机车柴油机进气道的仿真计算及结构优化

为了改进16V240ZJB型柴油机性能，借助模拟计算与气道稳流试验相结合的方法，首先利用三维造型软件UG对气道进行实体建模，然后利用气道稳流试验数据为模拟计算提供边界条件，以AVL—FIRE软件为平台，采用合适的湍流模型和计算方法对气道内的三维流场进行数值模拟，得到了不同气门升程下详细的流场信息。气道性能评价参数（流量系数和涡流比）的计算结果与稳流试验台的试验结果吻合较好，验证了应用数值模拟方法评价气道的可行性；通过流场分析，找到了气道不合理的部位，提出了气道改进措施，并再次进行了数值模拟计算。计算结果表明，改进后的气道结构在大升程下进气流量得到明显提高，进气流动状态也得到了很好的改善。

Simulation and Structural Optimization of the Intake Port in Locomotive Diesel Engine

By integrating numerical simulation and steady flow testing of the intake port, e. g. , a solid modeling of the intake port with 3 - D modeling software （UG） and the boundary conditions for simulation generated by steady flow test data, the flow fields under different valve lifts are obtained with the help of AVL - FIRE software which implements numerical simulation of 3 -D flow fields in the intake port by utilizing proper turbulence models and computing methods. The calculation of the performance evaluation parameters （flow coefficient and turbulence ratio） of the intake port coincides well with the test results of steady flow, which verifies the feasibility of assessing intake port with numerical simulation. With the aid of flow field analysis, improper positions in the intake port are pinpointed and improvement approaches to the port are proposed, following a numerical simulation once again. Calculation indicates that the inlet flow of the modified intake port structure is greatly increased and the inlet flow condition is consequently improved, which will surely contribute to the performance enhancement of 16V240ZJB diesel engine.