## THERMAL SCIENCE

International Scientific Journal

### INFLUENCE OF RADIATIVE HEAT AND MASS TRANSFER MECHANISM IN SYSTEM WATER DROPLET-HIGH-TEMPERATURE GASES ON INTEGRAL CHARACTERISTICS OF LIQUID EVAPORATION

**ABSTRACT**

Physical and mathematical (system of differential equations in private derivatives) models of heat and mass transfer were developed to investigate the evaporation processes of water droplets and emulsions on its base moving in high-temperature (more than 1000 K) gas flow. The model takes into account a conductive and radiative heat transfer in water droplet and also a convective, conductive and radiative heat exchange with high-temperature gas area. Water vapors characteristic temperature and concentration in small wall-adjacent area and trace of the droplet, numerical values of evaporation velocities at different surface temperature, the characteristic time of complete droplet evaporation were determined. Experiments for confidence estimation of calculated integral characteristics of processes under investigation - mass liquid evaporation velocities were conducted with use of cross-correlation recording video equipment. Their satisfactory fit (deviations of experimental and theoretical velocities were less than 15%) was obtained. The influence of radiative heat and mass transfer mechanism on characteristics of endothermal phase transformations in a wide temperature variation range was established by comparison of obtained results of numerical simulation with known theoretical data for “diffusion” mechanisms of water droplets and other liquids evaporation in gas.

**KEYWORDS**

PAPER SUBMITTED: 2014-07-16

PAPER REVISED: 2015-01-18

PAPER ACCEPTED: 2015-01-20

PUBLISHED ONLINE: 2015-01-24

**THERMAL SCIENCE** YEAR

**2015**, VOLUME

**19**, ISSUE

**Issue 5**, PAGES [1541 - 1552]

- Ranz, W. E., Marshall, W. R., Evaporation from Drops - I, II, Chemical Engineering Progress, 48 (1952), pp. 141-146, pp. 173-180.
- Fuchs, N. A., Evaporation and Droplet Growth in Gaseous Media, Pergamon Press, London, 1959.
- Terekhov, V. I., et al., Heat and Mass Transfer in Disperse and Porous Media Experimental and Numerical Investigations of Nonstationary Evaporation of Liquid Droplets, Journal of Engineering Physics and Thermophysics, 83 (2010), 5, pp. 883-890.
- Sazhin, S. S., et al., Models for Droplet Transient Heating: Effects on Droplet Evaporation, Ignition, and Break-up, International Journal of Thermal Sciences, 44 (2005), pp. 610-622.
- Stefanović, P., et al., Numerical Modeling of Disperse Material Evaporation in Axisymmetric Thermal Plasma Reactor, Thermal Science Journal, 7 (2003), 1, pp. 63-100.
- Morales-Ruiz, S., et al., Numerical Resolution of the Liquid-Vapour Two-Phase Flow by Means of the Two-Fluid Model and a Pressure Based Method, International Journal of Multiphase Flow, 43 (2012), pp. 118-130.
- Fedorets, A. A., et al., Coalescence of a Droplet Cluster Suspended Over a Locally Heated Liquid Layer, Interfacial Phenomena and Heat Transfer, 1 (2013), 1, pp. 51-62.
- Shanthanu, S., et al., Transient Evaporation of Moving Water Droplets in Steam - Hydrogen - Air Environment, International Journal of Heat and Mass Transfer, 64 (2013), pp. 536-546.
- Gatapova, E. Ya., et al., Evaporation of a Sessile Water Drop on a Heated Surface with Controlled Wettability, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 441 (2014), pp. 776-785.
- Zeng, Y., Lee, C. F., A Model for Multicomponent Spray Vaporization in a High-Pressure and High-Temperature Environment, Journal of Engineering for Gas Turbines and Power, 124 (2002), pp. 717-724.
- Varaksin, A. Yu., Fluid Dynamics and Thermal Physics of Two-Phase Flows: Problems and Achievements, High Temperature, 51 (2013), 3, pp. 377-407.
- Volkov, R. S., et al., Experimental Study of the Change in the Mass of Water Droplets in Their Motion through High-Temperature Combustion Products, Journal of Engineering Physics and Thermophysics, 86 (2013), 6, pp. 1413-1418.
- Kuznetsov, G. V., Strizhak, P. A., The Motion of a Manifold of Finely Dispersed Liquid Droplets in the Counterflow of High-Temperature Gases, Technical Physics Letters, 40 (2014), 6, pp. 519-522.
- Volkov, R. S., et al., Influence of the Initial Parameters of Spray Water on Its Motion through a Counter Flow of High Temperature Gases, Technical Physics, 59 (2014), 7, pp. 959-967.
- Avdeev, A. A., Zudin, A. A., Kinetic Analysis of Intensive Evaporation (Method of Reverse Balances), High Temperature, 50 (2012), 4, pp. 527-535.
- Vysokomornaya, O. V., et al., Heat and Mass Transfer in the Process of Movement of Water Drops in a High-Temperature Gas Medium, Journal of Engineering Physics and Thermophysics, 86 (2013), 1, pp. 62-68.
- Kuznetsov, G. V., Strizhak, P. A., Numerical Investigation of the Influence of Convection in a Mixture of Combustion Products on the Integral Characteristics of the Evaporation of a Finely Atomized Water Drop, Journal of Engineering Physics and Thermophysics, 87 (2014), 1, pp. 103-111.
- Glushkov, D. O., et al., Numerical Investigation of Water Droplets Shape Influence on Mathematical Modeling Results of Its Evaporation in Motion through a High-Temperature Gas, Mathematical Problems in Engineering, 2014 (2014), Article ID 920480.
- Samarskii, A. A., The Theory of Difference Schemes, Marcel Dekker, USA, 2001.
- Kuznetsov, G. V., Strizhak, P. A., On the Possibility of Using a One-Dimensional Model for Numerical Analysis of the Ignition of a Liquid Condensed Material by a Single Heated Particle, Combustion, Explosion and Shock Waves, 46 (2010), 6, pp. 683-689.
- Kuznetsov, G. V., Strizhak, P. A., Transient Heat and Mass Transfer at the Ignition of Vapor and Gas Mixture by a Moving Hot Particle, International Journal of Heat and Mass Transfer, 53 (2010), pp. 923-930.
- Raffel, M., et al., Particle Image Velocimetry, Springer, Berlin, 1998.
- Foucaut, J. M., Stanislas, M., Some Considerations on the Accuracy and Frequency Response of Some Derivative Filters Applied to Particle Image Velocimetry Vector Fields, Measurement Science and Technology, 13 (2002), 7, pp. 1058-1071.
- Damaschke, N., et al., Optical Limits of Particle Concentration for Multi-Dimensional Particle Sizing Techniques in Fluid Mechanics, Experiments in Fluids, 32 (2002), 2, pp. 143-152.
- Baehr, H. D., Stephan, K., Heat and Mass Transfer, Springer Verlag, Berlin, Deutschland, 1998.
- Glantschnig, W. J., Chen, S., Light Scattering from Water Droplets in the Geometrical Optics Approximation, Applied Optics, 20 (1981), pp. 2499-2509.
- Konig, G. et al., A New Light-Scattering Technique to Measure the Diameter of Periodically Generated Moving Droplets, J. of Aerosol Sci, 17 (1986), 2, pp. 157-167.
- Kawaguchi, T. et al., Size Measurements of Droplets and Bubbles by Advanced Interferometric Laser Imaging Technique, Meas Sci and Technol, 13 (2002), pp. 308-316.
- Kuznetsov, G. V., Strizhak, P. A. Evaporation of Single Droplets and Dispersed Liquid Flow in Motion through High Temperature Combustion Products, High Temperature, 52 (2014), 4, pp. 568-575.
- Vysokomornaya, O. V., et al., Experimental Investigation of Atomized Water Droplet Initial Parameters Influence on Evaporation Intensity in Flaming Combustion Zone, Fire Safety Journal, 70 (2014), pp. 61-70.
- Volkov, R. S., et al., The influence of Initial Sizes and Velocities of Water Droplets on Transfer Characteristics at High-Temperature Gas Flow, International Journal of Heat and Mass Transfer, 79 (2014), pp. 838-845.
- Volkov, R. S., et al., Mechanism of Liquid Drop Deformation in Subsonic Motion in a Gaseous Medium, Journal of Engineering Physics and Thermophysics, 87 (2014), 6, pp. 1351-1361.
- Volkov, R. S., et al., Analysis of the Effect Exerted by the Initial Temperature of Atomized Water on the Integral Characteristics of Its Evaporation during Motion through the Zone of "Hot" Gases, Journal of Engineering Physics and Thermophysics, 87 (2014), 2, pp. 450-458.
- Volkov, R. S., et al., Evaporation of Two Liquid Droplets Moving Sequentially through High-Temperature Combustion Products, Thermophysics and Aeromechanics, 21 (2014), 2, pp. 255-258.
- Kuznetsov, G. V., et al., Motion of Fine-Spray Liquid Droplets in Hot Gas Flow, Thermophysics and Aeromechanics, 21 (2014), 5, pp. 637-644.