Simulation methodology for hydrogen concentration and dilution strategy in a hydrogen fueled internal combustion engine

Manufacturers of internal combustion engines are changing their focus to non-conventional fuels like hydrogen in response to the worrying global warming situation. When compared to conventional fuels like gasoline or diesel, the use of gaseous hydrogen fuel in an internal combustion engine powered by hydrogen can lessen the engine's negative environmental effects. But occasionally, hydrogen can leak to the engine top cover through the high-pressure fuel injection system or as blowby within the crankcase. Static zones may emerge as a result of these H2 leaks. Potential explosion or fire can result when the H2 concentration in these stagnation zones is more than 4% and triggers a minimum ignition energy of 0.02 mJ. A CFD simulation methodology incorporating multi-species model, piston, and crank motion is developed to estimate the H2 concentration within crankcase. The blowby values are determined from the experimental measurement and used as the inputs. The dilution strategy and system design for crankcase is examined using this simulation an. Further, for under hood and engine top cover, under the hood is carried out to ascertain the accumulation within the engine and its compartment. Hydrogen ICE engine blowby and H2 % concentration at breather tube out is correlated with test for a baseline case. A good correlation within 5% is observed between experiment and simulation. The study helped engine program to complete the optimization and design verification through simulation and get the best concept implemented. Keywords: ICE – Internal combustion engine, CFD – Computational fluid dynamics, H2 - Hydrogen