DESIGN OPTIMIZATION AND ANALYTICAL INVESTIGATIONS OF HALLOW EXHAUST VALVES IN I.C ENGINES

An engine valve is a mechanical device that regulates the supply of fuel to an engine. It is an important part of any engine system and comprised of a stem and a head. Exhaust valve is precision engine components used to open to permit the burned gases to exhaust from cylinders . The heads of the valves are subjected to the high temperature of the burning gases. The Exhaust valves may reach a temperature of 800o cherry red. It is essential that they should not warp under the influence of the heat, and that their seats should not scale or corrode, as in either case they would become leaky. Therefore exhaust valve are exposed to serve thermal loads and chemical corrosion. Exhaust valve opens and closes as many as 2000 times per mile. In this thesis, various designs of hollow exhaust valves are modeled using CREO. The modeled hollow valve designs are 1) Straight hollow portion from top of the stem to the bottom of it. 2) Two hollow portions which are collinear to each other. 3) Two parallel hollow portion with a beam at the center. The hollow portion of the designs are filled with sodium. Each of the modeled design is analyzed by CFD software Fluent. It was found that the design 3 had better heat dissipation than other designs. The volume of sodium content affected the heat dissipation property and material surface affected the strength of the exhaust valve. The alternate simple fabrication method is proposed to reduce the complexity of the fabrication metho