To obtain the high power output per unit of weight required for transportation service of all types of necessitates engine operation at high rotative speeds.
As long as engine rotative spreads do not become high (1000 to 2000 RPN) the combustion is fairly satisfactory.
However, at higher engine speeds a greater velocity of fuel injection is required and the time lag between injection and ignition becomes a greater percent of the engine cycle.
The intermittent turbulence could have a great impact on engine heat transfer because of the transitional turbulence effect.
Engine 3D CFD model further proves the existence of transitional turbulence flow.