Application of direct optical methods for investigation of two-phase flow characteristics

Аuthors

Batalov V. G.^*, Stepanov R. A.^**, Sukhanovsky A. N.^***

Institute of Continuous Media MechanicsRussian Akademy of Sciences Ural Branch , 1, Ak. Korolyov Str., Perm, 614013Russia

*e-mail: vbatalov@icmm.ru
**e-mail: rodion@icmm.ru
***e-mail: san@icmm.ru

Abstract

One of the important parts of gas turbine aircraft engine is nozzle. Mechanical and pneumaticalnozzles are wide spread and used for qualitative spraying of fuel. The spray should be uniform in azimuthal direction, with specified spray angle, structure and drop size distribution. Experimental study of two-phase flow characteristics in the nozzle spray is presented. It was shown that velocity field measurements by PIV (Particle Image Velocimetry) method have some specifics.The behavior of drops in a basic flow (air flow) strongly depends on the drop size. The velocities of relatively large drops with characteristic size of tens or even hundreds of microns are different from the velocity of main air flux. Whenconcentrationofsuchdropsishightheychangevelocitydistribution in the air flux.Thedropsizingwascarriedoutbydirectopticalmethodbased on pair of glare spots. Theessentialfeatureofproposedmethodisvalidationprocedure,thathelpto select pair of glare spots placed on one drop. Theprocedureofvalidationgivesnotonly reliable dataaboutdropsizesbutalso dropsvelocity distribution. Sowiththeuseofproposedmethoditispossibletostudydependencedropsvelocityontheir sizes and to reconstruct spatial distribution of flow rate. Thenumericalrealizationofproposed algorithm effectively scales for multiprocessor systems. Itrequiresonlyminimaladaptationforclustersoftware. Thispossibilityisveryimportantforanalysesofmultiplemeasurementsforrepresentativestatistics. Asaresultofourstudythesoftwarepackage "Programfordropsizinganddropsvelocitymeasurementsbytheir optical images"(sertificate of registry № 2013611440 от 09.01.2013).

Keywords:

Particle Image Velocimetry, direct method of drop sizing, two-phase flow

References

1. Rusakov S.V., Shuvaev N.V. Vychislitel’naya mekhanika sploshnykh sred, 2013, vol. 6, no. 3, pp. 300-308.
2. Sipatov A.M., Karabasov S.A., GomzikovL.Yu., Abramchuk T.V., Semakov G.N. Vychislitel’naya mekhanika sploshnykh sred, 2013. vol. 6, no. 3, pp. 346-353.
3. Brykin B.V., Evdokimov I.E. Elektronnyi zhurnal"Trudy MAI", 2012, no. 61, available at: http://www.mai.ru/science/trudy/eng/published.php?ID=35499 (accessed 24.12.2012).
4. Tropea C. Optical particle characterization in flows. Annual Review of Fluid Mechanics, 2011, doi.10.1146/annurev-fluid-121108-145442 .
5. Adrian R.J., Westerweel J. Particle Image Velocimetry. Cambridge, UK: Cambridge Univ. Press, 2010.
6. Hofeldt D.L., Hanson R.K. Instantaneous imaging of particle size and spatial distribution in two-phase flows, Appl. Opt., 1991, vol.30, pp.4936—4948.
7. Bongiovanni C., ChevallierJ.Ph., Fabre J. Sizing of bubbles by incoherent imaging: defocus bias, Exp.Fluids,1997, vol.23, pp.209—2016.
8. van de Hulst H.C, Wang RT. Glare points. Appl. Opt., 1991, vol.30, pp.4755—4763.
9. Hess C.F., L’Esperance D. Droplet imaging velocimeter and sizer: a two-dimensional technique to measure droplet size, Exp. Fluids, 2009, vol.47, pp.171—182.
10. Jermy M.C., Greenhalgh D.A. Planar dropsizing by elastic and fluorescence scattering in sprays too dense for phase Doppler measurement, Appl. Phys. B, 2000, vol.71, pp.703—710.
11. Domann R., Hardalupas Y. Spatial distribution of fluorescence intensity within large droplets and its dependence on dye concentration, 2001, Appl Opt., 2001, vol.40, pp.3586-3597.
12. Varaksin A.Yu., Polyakov A.F. Izmeritel’naiatehnika, 1998, no.8, p.22-26.
13. Aisa L., Garcia J.A., Cerecedo L.M., Garcia Palacin I., Calvo E. Particle concentration and local mass flux measurements in two-phase flows with PDA. Application to a study on the dispersion of spherical particles in a turbulent air jet. Int. J. Multiphase Flow, 2002, vol. 28, no.2, pp.310-316.
14. Semidetnov N., Tropea C. Conversion relationships for multidimensional particle sizing techniques, Meas. Sci. Technol., 2004, vol.15, pp.112—118.
15. Kuhn J., Charriere F., Colomb T., Cuche E., Montfort F., Emery Y., Marquet P., Depeursinges C. Axial subnanometer accuracy in digital holographic microscopy.Meas. Sci. Technol., 2008, vol. 19, 074007.

Download