对四气门柴油机的单螺旋、单切向、组合气道进行了气道稳流试验，测量出流量系数和涡流比。保持与气道稳流试验相同的边界条件以及气道评价方法，通过CFD软件FIRE对上述3种气道进行三维稳态数值模拟，计算2～10 mm各气门升程下的流量系数和涡流比。将稳流模拟所得结果与气道稳流试验所得结果比较，两者吻合良好，偏差都在5％范围内，验证了数值模拟计算的可行性。对缸内气流的速度场、湍动能等值线场进行了分析，得出3种气道的涡流流动特征，组合气道的两气流发生干涉，导致该处有一定的流量损失，同时在干涉区存在倒流现象。%This paper have done steady flow test of single helical , tangent and double ports in a 4-valve diesel engine for measuring the flow coefficient and swirl ratio .The 3 D numerical simulation of the steady flow in the previous three ports under the condition of steady testing by means of software FIRE of CFD , which calculate the flow coefficient and swirl ra-tio in 2-10 mm valve lift .It shows that the results of steady-state simulation are in good agreement with its test results , and the deviations are within 5%, when the results of simulation compared with test results , which verify the feasibility of the numerical simulation .After analysing in-cylinder flow velocity field and turbulent kinetic energy contour field , the re-sults point that come the swirl flow characteristics of the three ports In double ports , there is a certain loss of flow in the interference of the double gas flow , where exists backflow phenomenon .
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