چكيده به لاتين
The intake manifolds have the task of moving the air into the engine, and their dimensions and quality affect the mass flow rate and volume efficiency of the engine and thus the overall engine performance. In production lines, defects in multi-way production, caused by metal casting or plastic injection operations as well as problems with the engine connection, lead to faulty flow paths and cause changes in engine and vehicle performance. The purpose of this study is to investigate the effects of these defects on mass flow rate as one of the most important indicators of manifold performance.
In the present research, considering all the aspects of a three-dimensional simulation, seven different numerical methods have been investigated and then, by executing these simulations in the software of the fluent, on a reference model whose physics and geometry Similar to the physics and geometry of the subject matter under study and also, comparing the results obtained with the results provided by the reference example, the validation required, is carried out to identify the method that provides the most accurate and most appropriate solution. After identifying the appropriate solution method, with the simulation of the EF7 engine in the GtPower software, one hour later, and performing the validation, Input velocity data were extracted as the boundary conditions required to perform three-dimensional simulations for the three engine speeds of 2000, 3000 and 5500 rpm.
The next step is to simulate three-dimensional oscillatory flow in a simple tube as well as on the main knee geometry of the EF7 engine air intake at three different engine speeds and on four different geometries including cavities, excrescent and tolerance in The junction, we did. after examining the output pressure results and calculating the generated pressure drop and applying the calculated pressure drop effects to the one-dimensional model of the base engine through the mentioned relationships, the effects of different unevenness on the outlet mass flow rate of the air inlet manifolds We examined the EF7 engine.
Finally, it was found that the cavities, excrescent and tolerance at the junction would cause a drop of 2.73, 1.2 and 11.56% at 3000 rpm, respectively, and a 0.8, 0.5 and 5.4% drop at discharge at engine speed 5500, respectively, consider in mass flow.
