CFD modeling of surge tank degassing process

提高发动机功率输出和效率，同时满足环境要求，一直是全球汽车制造商的主要目标。发动机冷却系统对这些目标有很大的影响。冷却系统不仅可以防止发动机内部零件由于燃烧燃料的热量而熔化，而且还可以使发动机的工作温度保持在最有效的水平。作为冷却系统的一个组成部分，缓冲罐作为除气室，可以持续有效地去除任何蒸汽（空气和/或蒸发的冷却剂）。否则，如果蒸汽被捕获并在系统中循环，则可能严重降低发动机水套和散热器中的传热效率，并且由于气泡的内爆而腐蚀水泵。缓冲罐为整个冷却系统提供了巨大的好处。然而，对于那些具有相对高的流体流速的缓冲罐，由于空气/蒸汽破裂成小气泡，使冷却剂脱气变得更加困难。ABC集团- 一家总部位于美国的汽车行业轮胎供应商-为全球汽车原始设备制造商设计和生产压力缓冲罐/冷却液回收，作为其重要的塑料产品之一。ABC集团已经确定，非常需要通过深入了解脱气现象（涉及液体冷却剂、蒸汽冷却剂和空气的混合物）来改进缓冲罐设计。

Increasing engine power output and efficiency, whilst still satisfying environmental requirements, have been major objectives for vehicle manufacturers worldwide. An engine cooling system has a great influence on those objectives. The cooling system can not only prevent the internal engine parts from melting due to the heat of the burning fuel, but keep the engine operating temperature at its most efficient level as well. As an integral part of the cooling system, a surge tank serves as a degassing chamber, allowing for continual and effective removal of any vapor (air and/or vaporized coolant). Otherwise, the vapor, if trapped and circulated in the system, may seriously degrade heat transfer effectiveness in the engine water jacket and radiator and erode the water pump due to the implosion of gaseous bubbles. A surge tank provides a huge benefit to the overall cooling system. However, for those surge tanks with relatively high fluid flow rates, it becomes more difficult to de-aerate the coolant due to the fracture of air/vapor into small bubbles. ABC Group Inc. - a Canadian-based tire 1 supplier in automobile industry - designs and produces pressured surge tank/coolant recovery, as one of its important plastic products, for automotive OEMs worldwide. It has been identified by the ABC Group that there is a strong need to improve surge tank designs by having in-depth understanding of the degassing phenomena, involving mixture of liquid coolant, vapor coolant and air.