Cavitation of engine cooling water pump is a main factor for noise and vibration, and decreasing service time of automotive cooling system. To improve the anti-cavitation performance of engine cooling water pump, the three-dimensional turbulent flow in cooling pump was simulated employing the time averaged N-S equation, the standard k-e two equation turbulent model and multiphase flow model of CFX software. Cavitation flow distribution in the impeller of cooling water pump was observed. Compared with experimental data, the experimental head of the pump is 6.1 m at the design flow rate of 285 L/min, which is lower than that of numerical simulation under room temperature. Serious cavitation occurs under actual operating conditions. Experimental NPSH of the pump is 9.8 m at 85 ℃, which is consistent with the simulation results. Two methods that slow cavitation of engine cooling water pump were proposed. They can improve the cavitation performance. Anti-cavitation performance is improved with reducing blade number.%发动机冷却水泵的空化破坏是缩短汽车冷却系统寿命、产生振动噪声等危害的关键因素.为了提高发动机冷却水泵的抗汽蚀性能,以时均N-S方程作为基本控制方程,采用标准k-ε双方程湍流模型及多相流模型,利用CFX流体计算软件模拟了发动机冷却水泵内部的三维湍流,并观察叶轮内部空化流场的分布.通过试验对比验证,水泵在285 L/min设计流量下扬程为6.1m,远远低于常温下的数值模拟扬程,说明该泵在实际运行工况下已发生严重空化；在85℃下,模型泵试验汽蚀余量为9.8 m,与数值计算结果基本一致,说明数值计算结果是可靠的.并由此提出了两种减缓发动机冷却水泵发生空化的有效方法,两种方案均能较好改善泵的空化性能,且减少叶片数方案抗汽蚀性能更优.
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