Hydrogen Flame Propagation from a Variable Volume Combustion Chamber in a Narrow Moving Annular Gap

We have considered the use of a 3D mathematical model based on fundamental Navier-Stokes differential equations describing the turbulent motion of a chemically reacting gas, the flame propagation process and the associated problem of local unsteady heat transfer in a narrow gap located between the piston and the cylinder above the upper compression ring. The conditions of extinguishing and flame propagation in the gap has been established, which significantly affects the thermal boundary condition used to simulate the heat-stressed state of the piston and cylinder liner. This task is especially relevant when converting serial, traditional internal combustion engines (ICE) into a hydrogen engine. It is shown that by changing the composition of the combustible mixture (hydrogen-air), it is possible to control the process of hydrogen flame propagation in the gap, thereby reducing heat losses in a hydrogen engine.