Abstract :
In recent years, with the development of the economy, the automobile industry has also undergone ever-changing changes. At present, the design of the engine in addition to the car to achieve the dynamic, economic indicators but also need to meet their emissions and noise requirements, it is necessary for the engine into the exhaust system for in-depth study. The intake system mainly comprises two parts of the pipeline and the intake manifold before the intake manifold, in which the pipeline in front of the manifold acts to reduce the intake noise. How to design the components of the intake system reasonably and analyze its comprehensive performance is the most important topic in the project.
Firstly, this article introduces the principle of variable valve timing and variable intake manifold technology,
establishes B15 engine model in GT-Power software and uses the test data to complete the calibration of the model so that the error is not more than 5% for subsequent simulation calculations. In order to design the silencer element of the intake system, the sensitivity of the parameters of the Helmholtz resonator, 1/4 wavelength tube and air filter is calculated and analyzed, and the influence of the parameter change on the muffler performance is summarized. The design flow and method of the intake muffler element are described in detail, and the concrete design scheme is put forward. The noise of the muffler element is optimized according to the problem that the noise of the individual order is higher than the target value. After the optimization of the intake system air intake noise improved significantly, the pressure loss is no higher than 2.5 kPa, in line with the target value requirements, the optimization effect is good.
Secondly, in order to analyze the performance of the intake manifold, three methods are proposed: the zerodimensional or one-dimensional model is used to simplify the processing, and the CFD software is used to calculate the steady-state or isolated transients and the coupling analysis using one-dimensional and three-dimensional software. By comparing the advantages and disadvantages of the three methods, it is found that the coupling of software can obtain realtime boundary condition in the calculation process and have high accuracy. This paper focuses on the key issues that need to be solved by coupling with GT-Power and STAR-CCM + software and completes the calculation of the model.
Finally, in order to evaluate the advantages and disadvantages of the intake muffler element better, the maximum noise of the intake system is calculated by using the model of the vehicle acceleration in the GT-Power software, and the maximum noise of the intake system is 61.8 dB (A) which satisfies the target requirement for the individual contribution rate through noise.
Keyword :
B15 engine design, Exhaust and intake system, GT-Power, noise and emission control