四气门柴油机进气道稳流试验研究及数值模拟

Steady Flow Test and Numerical Simulation of Air Flow in Intake Ports for 4-Valve Diesel Engine

对叫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2～10mm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，偏差都存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，同时在干涉区存袢倒流洲．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 3D numerical simulation of the steady flow in the previous three ports under the condition of steady testing by means of software FIRE of CFD, whieh calculate the flow eoeffieienl and swirl ra tio in 2-10mm 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 suits 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 baekflow phenomenon.