进气歧管的进气均匀性是发动机的重要性能指标，仿真计算是指导进气歧管设计优化的重要手段，仿真过程是否合理对计算结果的影响较大。针对两款采用行业内最常用计算数据模型和计算工况将均匀性已优化合格的进气歧管，利用star-ccm+软件分别比较其仿真模型在考虑不同的质量流量、节气门角度、入口管路等因素后的进气均匀性差异，探究更精细化计算模型。结合稳流试验台测得的流量系数偏差用以证明计算结果及计算设置模型的可靠性，并结合计算流场和流体理论的分析，最终得出：选取单一质量流量或压差作为计算输入较合理；节气门阀板角、节气门前进气弯管等更贴近实际的入口结构因素对进气均匀性的计算结果存在较大影响，以上因素使得用初始模型已优化至1%以内的歧管不均匀度呈现3~10倍不等的恶化；另外，节气门前后的直线段长度对均匀性也有影响。

The intake uniformity of manifold is an important performance index of engine and the simulation and calculation is an important method for its optimization. Whether the simulation process is reasonable or not has a great influence on the calculation results. Two intake manifolds were respectively optimized and accepted with star-ccm+ software based on the intake uniformity by using the industrial most commonly used calculation model and condition. Then the comparison of intake uniformity difference was conducted after introducing factors such as different mass flow rates, different throttle angles and inlet pipes and the more accurate model was further analyzed. The calculation results and established model were reliable according to the measured flow coefficient deviation on the steady flow test bench. It was concluded that the single mass flow or pressure difference is reasonable to be taken as input of simulation through further combining with computational fluid field and fluid theory. The factors of inlet structure had a great influence on the uniformity calculation, which were close to the actual and included throttle angle and inlet elbow before the throttle. Considering these factors, the unevenness within 1% optimized with the initial model would worsen by 3-10 times. In addition, the length of straight line before or after the throttle also had influence on the uniformity.