基于Fe3O4-乙二醇纳米流体的直喷汽油机冷却水套传热研究

摘要

The glycol coolant added with Fe3O4 nano particles was used as the coolant of gasoline direct injection engine.Then the heat transfer of water jacket flowed through by different prepared coolants was analyzed with CFD Fluent software and the computation accuracy improved by considering the change of physical parameters such as thermal conductivity and specific heat capacity with temperature.The flow field, the pressure field and the wall temperature distribution were obtained by the simulation.The results indicate that nano-fluid can improve the engine heat transfer capability.The wall temperature of water jacket drops evidently and the higher mixing concentration leads to better cooling effect.%在乙二醇冷却液中添加Fe3O4纳米粒子作为直喷汽油机冷却液,利用CFD软件Fluent对不同浓度冷却液下直喷汽油机冷却水套的传热进行了三维模拟计算,并考虑纳米流体导热系数、比热容等物性参数随温度的变化来提高计算的准确性,计算得到冷却液的流场、压力场及壁面温度的空间分布.结果表明,与传统冷却液相比,以Fe3O4-乙二醇纳米流体作为冷却液能够提高内燃机的散热性能,水套壁面温度降低明显,且浓度越大冷却效果越好.