The experimental study on the viscosity effect on the discharge coefficient for effervescent atomizers

•The value of CD is decreases with increasing viscosity.•The effect of viscosity is higher for smaller values of GLR.•At values of GLR above 0.1 the effect of viscosity on discharge coefficient is negligible.

This paper draws a link between the liquid viscosity and the discharge coefficient for effervescent atomization. The experimental data shows that CD is a non-linear function of GLR, with value decreasing rapidly as GLR is increased from zero to around 0.07 and thereafter decreasing at a slower rate with further increase in GLR. Discharge coefficient depends on liquid viscosity. Mean drop size strongly depends on liquid viscosity and increases markedly with an increase in viscosity. The results obtained for CD and SMD are connected with character of flow and atomization mechanism. Mathematical analysis shows that CD depends on the shear viscosity in the power of −0.0475 and GLR in power of −0.80.