The Burning Velocity in a CFR Engine with Different Turbulent Flow Fields Generated by Intake Valves

An equation has been derived to calculate the burning velocity in a CFR engine from the measured flame speed under different turbulent flow fields. The turbulence is generated during the intake stroke as the fresh charge flows through different perforated 360° shrouded intake valves. The shrouds have holes of different sizes, but of the same total flow area.

Results show that these valves decrease the cycle-to-cycle variation and produce higher burning velocities than conventional valves, particularly at higher engine speeds. The burning velocity depends on the Reynolds number as well as the turbulence scale.