Skip to main content Accessibility help

Droplet–turbulence interaction in a confined polydispersed spray: effect of droplet size and flow length scales on spatial droplet–gas velocity correlations

  • S. Sahu (a1), Y. Hardalupas (a1) and A. M. K. P. Taylor (a1)


This paper discusses the interaction between droplets and entrained turbulent air flow in the far-downstream locations of a confined polydispersed isothermal spray. Simultaneous and planar measurements of droplet and gas velocities in the spray along with droplet size are obtained with the application of a novel experimental technique, developed by Hardalupas et al. (Exp. Fluids, vol. 49, 2010, pp. 417–434), which combines interferometric laser imaging for droplet sizing (ILIDS) with particle image velocimetry (PIV). These measurements quantified the spatial correlation coefficients of droplet–gas velocity fluctuations ( $R_{dg}$ ) and droplet–droplet velocity fluctuations ( $R_{dd}$ ) conditional on droplet size classes, for various separation distances, and for axial and cross-stream velocity components. At the measurement location close to the spray edge, with increasing droplet size, $R_{dg}$ was found to increase in axial direction and decrease in cross-stream direction. This suggests that as the gas-phase turbulence becomes more anisotropic away from the spray axis, the gravitational influence on droplet–gas correlated motion tends to increase. The effective length scales of the correlated droplet–gas motion were evaluated and compared with that for gas and droplet motion. The role of different turbulent eddies of the gas flow on the droplet–gas interaction was examined. The flow structures were extracted using proper orthogonal decomposition (POD) of the instantaneous gas velocity data, and their contribution on the spatial droplet–gas velocity correlation was evaluated, which quantified the momentum transfer between the two phases at different length scales of the gas flow. The droplets were observed to augment turbulence for the first three POD modes (larger scales) and attenuate it for the rest of the modes (smaller scales). It has been realized that apart from droplet Stokes number and mass loading, the dynamic range of length scales of the gas flow and the relative turbulent kinetic energy content of the flow structures (POD modes) must be considered in order to conclude if the droplets enhance or reduce the carrier-phase turbulence especially at the lower wavenumbers.


Corresponding author

Present address: Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. Email address for correspondence:


Hide All
Aliseda, A., Cartellier, A., Hainaux, F. & Lasheras, J. C. 2002 Effect of preferential concentration on the settling velocity of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 468, 77105.
Aubry, N. 1991 On the hidden beauty of the proper orthogonal decomposition. Theor. Comput. Fluid Dyn. 2, 339352.
Ayyalasomayajula, S., Gylfason, A., Collins, L. R., Bodenschatz, E. & Warhaft, Z. 2006 Lagrangian measurements of inertial particle accelerations in grid generated wind tunnel turbulence. Phys. Rev. Lett. 97, 144507.
Balachandar, S. & Eaton, J. K. 2010 Turbulent dispersed multiphase flows. Annu. Rev. Fluid Mech. 42, 111133.
Bec, J., Biferale, L., Boffetta, G., Celani, A., Cencini, M., Lanotte, A., Msacchio, S. & Toschi, F. 2006 Two-way interaction between solid particles and homogeneous air turbulence: particle settling rate and turbulence modification measurements. J. Fluid Mech. 550, 349358.
Boivin, M., Simonin, O. & Squires, K. 1998 Direct numerical simulation of turbulence modulation by particles in isotropic turbulence. J. Fluid Mech. 375, 235263.
Boree, J., Ishima, T. & Flour, I. 2001 The effect of mass loading and inter-particle collisions on the development of the polydispersed two-phase flow downstream of a confined bluff body. J. Fluid Mech. 443, 129165.
Borowsky, J. F. & Wei, T. 2011 Two-phase interactions through turbulent events as described by fluidparticle correlations. Chem. Engng Sci. 66, 128134.
Chen, C. P. & Wood, P. E. 1985 A turbulence closure model for dilute gas–particle flows. Can. J. Chem. Engng 65, 349360.
Chien, R. & Chung, J. N. 1987 Effects of vortex pairing on particle-dispersion in turbulent shear flows. Intl J. Multiphase Flow 13, 785802.
Crowe, C. T., Gore, R. A. & Troutt, T. R. 1985 Particle dispersion by coherent structures in free shear flows. Part. Science Technol. 3, 149158.
Crowe, C., Sommerfield, M. & Tsuji, Y. 1998 Multiphase Flows with Droplets and Particles. CRC Press.
Eaton, J. K. & Fessler, J. R. 1994 Preferential concentration of particles by turbulence. Intl J. Multiphase Flow 20, 169209.
Elghobashi, S. 1994 On predicting particle-laden turbulent flows. Appl. Sci. Res. 52, 309329.
Elghobashi, S. & Abou-Arab, T. W. 1983 A two-equation turbulence model for two-phase flows. Phys. Fluids 26, 931938.
Ferrand, V., Bazile, R, Boree, J. & Charnay, G. 2003 Gas-droplet turbulent velocity correlations and two-phase interaction in an axisymmetric jet laden with partly responsive droplets. Intl J. Multiphase Flow 29, 195217.
Ferrante, A. & Elghobashi, S. 2003 On the physical mechanism of two-way coupling in particle-laden isotropic turbulence. Phys. Fluids 15, 315329.
Fessler, J. R., Kulick, J. D. & Eaton, J. K. 1994 Preferential concentration of heavy particles in turbulent channel flow. Phys. Fluids 6, 37423749.
Fevrier, P., Simonin, O. & Squires, K. 2005 Partitioning of particle velocities in gas–solid turbulent flows into a continuous field and a spatially uncorrelated random distribution: theoretical formalism and numerical study. J. Fluid Mech. 533, 146.
Geiss, S., Dreizler, A., Stojanovic, Z., Chrigui, M., Sadiki, A. & Janicka, J. 2004 Investigation of turbulence modification in a non-reactive two-phase flow. Exp. Fluids 36, 344354.
Glover, A. R., Skippon, S. M. & Boyle, R. D. 1995 Interferometric laser imaging for droplet sizing: a method for droplet-size measurement in sparse spray systems. Appl. Optics 34, 84098421.
Gui, L., Wereley, S. T. & Kim, Y. H. 2003 Advances and applications of the digital mask technique in particle image velocimetry experiments. Meas. Sci. Technol. 14, 18201828.
Hardalupas, Y. & Horender, S. 2003 A method to estimate gas–droplet velocity cross correlations in sprays. Atomiz. Sprays 13, 273295.
Hardalupas, Y. & Horender, S 2010 Fluid particle correlated motion and turbulent energy transfer in a two-dimensional particle-laden shear flow. Chem. Engng Sci. 65, 50755091.
Hardalupas, Y., Sahu, S., Taylor, A. M.K. P. & 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, 417434.
Hardalupas, Y., Taylor, A. M. K. P. & Whitelaw, J. H. 1989 Velocity and particle-flux characteristics of turbulent particle-laden jets. Proc. R. Soc. Lond. 426 (1870), 3178.
Hardalupas, Y., Taylor, A. M. K. P. & Whitelaw, J. H. 1990 Velocity and size characteristics of liquid-fuelled flames stabilized by a swirl burner. Proc. R. Soc. Lond. 428 (1874), 129155.
Hardalupas, Y., Taylor, A. M. K. P. & Whitelaw, J. H. 1992 Particle dispersion in a vertical round sudden-expansion flow. Proc. R. Soc. Lond. 411442.
Hwang, W. & Eaton, J. K. 2006 Homogeneous and isotropic turbulence modulation by small heavy (ST 50) particles. J. Fluid Mech. 564, 361393.
Jong, J., Cao, L., Woodward, S., Salazar, J., Collins, L. & Meng, H. 2009 Dissipation rate estimation from PIV in zero-mean isotropic turbulence. Exp. Fluids 46, 499515.
Kavounides, C.2006 Particle flows in spray dryers. PhD thesis, Imperial College London.
Kawaguchi, T., Akasaka, Y. & Maeda, M. 2002 Size measurements of droplets and bubbles by advanced interferometric laser imaging technique. Meas. Sci. Technol. 13, 308316.
Khalitov, D. A. & Longmire, E. K. 2003 Effect of particle size on velocity correlations in turbulent channel flow. In Proceedings of the 4th ASME–JSME Joint Fluids Engineering Conference, Honolulu, Hawaii, FEDSM03-45730 .
Kiger, K. T. & Pan, C. 2002 Suspension and turbulence modification effects of solid particulates on a horizontal turbulent channel flow. J. Turbul. 3, 121.
Kulick, J. D., Fessler, J. R. & Eaton, J. K. 1994 Particle response and turbulence modification in fully developed channel flow. J. Fluid Mech. 277, 109134.
Lazaro, B. J. & Lasheras, J. C. 1992 Particle dispersion in the developing free shear layer. Part 1 unforced flow. Part 2 forced flow. J. Fluid Mech. 235, 143221.
Li, F., Qi, H. & You, C. 2010 Phase doppler anemometry measurements and analysis of turbulence modulation in dilute gas–solid two-phase shear flows. J. Fluid Mech. 663, 434455.
Longmire, E. K. & Eaton, J. K. 1992 Structure of a particle-laden round jet. J. Fluid Mech. 236, 217257.
Lumley, J. L.1967 The structure of inhomogeneous turbulent flows. In Proceedings of the International Colloqium on the Fine Scale Structure of the Atmosphere and its Influence on Radio Wave Propagation.
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, 1318.
Mashayek, F. & Taulbee, D. B. 2002 Turbulent gas–solid flows. Part II: explicit algebraic closures. Numer. Heat Transfer, Part B 41, 3152.
Monchaux, R., Bourgoin, M. & Cartellier, A. 2012 Analyzing preferential concentration and clustering of inertial particles in turbulence. Intl J. Multiphase Flow 40, 118.
Okamoto, K., Nishio, S., Saga, T. & Kobayashi, T. 2000 Standard images for particle-image velocimetry. Meas. Sci. Technol. 11, 685691.
Poelma, C., Westerweel, J. & Ooms, G. 2007 Particle–fluid interaction in grid-generated turbulence. J. Fluid Mech. 589, 315351.
Pope, S. B. 2000 Turbulent Flows. Cambridge University Press.
Prasad, A. K. & Jensen, K. 1995 Scheimpflug stereocamera for particle image velocimetry in liquid flows. Appl. Optics 34, 70927099.
Prevost, F., Boree, J., Nuclisch, H. J. & Charnay, G. 1996 Measurements of fluid/particle correlated motion in the far field of an axisymmetric jet. Intl J. Multiphase Flow 22, 685701.
Reeks, M. W. 1977 On the dispersion of small particles suspended in an isotropic turbulent fluid. J. Fluid Mech. 83, 529546.
Risso, F. & Fabre, J. 1997 Diffusive turbulence in a confined jet experiment. J. Fluid Mech. 337, 233261.
Ronneberger, O., Raffel, M. & Kompenhans, J. 1998 Advanced evaluation algorithms for standard and dual plane particle image velocimetry. In Proceedings of the 9th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, Portugal, p. 10.1.
Sahu, S.2011 Experimental study of isothermal and evapourative sprays. PhD thesis, Imperial College London.
Sakakibara, J., Wicker, R. B. & Eaton, J. K. 1996 Measurements of the particle–fluid velocity correlation and the extra dissipation in a round jet. Intl J. Multiphase Flow 22, 863881.
Simonin, O., Deutsch, E. & Minier, J. P. 1993 Eulerian prediction of the fluid/particle correlated motion in turbulent two-phase flows. Appl. Sci. Res. 51, 275283.
Sirovich, L. 1987 Turbulence and the dynamics of coherent structures, Part I, II, III. Q. Appl. Maths 45, 560590.
Squires, K. & Eaton, J. 1990 Particle response and turbulence modification in isotropic turbulence. Phys. Fluids 7, 11911203.
Sundaram, S. & Collins, L. 1999 A numerical study of the modulation of isotropic turbulence by suspended particles. J. Fluid Mech. 379, 105143.
Tanaka, T. & Eaton, J. 2010 Sub-Kolmogorov resolution partical image velocimetry measurements of particle-laden forced turbulence. J. Fluid Mech. 643, 177206.
Tennekes, H. & Lumley, J. L. 1972 A First Course in Turbulence. MIT.
Tsuji, Y., Morikawa, Y. & Shiomi, H. H. 1984 LDV measurements of an air–solid two-phase flow in a vertical pipe. J. Fluid Mech. 139, 417434.
Vance, M. W., Squires, K. D. & Simonin, O. 2006 Properties of the particle velocity field in gas–solid turbulent channel flow. Phys. Fluids 18, 063302.
Wang, L. P. & Maxey, M. R. 1993 Settling velocity and concentration distribution of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 256, 2768.
Wood, A. M., Hwang, W. & Eaton, J. K. 2005 Preferential concentration of particles in homogeneous and isotropic turbulence. Intl J. Multiphase Flow 31, 12201230.
Yang, C. Y. & Le, I. U. 1998 The role of the turbulent scales on the settling velocity of heavy particles in homogeneous isotropic turbulence. J. Fluid Mech. 371, 179205.
Yang, T. S. & Shy, S. S. 2005 Two-way interaction between solid particles and homogeneous air turbulence: particle settling rate and turbulence modification measurements. J. Fluid Mech. 526, 171216.
Zimmer, L., Domann, R., Hardalupas, Y. & Ikeda, Y. 2003 Simultaneous laser induced fluorescence and Mie scattering for droplet cluster measurements. AIAA J. 41, 21702178.
MathJax is a JavaScript display engine for mathematics. For more information see

JFM classification

Droplet–turbulence interaction in a confined polydispersed spray: effect of droplet size and flow length scales on spatial droplet–gas velocity correlations

  • S. Sahu (a1), Y. Hardalupas (a1) and A. M. K. P. Taylor (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed