Integrated Simulation Methodology to Predict Engine Head, Block, and Piston temperatures.

With the constant strive towards increase in performance and corresponding stringent emission standards of modern IC engine, engine components such as the head, block and piston are subjected to higher thermal loads. This is why it is important to mitigate failures early in the design cycle of any engine program. An integrated simulation methodology is proposed where the head, the block and the piston are integral part of the analysis. The CFD – CHT methodology is used to simulate and predict the temperature of these engine components. The head and block are run in a steady-state conjugate heat transfer framework while the transient multiphase volume of fluid (VOF) approach is used to predict piston temperatures. Combustion surfaces boundary conditions are derived from 3D CFD open-loop combustion simulation, while cooling and lubrication surface boundary condition are mapped from 1D system simulation or experimental data. The heat transfer boundary conditions are swapped between the two simulations. The temperature field obtained from simulation is used further as input to perform the thermo-mechanical fatigue analysis to predict the useful life and durability of engine and piston. Physics involving nucleate boiling and contact resistance are also incorporated and studies are conducted to predict their sensitivity. The simulation methodology is applicable and validated for diesel, natural gas, spark ignition and hydrogen engines. A good correlation is established between the simulation and experimental validation. This study serves to predict the location of critical failures, optimize the design faster and save time and costs for the organization. Keywords: IC Engine – Internal combustion engine, CFD – Computational Fluid Dynamics, CHT – Conjugate heat transfer analysis, VOF – Volume of fluid, 1D – one dimensional, Thermo-mechanical fatigue, Nucleate boiling, Contact Resistance