The Application Of CFD To Evalution And Improvement In Diesel Intake Port

The structure of intake port directly affects the quantity of fresh air and the strength of swirl in cylinder, which have relations with mixture forming, so affects the combustion, exhaust and total performance. Based on experiential design and steady flow test, the traditional port design method needs a long developing period, moreover is hard to get the ideal scheme. Using 3D numerical simulation, the reserch on intake port could acquire not only the integration parameters, but also microcosmic information of the flow field in abundance, which provides important basis to improve and design the intake port optimizingly.In this dissertation, the author summarizes the development and research on diesel intake port; selects the mathematici and numerical models of flow in port; simulates the helical intake port of YCF3200 three-dimensionally in CFD software AVL FIRE, by upbuilding the geometric model via reverse engineering and using the results of steady flow test rig as boundary conditions; gives the rule how to judge the endof calculation in CFD simulation of port for the first time; validates the calculational results via the Ricado and FEV evaluation acquired through test rig, and draws a conclusion that the two have a basicly accordant trend, which shows the feasibility of applying CFD to evaluation in diesel intake port; provides detailed flow field information of the port, on the basis of which table a proposal of port improvement; after the modification on the cylinder head following the proposal, tests it on the steady flow test rig and the results accord with forecast, which farther shows the validity of applying CFD to improving diesel intake port. The author for the first time applies the flow field results to guide the port modification and achieves the purpose of taking effect quickly and lowering cost during development.