Design and manufacturing process simulation of sheet metal exhaust manifold for turbocharged bi fuel engine

High thermal strength, low weight and capability of fast catalyst convertor warm up are main advantages of sheet metal exhaust manifolds which made it the best option for engines with maximum exhaust temperature more than 900 ͦC. A sheet metal exhaust manifold has been designed in this paper for EF7-TC engine which is four stroke bi-fuel CNG-gasoline engine. The proposed sheet metal exhaust manifold would be replaced with current Ni resist cast iron manifold. Design of exhaust manifold has been undertaken following the packaging constraints in the engine and required exhaust gas flow characteristics. Manufacturing process of design sheet metal exhaust manifold was simulated using AUTOFORM software. In finite element analysis effects of sheet thickness, its material and friction coefficient were investigated on sheet tearing. Results showed that AlSI321 can be used as a material for sheet metal with designed geometry. And drawing of sheet with these characteristics can lead to no defects on final formed sheet.