变工况下车辆燃油箱多孔挡板抑浪机理研究

车辆的变加速度工况会导致燃油剧烈晃动，发生供给中断甚至损坏燃油箱结构等现象。采用基于动网格耦合VOF的数值模拟方法和构建的水平激励试验平台，从数值与试验两个方面来分析燃油晃动过程。以某重载商用车辆燃油箱内多孔挡板为例，系统分析该挡板抑制燃油晃动的效果，探讨了多孔挡板抑浪的机理。研究结果表明：多孔挡板能够显著减小壁面压力、自由液面高度及液面轮廓起伏；燃油箱运动瞬间，挡板壁面出现瞬态局部高压，但对挡板结构的疲劳损坏程度较低；多孔挡板的孔隙将未被挡板实体部分阻碍的小部分流体分割成多股射流，急剧减缓行进波传递；多孔挡板附近流场产生涡旋，涡旋聚集和耗散能量，降低流体运动速度，达到抑制燃油剧烈晃动的目的。

Study on Wave Suppression Mechanism of Porous Baffles in Vehicle Fuel Tanks under Variable Conditions

The fuel would shake violently, and interrupt the supply, or even the fuel tank structure would be damaged in variable acceleration. The fuel sloshing process was analyzed from numerical values and experiments based on the numerical simulation of dynamic grid coupled VOF, and built a horizontal excitation test platform. Taking porous baffles in the tank of a heavy-duty commercial vehicle for example, the baffles were systematically analyzed to suppress fuel sloshing and the wave suppression mechanism was discussed by porous baffles. Studies show that the porous baffle may reduce the wall pressure, the free liquid surface height and the liquid surface profile fluctuation. The transient local high pressure appears on the baffle walls during the movement of the fuel tanks, but the fatigue damage against the baffle structure is low. The pores of the baffle divide the small part of the fluid into multiple jets, which sharply slows down the transmission of the traveling wave. The flow field near the porous baffle produces vortex which accumulate and dissipate energy, and reduce the fluids velocity. It may achieve the purpose of restraining the violent shaking.