The Numerical Simulation Study Of Gasoline Variable-length Intake Manifold

Within a wide speed range, engine design workers hope as much as possible to get theintake air into cylinder. Variable intake manifolds which is one of the best technology can makeit ture.And it also ensures the engine has more fresh charge under the high-speed and resolve theproblem of lower swirl and tumble flow motion under the low-speed.By using one-dimensionaland three-dimensional numberical simulation method, paper main researches the influence ofvariable intake manifolds on the performance for gasoline engine.The study in this paper is on the basis of the variable intake manifolds development projectfor the K14B-H engine.A certain gasoline engine model was set up by using1D simulationsoftware GT-POWER,and the main parameters are on the original engine. By changing thelength of the intake manifold, the cross section diameter and stabilized cavity volume, we canobserve the proformance of engine torque, power and fuel consumption. The optimal structureparameters were elected, and a set of scheme for length determination of variable intakemanifolds was summarized.Using three-dimensional drawing software design a three dimensional model of the variableintake manifold,and the structure parameters based on one dimensional simulation.Thethree-dimensional numerical simulation of airflows in mainfold was performed using CFDsoftware STAR-CCM+. First for steady-state simulation,we can observe the liquidity situationand uniformity of the long and the short pipe. In the transient simulation,we can get theinformance about airflows in each mainfold when the intake valve opening and the maximum liftposition by using1D-3D coupling method in different situations.This article uses computer.aided systems, using modern integrated study methods.Throughthe parallel analysis of the engine cycle simulation of one-dimensional and three-dimensionaland the design and test of parallel tools,it found that using the method can accelerate product development cycles,cost savings and high quality completed development tasks. In the last,theresult of simulation shows that the torque increased by3.67%and power increased by4.63%than the original gasoline.