含隔板球形贮箱液体晃动激励频率影响分析

Effect of excitation frequency on the liquid sloshing in spherical tanks with baffle

针对航天器球形贮箱液体大幅晃动问题,采用光滑粒子流体动力学方法(SPH)对液体进行建模:基于SPH方法基本方程推导出N-S方程的数值解,并给出人工黏度项、压力项表达式,选择动态边界法处理边界计算问题。建立光滑内壁球形贮箱及带防晃隔板球形贮箱两种模型,设计力模式、运动模式两种激励形式并选择三种激励频率进行仿真分析,分别记录舱壁受力及测点压强。仿真结果表明:激励频率取为1.5 Hz时,舱壁受力最大;隔板能够减弱液体晃动对舱壁产生的作用;液体晃动现象的产生使得舱壁在y,z两方向的受力均增大;位于液面以下的舱壁所受压力具有“双波峰”特性,而隔板的存在对压力峰值具有“平均化”效果,避免局部压力过大;位于液面以上的舱壁所受压力表现为“脉冲波”形式,随激励频率的增加隔板对舱壁压力的削弱效果越明显。

The smoothed particle hydrodynamics(SPH)was utilized to solve the liquid sloshing in spherical tanks of spacecraft.The numerical solutions of Navier-Stokes equations were deduced,along with the artificial viscosity and pressure term appropriately expressed and the boundaries properly dealt with by using the dynamic boundary treatment.Two kinds of spherical tanks were built,one with baffle and the other without.Two types of harmonic excitations were designed,the force type and the motion type,with three different frequencies.The force applied on the bulkhead and the pressure at measuring points were measured.The simulation results show that:when the excitation frequency is 1.5 Hz,the force applied on bulkhead reaches its maximum.The pressure curve at the measuring point beneath liquid level has“double-peak”,the baffle can balance the two peaks and decrease the maximum pressure.The pressure curve at the measuring point over liquid level is of the form of“impulse wave”,the depression effect of baffle enhances with the increase of frequency.