1Amrita School of Engineering.
2Dr. N.G.P Institute of Technology.
The valve, or valve port together, is usually the most important flow restriction in the intake and the exhaust system of four-stroke cycle engines. The volumetric efficiency in an IC engine, and therefore the power output, could be increased with improvements to the design of the inlet valve. In the inflow of air dynamics, the port and valve restrictions play a vital role in maximizing the mass flow rate. This paper identifies the sensitivity of the inlet valve geometry for a range of L/D ratios using CFD code Fluent 6.2.18 with the RNG k-ɛ turbulence model. The detailed flow characteristics, indicating flow separation and reattachment were established. The effects of minimum, intermediate and maximum valve lift regime and back flow at instantaneous piston speeds were evaluated and predictions assessed. The results indicate the sensitivity of the valve parameters to small changes in the parameters like seat angle, cone angle and fillet radius to valve diameter ratio. With geometrical modifications the transition points can be altered leading to improvement in valve flow characteristics and therefore the performance of the inlet port.
