Experiment and Numerical Analysis of Temperature Field of Cylinder Head Based on a GW4D20 Diesel Engine

Abstract

Research and/or Engineering Questions/Objective: The thermal stress field need to be evaluated for the problem of superheat of cylinder head. In this paper, the temperature field of the cylinder head of GW4D20 diesel engine was analyzed by experiment and simulation. Methodology: By the coupled finite element method (FEM), the heat transfer simulation was carried out for the combustion chamber. The method coupled together the flow of circulating coolant, the convective heat transfer of gas in-cylinder, and the heat conduction of main parts of diesel engine, such as cylinder block, cylinder head, cylinder gasket, valve seat, valve guide and so on, which were regarded as a coupled unit. The same 3D Fluid–Solid Coupled simulation analysis was also made for an improved scheme. Finally, the results of the simulation would be compared with the experimental results based on hardness plug method. Results: Temperature field of head was calculated by 3D Fluid–Solid Coupled simulation analysis exactly. The problem of superheat of GW4D20 diesel engine cylinder head was solved finally with the change of increasing baffle for each cylinder. Limitations of this study: In addition to the study on head temperature field, it also needed to consider the effect of other assembly parts and thermal mechanical fatigue of the cylinder head. The lack of experimental data limited the role of FEA in cylinder head design. What does the paper offer that is new in the field in comparison to other works of the author: The nucleate boiling was applied to research how to influence the heat transfer coefficient (HTC) of coolant side. Wall temperature of coolant jacket which was obtained by FEA in each case was made as real wall boundary of further computational fluid dynamics (CFD) calculation and more actual heat boundary of coolant side were mapped. Finally, real Fluid–Solid Coupled simulation analysis was realized and the temperature field of cylinder head was further assessed. Conclusion: The improvement scheme with increasing baffle is more feasible than the original one. And, the simulation results by the Fluid–Solid Coupled method showed a good agreement with the experimental results on an engine test bench.

F2012-A06-018