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为了揭示核主泵叶轮和导叶的流动干涉效应,采用相似换算法和多参数匹配法,基于RNG k-ε湍流模型与块结构化网格,对缩比系数为0.5的模型泵进行非定常数值模拟。结果表明:扬程脉动幅值与运行工况有关,额定工况时扬程脉动的幅值最小,偏离最优工况时,扬程脉动幅值逐渐增大。导叶内部流道产生不稳定的流量脉动效应,大于0.8Qd工况时,导叶内流量脉动瞬态效应不明显;小于0.8Qd工况时,导叶内流量脉动趋于不稳定。考虑到机组的水力稳定性,运行工况应大于0.8Qd。动静干涉使导叶内静压分布呈现周期性脉动,导叶压力面平均脉动幅值最大,吸力面平均脉动幅值最小,压力脉动的周期与叶轮叶片数有关;导叶内静压分布与叶轮尾缘和导叶前缘相对位置有关,叶轮尾缘对导叶入口流动的阻塞效应,是诱发导叶内静压脉动的主要原因。
In order to reveal the flow interference between the main pump impeller and the guide vane, the model pump with scaled coefficient of 0.5 was unsteady based on the RNG k-ε turbulence model and the block structured grid using the similarity conversion method and the multi-parameter matching method. Numerical Simulation. The results show that: the amplitude of lift pulsation is related to operating conditions, and the amplitude of lift pulsation is the minimum when operating condition is rated. When deviation from the optimal operating condition, lift pulsation amplitude gradually increases. Vortex flow in the guide vane instable flow, when 0.8Qd working conditions, the flow vane transient effect is not obvious; less than 0.8Qd working conditions, the flow guide vane flow instability. Taking into account the hydraulic stability of the unit, operating conditions should be greater than 0.8Qd. The static and dynamic interference makes the static pressure distribution in guide vanes periodic, the average pressure amplitude of guide vanes is the largest, and the average pulse amplitude of suction surface is the smallest. The period of pressure pulsations is related to the number of impeller blades. The relationship between the trailing edge and the relative position of the leading edge of the guide vane. The obstruction effect of the trailing edge of the impeller on the flow at the guide vane inlet is the main reason for inducing the hydrostatic pulsation in the guide vane.