Effect of wall effusivity on termally induced secondary atomisation of single drop impacting onto a tilted surface

The paper reports an experimental investigation on the effects of wall effusivity and impacting angle on secondary atomisation of millimetric water drop impacting onto heated surfaces. Two materials (aluminium alloy and steel) with a large difference in effusivity were used while maintaining the same surface roughness. Impact angles between 90° (normal impact) and 6° were investigated for two wall temperatures representing two boiling regimes (bubble and film boiling). Impact morphology was observed by a high resolution camera and secondary drop size was measured by Image Analysis and Phase Doppler Anemometry.