Comparison Between Two Droplet Heating Models Under Diesel Spray-Like Conditions

A numerical study which compares between the diffusion limit (DL) and the well mixed (WM) droplet heating models under diesel combustion conditions is presented. The CFD code KIVA-II is used to perform the computations. Predictions are compared with available experimental data in n-decane and n-heptane sprays. For the n-decane spray measured gas temperatures support employing the DL-model, and as compared with the DL-model the WM-model clearly yields underpredicted vapor concentrations. In the n-heptane spray vapor concentration predictions show a strong independency of the employed heating model, and generally are in a good agreement with the measurements. Based on this independency, in subsequent comparisons between the two models under different spray operating conditions only the fuel with the lower volatility (n-decane) is considered.