Turbulence During the Compression Stroke

Normally diesel combustion simulations are started from bottom dead centre before combustion. Initial values of pressure and temperature are taken from experimental results or 1D-simulations. As initial turbulence values (k and ε), some correlation, intake flow simulation or just best practise values are used. All those values are initialized to be constant for whole simulation volume. In the previous study intake channel simulations were done. Authors found that the level of turbulence values at TDC were different if the intake stroke was simulated or if average values were initialized at IVC. In this paper three different engines are simulated. For each engine intake and compression strokes are simulated to get the best possible knowledge about the real turbulence values. From those results the average values of p, T, k, ε and swirl number at IVC are captured and used as initial values of compression simulation. Finally better method to initialize turbulence values is described and tested