The Application Research Of Non-parameter Optimization Technology In Design Of Cylinder Head

With the rising of engine power density,the components of engine,especially cylinder head,are subjected to increasingly severe thermal and mechanical loads.To pursue the lightweight and durability design of diesel cylinder head,the non-parametric optimization method that combined the finite element analysis technology with the structural optimization technology was used to carry the topology optimization and shape optimization research on a diesel cylinder head,and the design was achieved.Compared with the original cylinder head,the new cylinder head had 10.9%decline of the mass and20℃decline of the highest temperature.And the Mises stress value in the exhaust valve bridge,intake-exhaust valve bridge,intake valve bridge,the injector seat hole area,the fillet between valve guide wall and the roof and the fillet near bolt hole decreased respectively by 19%,4.9%,4.9%,5.1%,7.96%and 5.6%.And the maximum plastic strain in fire-deck area decreased by 29%.Results indicated that applying the cylinder head non-parametric optimization design flow to achieve the lightweight and durability design of cylinder head was feasible.The main contents are as follows:（1）Conducting the topology optimization research on a cylinder head.At first,cylinder head concept model was established and divided into four design area:fire-deck,side wall,rear wall and roof.Followed by topology iterative design under maximum rigidity objective,topology optimization results were obtained.Then disposal principles aiming to topology optimization results were proposed.According to these results and principles,the engineering solutions of fire board,side wall,rear wall and roof were determined.Finally the new cylinder head design was achieved.（2）To evaluate the optimization effect,the simulation analysis of static strength was conducted on original cylinder head and new cylinder head.（3）Conducting the shape optimization research on water jacket surface.Transitional fillet areas were determined as design domain and conducted optimization iteration under the objective ofmin（max（σ₁））and min(max(σ_mises))..