• Omkar A. Yadav
• Sudhakar S. Umale
• Ashish Vajir

An orifice of pressure swirl atomizer has direct effect on its internal parameters. It is generally straight and in some cases and has a diverging section to control the spray angle. A 2-D laminar, unsteady, Volume of Fluid (VOF) model is used to numerically determine the flow parameters inside the pressure swirl atomizer. Numerical investigations were conducted on this validated model by replacing the straight section in the orifice to understand its effect onkey internal parameters such as non-dimensional liquid film thickness t*, coefficient of discharge Cd and spray angle ψ. The effect is investigated for a constant mass flow rate and the fluid chosen for atomization is water. The liquid film thickness is calculated graphically by taking volume fraction iso-surface of 0.5 and spray angle by considering the velocity distributions in the liquid sheet at the orifice exit. Non- dimensional thickness tf, was used to define the liquid sheet thickness exiting the orifice with reference to the orifice exit diameter. It was observed that Cd and ψ decrease when straight section of orifice was replaced by a diverging one. The value of tf increased due to increase in the axial velocity at the orifice exit. Maximum coefficient of discharge was achieved when, a single divergent section was used in place of combination of straight and divergent in orifice having same inlet and outlet diameters. Furthermore, when the length of the straight section L, was 0.33 times that of divergent sectionLt, the atomizer produced the lowest spray angle and non-dimensional thickness. The spray angle and non-dimensional thickness were observed to be increasing monotonically with the increase in L/Ltratio.

Atomizer, Air core, Coefficient of discharge, Spray cone angle.

"NUMERICAL INVESTIGATION ON DIVERGENT SECTION IN ORIFICE OF PRESSURE SWIRL ATOMIZER", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.302-307, June 2019, Available :http://www.jetir.org/papers/JETIR1907642.pdf

"NUMERICAL INVESTIGATION ON DIVERGENT SECTION IN ORIFICE OF PRESSURE SWIRL ATOMIZER", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp302-307, June 2019, Available at : http://www.jetir.org/papers/JETIR1907642.pdf