Evaluation of flow paths due to leakages of flammable liquids by the SPH method. Application to real engines. 2020-01-1111
One the most important safety issues for automotive engineering is to avoid any fire due to the ignition of flammable liquids, which may result from leaks. Fire risk is a combination of hot temperature, fast vaporization and accumulation of vapor in a cavity. In IC engines, potentially flammable liquids are fuel and oil. To guarantee safety, no flammable liquids must come into contact hot parts of the engine. Consequently, shields are designed to guide the flow path of possible leakages and to take any flammable liquid out of the hot areas.
Simulation is a great help to optimize the shape of the shield by investigating a large number of possible leakages rapidly.
Recent breakthroughs in numerical methods make it possible to apply simulations to industrial design concepts. The approach is based on the Lagrangian Smoothed Particle Hydrodynamics (SPH) method. The SPH method is an efficient method to capture the rivulets on highly complex geometries and thus determine the relevance of the design.
A new implicit algorithm was developed to make the simulations faster. Preliminary tests on representative mock-ups of existing shields have been performed to characterize the accuracy of the simulation and to help to determine the best numerical set-up. Visualizations by CCD camera of different leakages by variation of fluid, mass flow, localisation (…) have been applied to generate a large experimental data base. Simulation results have been compared.
Finally, simulations on a real engine have been completed and results have been analysed with the help of immersive visualization.
Frederic Ravet, Nathan Dabert, Simon Ameye, David Greif, Jens Cornelis, Markus Ihmsen
Renault, DPS, AVL France, AVL LIST GmbH, FIFTY2 Technology GmbH