Flow Field Analysis And Structure Improvement Of Plastic Intake Manifold Based On CAD/CFD

Intake manifold is a key component of automobile engine; it's geometric shape, structure and flow characteristics affect many aspects of automotive engine, such as, performance, including intake resistance, volumetric efficiency, uniformity and gas motion in each cylinder, furtherly affec automobile engine power, economy and emission indicators. High-performance engine also needs higher designment requirment of the intake manifold. In the traditional design of the intake manifold, the performance of the intake manifold is evaluated by the steady flow test commonly. Although the steady flow test can get comprehensive volume index, but can not get detailed three-dimensional flow field information in cylinder. In the design, the designers rely mainly on their own intuition and accumulated experiences, and test method needs long cycle, high cost, and reduces the production efficiency substantially. CAD/CFD design technology in the intake manifold can be effectively used to overcome these shortcomings, therefore, CAD/CFD technology will gradually become the most popular and most effective method in the design and improvement of intake manifold.In these paper, we use CAD software to establish three-dimensional geometric model of one engine's intake manifold; use STAR-CD and ANSA software to mesh intake manifold three-dimensional geometric model respectively; and then use K-Epsilon/High Reynolds Number model to simulate the flow field in the intake manifold; use CFD software to analysis the flow field of two grid models respectively; inprove instructure of the designed intake manifold model based on analysis of flow field twice; then do further analysis of flow field for the improved intake manifold respectively, and compare the results of the flow field analysis to the results of the experiment. The results show that the performance of the intake manifold has been greatly improved and can meet the desired design objectives and requirements after twice improvements of the intake manifold; CAD/CFD technology has high accuracy, consistency with the steady flow test is also high, and provides a good theoretical basis for the designment of intake manifold.This article provides guiding research methods for the designment and the structure improvement of the intake manifold. The research method has universal generalization for the designment and the structure improvement in the manifold of the car.