Development of a technique for calculating the heat-stress of the CHN21/21 diesel engine cylinder head

The acceleration of the engine and the intensification of the working process lead to the maximum gas pressure increase in the cylinder as well as to an increase in the thermal stress of its components. Hence, it is necessary to perform modelling of the heat-stressed-deformed state (HSDS) of the main elements forming the gas joint of the engine. The object of the study is the diesel CHN21/21 cylinder head. In order to increase the reliability and performance of this family of engines, it is necessary to study the heat exchange between the working fluid and the main engine components as well as the calculation of the HSDS of the main engine parts, in particular, the cover of the cylinder. The developed methodology for calculating the HSDS of the cylinder cover allows one to take into account local thermal boundary conditions that increase the accuracy of the calculation. To evaluate the HSDS, a three-dimensional finite element model of the sleeve assembly, the cylinder cover and the block interacting within the gasket location zone has been used. For calculating and direct modeling with the help of finite element methods (FEM) the ANSYS software complex was used. The design grid was generated automatically, and in the stress concentration zones a number of similar calculations were performed with different degrees of the “thickening” of the grid. The parameters of convective heat transfer set on the shell surfaces resulted from ICE program calculation the workflow parameters of which had been obtained earlier from the AVL Fire software package. HSDS calculation of the cylinder cover was carried out taking into account the SDS of the assembly unit mounting loads and considering the tightening force of the power pins and the fuel injector. As a result, equivalent stresses were obtained for all parts of the calculation model.

AVL Fire, ANSYS, piston engine, diesel, heat flow, workflow, AVL Fire, ANSYS, finite element method, boundary conditions, temperature field, installation loads

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