Search Results

A flow model is developed by a finite difference method to analyze the flow in the chamber type intake manifold. The model is based on one dimensional compressible unsteady flow. To obtain stable and accurate solutions, the appropriate boundary conditions for the intake chamber, intake ports and cylinder are formulated. In order to verify the simulation results for the flow model, the calculated results are compared with the experimental measurements. By analyzing pressure waves in the intake system, the optimum intake chamber volume, intake pipe length, at various engine speeds are presented. Finally, the optimum valve timings at different engine operating conditions are sought by this model.

A flow model is a convenient tool for developing the engine intake system. Two flow models for the branched engine intake were developed by the finite difference method and the method of characteristics. The results from the models were compared with the experimental data and the appropriate boundary conditions were established for each model. Modeling the flow at the intake and exhaust valves with a cylinder and at the pipe branches were the most critical part of the flow models affecting the accuracy of the solutions. From two models, it was found that the finite difference model was simpler than the characteristic model in formulation with the better accuracy. The effects of valve timings and intake geometry were studied by the flow models to design the optimum intake system.