Molecular effects on turbulent diffusion and energy in a low speed closed flow

摘要

The coefficient of turbulent diffusion and the total turbulent energy are determined during the compression phase of a motored internal combustion engine with varying flow conditions and using intake gases with varying molecular weights. These turbulent parameters change with time and with intake gas molecular weight. However, under all flow conditions, both parameters first increase and then decrease with increasing molecular weight. In addition, a direct correlation is observed between the average values of the coefficient of turbulent diffusion and the average values of the total turbulent energy, irrespective of the molecular weight.