Experimental Investigations of Spray Characteristics of a Pressure-Swirl Atomizer

Abstract

Spray characteristics of a pressure-swirl atomizer are investigated using high-speed shadowgraph technique under different pressure drops (ΔP) and fuel temperatures (T). An image processing method is developed using MATLAB. The results illustrate that the mass flow rate climbs with the increase of ΔP, while the discharge coefficient (C_d) decreases firstly and then climbs with the increase of ΔP. ΔP has larger effect on the cone angle relative to fuel temperature. With the increase of ΔP, the shape of liquid film changes from ‘onion’ to ‘tulip’ and finally be fully developed spray cone. Meanwhile, the surface of liquid film becomes smoother with the increase of ΔP. The average breakup length climbs, then decreases to nearly a constant value with the increase of ΔP, which is induced by the “Impact wave,” surface wave, and turbulent energy. There are little differences on the shape of the liquid film under different temperatures, and temperature has different influence on breakup length under different ΔP. Both the fuel temperature and ΔP have significant impact on the surface wavelength (λ) and velocities (U, V) of surface wave. The width of fuel stream becomes larger with the increase of ΔP and fuel temperature. The results can further deepen the understanding of spray characteristics of pressure-swirl atomizer.

Keywords

Pressure-swirl atomizer liquid film breakup high-speed shadowgraph technique

Get full access to this article

View all access options for this article.

References

Lasheras

Villermaux

Hopfinger

. Break-up and atomization of a round water jet by a high-speed annular air jet. J Fluid Mech 1998; 357: 351–379.

Engelbert

Hardalupas

Whitelaw

. Breakup phenomena in coaxial airblast atomizers. Proc Math Phys Sci 1995; 451: 189–229.

Lin

Reitz

. Drop and spray formation from a liquid jet. Ann Rev Fluid Mech 1998; 30: 85–105.

Zhao

Liu

H F

Tian

, et al. Influence of atomizer exit area ratio on the breakup morphology of coaxial air and round water jets. AIChE J 2014; 60: 2335–2345.

Ding

. The instability and droplet size distribution of liquid-liquid coaxial swirling spray: An experimental investigation. Exp Therm Fluid Sci 2017; 82: 166–173.

Liu

Yang

, et al. Experimental investigations of spray generated by a pressure swirl atomizer. J Energy Inst 2018; 92: 210–221.

Rong

Ruan

Liu

, et al. Experimental study of liquid nitrogen spray characteristics in atmospheric environment. Appl Therm Eng 2018; 142: 717–722.

Ramamurthi

Tharakan

. Experimental study of liquid sheets formed in coaxial swirl injectors. J Propul Power 2015; 11: 1103–1109.

Santolaya

Calvo

Cerecedo

. Experimental study of near-field flow structure in hollow cone pressure swirl sprays. J Propul Power 2012; 23: 382–389.

10.

Reddy

Mishra

. Studies on spray behavior of a pressure swirl atomizer in transition regime. J Propul Power 2012; 24: 74–80.

11.

Kim

Koh

, et al. Effect of ambient gas density on spray characteristics of swirling liquid sheets. J Propul Power 2012; 23: 603–611.

12.

Kim

Han

, et al. Effect of recess on the spray characteristics of liquid–liquid swirl coaxial injectors. J Propul Power 2012; 23(6): 1194–1203.

13.

Hamid

Atan

. Spray characteristics of jet–swirl nozzles for thrust chamber injector. Aerosp Sci Technol 2009; 13: 192–196.

14.

Kalitan DM, Salgues D, Mouis AG, et al. Experimental liquid rocket swirl coaxial injector study using nonintrusive optical techniques. In: 41st AIAA/ASME/SAE/ASEE joint Propulsion Conference, Tucson, Arizona, 10–13 July 2005, paper no. AIAA 2005–4299.

15.

Thompson

Rothstein

. The atomization of viscoelastic fluids in flat-fan and hollow-cone spray nozzles. J Non Newton Fluid Mech 2007; 147: 11–22.

16.

Garai

Pal

Mondal

, et al. Experimental investigation of spray characteristics of kerosene and ethanol-blended kerosene using a gas turbine hybrid atomizer. Sādhanā 2017; 42: 1–13.

17.

Atkins

Ervin

Shafer

. Experimental studies of jet fuel viscosity at low temperatures, using a rotational viscometer and an optical cell. Energy Fuels 2005; 19: 1935–1947.

18.

Coordinating Research Council. Handbook of aviation fuel properties. Coordinating Research Council TR-635, Atlanta, GA, 2004.

19.

Caines BN, Hicks RA and Wilson CW. Influence of sub-atmospheric conditions on the performance of an air-blast atomizer. In: 37th AIAA/ASME/SAE/ASEE joint propulsion conference, Salt Lake City, UT, 8–11 July 2001.

20.

Read

Rogerson

Hochgreb

. Flame imaging of gas turbine relight. AIAA J 2010; 48: 1916–1927.

21.

Ochowiak

Matuszak

Włodarczak

, et al. The concept design and study of twin-fluid effervescent atomizer with air stone aerator. Chem Eng Process Process Intensif 2018; 124: 24–28.

22.

Liu C, Liu F, Yang J, et al. Experimental investigation of spray and combustion performances of a fuel-staged low emission combustor part i: effects of main swirl angle. In: Proceedings of the ASME turbo expo 2016: turbomachinery technical conference and exposition, Seoul, South Korea, 13–17 June 2016.

23.

Surya Prakash

Gadgil

Raghunandan

. Breakup processes of pressure swirl spray in gaseous cross-flow. Int J Multiphase Flow 2014; 66: 79–91.

24.

Zhongtao Kang, Zhen-guo Wang, Qinglian Li, et al. Breakup of conical liquid film with and without coaxial gas flow. In: 18th Annual conference on liquid atomization and spray systems – Asia, Chennai, India, 6–9 November 2016.