Simulation Research Of Intake Port Flow Characteristics In Diesel Engine

In the process of research and development of internal combustion engines, whether theintake port design rationality determines the amount of air enters into the cylinder and theability to form a swirl and tumble, which affects the combination of fuel and air, propagationspeed of flame and the extent level of combustion, ultimately, affects overall engineperformance and emissions levels.In this study, we will choose a four-valve diesel combination engine intake port as aresearch object, based on the theory of computational fluid dynamics. Apply numericalsimulation methodologies. Aim to improve the airway structure in order to increase intakeflow coefficient. Research and analyze the process of inlet gas flow characteristics of intakeport. Use port steady flow test and three-dimensional numerical simulation methodologies.First of all, there are two important parameters that evaluate the intake port performancesin the airway steady flow test, which are swirl ratio and flow coefficient values. Also requireddesired boundary conditions of obtaining numerical simulation.Secondly, measure the intake to obtain the point cloud data through reverse engineering,to establish the inlet geometry in UG software. Mesh it using AVL-FIRE software, while loadboundary conditions, turbulence model and set the desired numerical simulation algorithm.Apply CFD method to calculate the intake swirl ratio and flow coefficient at different valvelift, based on the guaranteed numerical values match steady flow test values, analyse thedetailed trends of airway velocity, turbulent kinetic energy, the three dimensional trajectorymap, flow coefficient, and swirl ratio change over valve lift, to identify the irrational designsof airway structure leads to the lower part of the airway flow coefficient, and propose theimprovement solutions.Finally, revamped the original airway model according to the improvement solutions,and simulation again. The result approves that there is an average flow coefficient increase of9.97%of the improved airway, has reached the expectation goals.