installation of baffles is expected to reduce the effect of sloshing as well as the consequent environmental damages.In the present study,a series of experimental tests are performed to investigate the sloshing phenomenon in a baffled rectangular storage tank.In addition,the sloshing phenomenon is also modeled by using OpenFoam.Based on the experimental and numerical studies,optimization of the geometric parameters of the tank is performed based on some criteria such as tank area,entropy generation,and the horizontal force exerted on the tank area due to the sloshing phenomenon.The optimization is also carried out based on the entropy generation minimization analysis.It is noted that the optimum baffle height is in the range of hb/hw=0.5-0.75 in the present study(where hb and hw are the baffle height and water depth,respectively).Based on the results,the optimal design of the tank is achieved with RA= 0.9-1.0(where RA=L/W,L and W are the length and width of the tank,respectively).The results also show that the increase of hb can lead to a decrease of the maximum pressure and horizontal force exerted on the tank.It is also noted that the horizontal force exerted on the tank firstly continues to increase as the sway motion amplitude increases.However,as the normalized motion amplitude parameter,a/L(The parameter a is the motion amplitude),exceeds 0.067,the effect of motion amplitude on the force is not obvious.The same optimization is also performed in the multiple-variable-baffled tank and prismatic storage tank.