Main Article Content
Nowadays, motorbikes are still the main and most popular transport in Asian countries, especially, in Vietnam. However, the manifold intake systems in motorbikes are usually designed in a simple structure, which can reduce engine performance and increases fuel consumption in motorbikes. This paper presents the study of the improvement of the intake system in a 125cc motorbike engine to enhance air-fuel mixing quality that can increase the engine performance. The study employs the ANSYS software to obtain an optimal intake system
through the tumble and swirl ratios in different simulation cases. Another model was
also built by Matlab/Simulink to examine the effects of swirl and tumble ratios on engine performance and fuel consumption at various engine speeds. The simulation results show that the modified intake system with
an incline angle of 30o has optimal tumble and swirl ratios. Accordingly in conclusion, power output and torque of the engine with the modified intake system are higher, while the fuel consumption is lower than previously
 Lee S, Tong K, Quay B, Zello J, Santavicca D. Effects of Swirl and Tumble on Mixture Preparation During Cold Start of a Gasoline Direct-Injection Engine. CEC/SAE Spring Fuels & Lubricants Meeting & Exposition. 2000.
 Agrawal A, M P. In Cylinder Cold Flow CFD Simulation of IC Engine Using Hybrid Approach. Conference on Advances in Mechanical Engineering (NCAME 13). 2013.
 Shafie AM, Tahir M, Ali M, Bakar R, Ym A. Intake analysis on four-stroke engine using CFD. ARPN Journal of Engineering and Applied Sciences. 2015;10:7799-804.
 Weeks RW, Moskwa JJ. Automotive Engine Modeling for Real-Time Control Using MATLAB/SIMULINK. SAE Transactions. 1995;104:295-309.
 Gundmalm S. CFD modeling of a four stroke S.I. engine for motorcycle application [Master Thesis]. 2009.
 Heywood. Internal Combustion Engine Fundamental. 1th ed. United States: McGraw-Hill Education; 1998.
 ANSYS. Internal Combustion Engines in Workbench. U.S.A; 2013.
 Shamoon Jamshed. Introduction to CFD. Elsevier; 2015. DOI: 10.1016/B978-0-12-801567-4.00001-5.
 Addepalli SK, Mallikarjuna JM. Parametric analysis of a 4-stroke GDI engine using CFD. Alexandria Engineering Journal.
 Hamid MF, Idroas MY, Sa’ad S, Yew Heng T, Che Mat S, Zainal Alauddin ZA, et al. Numerical Investigation of Fluid Flow and In-Cylinder Air Flow Characteristics for Higher Viscosity Fuel Applications. Processes. 2020;8(4):439.