Improving the biogas engine performance by implementing the pressurised turbulent flow is discussed in this paper. The pressurised flow will increase volume of the fuel; hence improve the volumetric efficiency and the turbulence will increase the homogeneity of mixture; hence improve the flame speed. It is also known that the inlet port design and the intake manifold configuration have a direct influence on engine performance and emissions. Based on this fact, the intake process may give a great contribution towards increasing the Biogas engine performance; the paper focuses on the design and analysis of the fuel intake system as economical devices without major modification. It includes analytical design of an intake system for biogas operated single cylinder 4-S spark ignition engine.

For the use of Biogas as a fuel in the SI engine some modifications are done. The improvement of flow strategy is implemented in the intake system of the engine to produce better biogas engine performance. The intake system for airfuel mixture is studied, designed, simulated and analyzed with ANSYS-CFX and CFD-Post code. A venturi with an inlet for air at nozzle convergent section and for biogas at throat with providing an accelerating device for maintaining flow of biogas is done. In CFD analysis the effect of flow of air-fuel mixture with the contoures of pressure, velocity, kinetic energy and streamlines are studied. Form that results the effect of break power, air/fuel ratio, bsfc at the speed 1000rpm, 3000rpm, 5000rpm and 7000rpm are studied. In this study it is found that the break power at the respected speed are 0.96kW, 1.7kW, and 2.7 kW, 5.3kW resp. Whereas the specified speed of standard petrol engine comes near about same as that of biogas speed at 7000rpm.