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给出了一种能够模拟瞬态和稳态出口压力下柱塞泵流量脉动的有限元模型,并通过“二次源”法验证了该模型的有效性.首先基于斜盘式轴向柱塞泵的运行原理,应用动网格(Dynamic Mesh)技术模拟缸体、柱塞和滑靴的运动,计算运动流量;通过UDF(User Defined Function)程序定义油液可压缩性和粘性,引入柱塞泵动态流量的影响;针对流量脉动CFD(Computational Fluid Dynamics)模型巨大,串行求解器计算太慢的问题,采用并行求解技术计算流量脉动.针对现有模型难以计算出口压力突然变化和周期变化下流量脉动问题,引入动边界定义柱塞泵出口压力与时间关系,进而计算瞬态工况下柱塞泵流量脉动.对比同一模型串、并行运行时间可知,单机四核求解器可以减少73.3%的运行时间,极大地提高了运行效率;对比引入/不引入配流副、柱塞副和滑靴副油膜流量脉动仿真和实验结果,复杂模型能够提高脉动率、脉动均值和脉动幅值,因此精度更高;对比不同稳态压力下柱塞泵出口流量脉动可知,稳态压力通过影响倒灌流量影响柱塞泵出口流量脉动;出口压力周期性变化,相同脉动均值下,脉动幅值小于均值的6%时,柱塞泵出口流量脉动不随出口压力幅值的变化而变化;出口压力突变时,压力变化率越大,柱塞泵出口流量脉动变化越大;与稳态压力相比,压力变化率影响程度大于稳态压力影响程度.这些结论为“二次源法”测试条件的选择和大范围降噪方法的提出提供理论依据.
A finite element model capable of simulating the flow pulsation of the plunger pump under transient pressure and steady state exit pressure is given and the validity of this model is verified by “secondary source ” method.First, based on the swash plate axial direction The operation principle of piston pump is described. Dynamic Mesh technology is used to simulate the movement of cylinder, plunger and slipper shoe to calculate the movement flow. The compressibility and viscosity of oil are defined by UDF (User Defined Function) In order to solve the problem that the Computational Fluid Dynamics (CFD) model is too large and the calculation of the serial solver is too slow, the parallel solution technique is used to calculate the flow pulsation.According to the existing models, it is difficult to calculate the sudden change and periodicity The flow boundary of the plunger pump is defined as the moving boundary to define the relationship between the pressure and the time of the plunger pump and then calculate the flow pulsation of the plunger pump under the transient condition.Compared with the same model string and parallel running time, the single quad-core solver can be reduced by 73.3 % Of the running time, which greatly improved the operating efficiency; compared with the introduction / non-introduction of flow pairs, the deputy deputy of the piston and slipper oil film flow pulse simulation and experimental results, the complex model can be improved High pulsation rate, pulsation mean value and pulsation amplitude, so the accuracy is higher. Comparing the pulsation of outlet flow of plunger pump under different steady-state pressures, it can be known that the steady state pressure affects the pulsation of outlet flow of plunger pump by influencing the backfill flow rate; . When the pulse amplitude is less than 6% of the mean value, the pulsation of the outlet flow of the plunger pump does not change with the amplitude of the outlet pressure at the same pulsation mean value. When the outlet pressure suddenly changes, the pressure change rate becomes larger and the pulsation of the outlet flow of the plunger pump fluctuates The bigger the pressure change rate than the steady state pressure.The influence of steady state pressure is larger than that of steady state pressure.These conclusions provide the theoretical basis for the selection of “secondary source method” test conditions and the method of wide range noise reduction.