Numerical Simulation Study On Intake Flow In JE482 Gasoline Engine

It is sufficient fresh air that determines the quality of the mixture and the combustion process in a SI engine. Therefore, the effective way to improve the engine power is to enhance the flow coefficient and to reduce the inlet flow resistance. As the intake flow characteristics are sensitively influenced by the changing in shape and size of the key position of a intake port, it is important to optimize intake port structures for the improvement of engine performance.Traditionally , steady-state flow rigs are extensively used in the amelioration of intake ports for engines, which was performed to evaluate the amelioration effect of intake port. But experimental method can only offer global parameters; it is not easy to get the detailed information about the intake flow structure. The amelioration design heavily relies on the designer's experience and intuition. Therefore, the amelioration cycle has been enlarged, and it's very difficult to make a ideal design plan. CFD technology can be used to solve this problem by simulating the intake flow in the intake port which is modeled in CAD software. It can provide three-dimensional flow structure details in the intake port model. It turns out to be quicker to find out the bad flow areas more accurately. So it takes less time and money to obtain a good amelioration plan. It's evidenced that the combine of using steady-state flow test and CFD simulation is a effective way to amend intake ports.In this paper, the steady-state flow rigs tests for an original and a referenced intake port (intake ports for a 1.6L and a 2.0L gasoline engine) has been carried out to get the flow coefficients of each port at different valve lifts. The tests were both under a steady pressure drop. And flow coefficients of these two ports are measured to evaluate the flow capacity. The flow coefficient of the 2.0L gasoline engine is higher than that of the 1.6L engine by 9.7% in average. Some differences were found through the contrasting of the structure of these two intake ports: the diameter of the main flow area in 2.0L engine's intake port is 2.5mm bigger than that of the 1.6L engine's intake port. And refer to the intake port head, both the height and the width of the 2.0L intake port are bigger than those of the 1.6L intake port by 1.5mm and 2mm. It is primarily supposed that the difference of the structure derives that of the flow coefficient.Numerical simulation was carried out on steady-state flow test of both 1.6L and 2.0L engine. The flow coefficient and three dimensional flow features such as pressure fields, velocity fields and turbulent kinetic energy values were obtained as simulation results. It was qualified that the...