The effect of nozzle diameter, lance height and flow rate on penetration depth in a top-blown water model

This work aimed at investigating the penetration depth in a water model during lance blowing. A study of accessible literature was carried out to summarise previous work that had studied penetration depth. Based on the literature study an experimental plan was devised consisting of experiments focused on studying the effect of nozzle diameter, lance height and flow rate on the penetration depth. However, the primary focus was on studying the effect of small nozzle diameters on the penetration depth, which has not previously been reported in the literature. It was found that the results of the experiments in general agreed well with previous work, namely: the penetration depth increases with decreasing nozzle diameter, decreasing lance height and increasing gas flow rate. All equations known previously were used to calculate the penetration depth based on current experimental data. Thereafter, it was deduced which of the empirical relationships best fitted the experimental data. The jet momentum number was also determined from the experimental data and it was found that the penetration depth increased with an increased jet momentum number. However, for smaller nozzle diameters there was a considerable deviation. Therefore, a new correlation was suggested, heuristically derived from a macroscopic energy conservation consideration, and it was shown to result in better agreement between experiments and predictions for small nozzle diameters.