Skip to main content
Log in

A novel approach for conditional measurement of droplet size distribution within droplet clusters in sprays

  • Research Article
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

A novel method for conditional measurement of droplet size distribution within droplet clusters in sprays is reported in this paper. The salient feature of this approach is the application of Voronoi analysis to droplets measured by the ILIDS technique, which is capable of providing planar measurement of size of individual droplets in a spray. The principle of the present technique is based on calculation of Voronoi tessellations around the droplets identified in the ILIDS image processing. Comparison of the distribution of areas of the Voronoi cells with that from a random distribution of droplets described by a Poisson function facilitates classification of the Voronoi cells as clusters or voids. Thus, individual clusters of droplets and void areas are recognized by identifying the interconnected cells. Since the sizes of individual droplets are known, conditional measurement of droplet size distribution within clusters and voids is possible. Since droplet images are always defocused in the ILIDS technique, correct identification of droplet centers is important, which is described in the paper. It is shown that in spite of the low validation ratio in the ILIDS image processing, the results on the cluster and void characterization agree well with those by Voronoi analysis of PIV images. The novel method is demonstrated for an air-assist spray where ILIDS measurements are obtained far downstream of the injector exit. Interestingly, the characteristic droplet size within droplet clusters is found to be smaller than that in voids, indicating size-based preferential segregation of droplets due to clustering in sprays.

Graphical abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14

Similar content being viewed by others

References

  • Akamatsu F, Miutani Y, Katsuki M, Tsushima S, Cho YD (1996) Measurement of the local group combustion number of droplet clusters in a premixed spray stream. In: Symposium (international) on combustion, vol 26, pp 1723–1729. Elsevier, London

  • Aliseda A, Cartellier A, Hainaux F, Lasheras JC (2002) Effect of preferential concentration on the settling velocity of heavy particles in homogeneous isotropic turbulence. J Fluid Mech 468:77–105

    Article  Google Scholar 

  • Balachandar S, Eaton JK (2010) Turbulent dispersed multiphase flow. Annu Rev Fluid Mech 42:111–133

    Article  Google Scholar 

  • Chen L, Goto S, Vassilicos JC (2006) Turbulent clustering of stagnation points and inertial particles. J Fluid Mech 553:143–154

    Article  MathSciNet  Google Scholar 

  • Coleman SW, Vassilicos JC (2009) A unified sweep-stick mechanism to explain particle clustering in two-and three-dimensional homogeneous, isotropic turbulence. Phys Fluids 21(11):113301

    Article  Google Scholar 

  • Damaschke N, Nobach H, Nonn TI, Semidetnov N, Tropea C (2005) Multi-dimensional particle sizing techniques. Exp Fluids 39(2):336–350

    Article  Google Scholar 

  • Ferenc J-S, Néda Z (2007) On the size distribution of poisson Voronoi cells. Phys A Stat Mech Appl 385(2):518–526

    Article  Google Scholar 

  • Ferrante A, Elghobashi S (2003) On the physical mechanisms of two-way coupling in particle-laden isotropic turbulence. Phys Fluids 15(2):315–329

    Article  Google Scholar 

  • Glover AR, Skippon SM, Boyle RD (1995) Interferometric laser imaging for droplet sizing: a method for droplet-size measurement in sparse spray systems. Appl Opt 34(36):8409–8421

    Article  Google Scholar 

  • Hardalupas Y, Taylor AMKP, Whitelaw JH (1994) Mass flux, mass fraction and concentration of liquid fuel in a swirl-stabilized flame. Int J Multiphase Flow 20:233–259

    Article  Google Scholar 

  • Hardalupas Y, Sahu S, Taylor AMKP, Zarogoulidis K (2010) Simultaneous planar measurement of droplet velocity and size with gas phase velocities in a spray by combined ILIDS and PIV techniques. Exp Fluids 49(2):417–434

    Article  Google Scholar 

  • Heinlein J, Fritsching U (2006) Droplet clustering in sprays. Exp Fluids 40(3):464–472

    Article  Google Scholar 

  • Lampa A, Fritsching U (2013) Large eddy simulation of the spray formation in confinements. Int J Heat Fluid Flow 43:26–34

    Article  Google Scholar 

  • Lian H, Charalampous G, Hardalupas Y (2013) Preferential concentration of poly-dispersed droplets in stationary isotropic turbulence. Exp Fluids 54(5):1525

    Article  Google Scholar 

  • Lian H, Soulopoulos N, Hardalupas Y (2017) Evaluation of the topological characteristics of the turbulent flow in a ‘box of turbulence’through 2D time-resolved particle image velocimetry. Exp Fluids 58(9):118

    Article  Google Scholar 

  • Maeda M, Kawaguchi T, Hishida K (2000) Novel interferometric measurement of size and velocity distributions of spherical particles in fluid flows. Meas Sci Technol 11(12):L13

    Article  Google Scholar 

  • Maeda M, Akasaka Y, Kawaguchi T (2002) Improvements of the interferometric technique for simultaneous measurement of droplet size and velocity vector field and its application to a transient spray. Exp Fluids 33(1):125–134

    Article  Google Scholar 

  • Manish M, Sahu S (2018) Analysis of droplet clustering in air-assist sprays using Voronoi tessellations. Phys Fluids 30(12)

  • Manish M, Sahu S (2019) Droplet clustering and local spray unsteadiness in air-assisted sprays. Exp Therm Fluid Sci 100:89–103

    Article  Google Scholar 

  • Maxey MR (1987) The gravitational settling of aerosol particles in homogeneous turbulence and random flow fields. J Fluid Mech 174:441–465

    Article  Google Scholar 

  • McDonell VG, Adachi M, Samuelsen GS (1992) Structure of reacting and non-reacting swirling air-assisted sprays. Combus Sci Technol 82(1–6):225–248

    Article  Google Scholar 

  • Monchaux R, Bourgoin M, Cartellier A (2010) Preferential concentration of heavy particles: a Voronoï analysis. Phys Fluids 22(10):103304

    Article  Google Scholar 

  • Monchaux R, Bourgoin M, Cartellier A (2012) Analyzing preferential concentration and clustering of inertial particles in turbulence. Int J Multiphase Flow 40:1–18

    Article  Google Scholar 

  • Obligado M, Missaoui M, Monchaux R, Cartellier A, Bourgoin M (2011) Reynolds number influence on preferential concentration of heavy particles in turbulent flows. J Phys Conf Ser 318:052015 (IOP Publishing)

    Article  Google Scholar 

  • Obligado M, Teitelbaum T, Cartellier A, Mininni P, Bourgoin M (2014) Preferential concentration of heavy particles in turbulence. J Turbul 15(5):293–310

    Article  Google Scholar 

  • Sahu S (2011) Experimental study of isothermal and evaporative sprays. PhD thesis, Imperial College London

  • Sahu S, Hardalupas Y, Taylor AMKP (2014) Simultaneous droplet and vapour-phase measurements in an evaporative spray by combined ILIDS and PLIF techniques. Exp Fluids 55(2):1673

    Article  Google Scholar 

  • Sahu S, Hardalupas Y, Taylor AMKP (2016) Droplet–turbulence interaction in a confined polydispersed spray: effect of turbulence on droplet dispersion. J Fluid Mech 794:267–309

    Article  MathSciNet  Google Scholar 

  • Sahu S, Hardalupas Y, Taylor AMKP (2018) Interaction of droplet dispersion and evaporation in a polydispersed spray. J Fluid Mech 846:37–81

    Article  MathSciNet  Google Scholar 

  • Saw EW, Shaw RA, Ayyalasomayajula S, Chuang PY, Gylfason Á (2008) Inertial clustering of particles in high-Reynolds-number turbulence. Phys Rev Lett 100(21):214501

    Article  Google Scholar 

  • Sornek RJ, Dobashi R (2000) Effect of turbulence on spatial distribution and group behavior of droplet in a spray flame. Combus Sci Technol 611(1):191–211

    Article  Google Scholar 

  • Sumbekova S, Cartellier A, Aliseda A, Bourgoin M (2017) Preferential concentration of inertial sub-Kolmogorov particles: the roles of mass loading of particles, Stokes numbers, and Reynolds numbers. Phys Rev Fluids 2(2):024302

    Article  Google Scholar 

  • Tennekes H, Lumley JL (1972) A first course in turbulence. MIT Press, Cambridge

    MATH  Google Scholar 

  • Tropea C (2011) Optical particle characterization in flows. Annu Rev Fluid Mech 43:399–426

    Article  Google Scholar 

  • Tsushima S, Saitoh H, Akamatsu F, Katsuki M (1998) Observation of combustion characteristics of droplet clusters in a premixed-spray flame by simultaneous monitoring of planar spray images and local chemiluminescence. In: Symposium (international) on combustion, vol 27, pp 1967–1974. Elsevier, London

  • Wood AM, Hwang W, Eaton JK (2005) Preferential concentration of particles in homogeneous and isotropic turbulence. Int J Multiphase Flow 31(10):1220–1230

    Article  Google Scholar 

  • Yang TS, Shy SS (2005) Two-way interaction between solid particles and homogeneous air turbulence: particle settling rate and turbulence modification measurements. J Fluid Mech 526:171–216

    Article  Google Scholar 

  • Zimmer L, Ikeda Y (2003) Simultaneous laser-induced fluorescence and mie scattering for droplet cluster measurements. AIAA J 41(11):2170–2178

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Srikrishna Sahu.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Boddapati, V., Manish, M. & Sahu, S. A novel approach for conditional measurement of droplet size distribution within droplet clusters in sprays. Exp Fluids 61, 42 (2020). https://doi.org/10.1007/s00348-019-2867-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00348-019-2867-2

Navigation