Abstract
Solution precursors have been injected into the plasma gases to produce finely structured ceramic coatings with nano- and sub-micrometric features. The trajectory history and heat and mass transfer within individual solution droplets play a very important role in determining the coating microstructure. A mathematical model is developed to analyse the thermal behavior of individual precursor droplets travelling in the high temperature plasma jet. This model involves the motion and evaporation of the precursor droplet in a DC plasma jet and the heat and mass transfer within the evaporating droplet. The influence of Stefan flow, as well as the variable thermo-physical properties of the solution and the plasma gas, is considered. The internal circulation due to the relative velocity between the droplet and the plasma jet, which may be approximated by the Hill vortex, is considered as well. The trajectory, temporal droplet surface temperature, and radius variation are predicted. The temporal temperature and concentration distributions within the evaporating droplet are presented for different injection parameters.
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Abbreviations
- A r :
-
averaging parameter
- B T, B M :
-
Spalding heat and mass transfer numbers
- C D :
-
droplet drag coefficient
- C P :
-
specific heat (J/kg·°C)
- D :
-
mass diffusivity of the vapor into the plasma (m2/s)
- L :
-
latent heat of vaporization (J/kg)
- \( {\dot{\text{m}}} \) :
-
vaporization rate (kg/s)
- m v :
-
mass fractions of vapor
- M :
-
molecular weight (kg/kmol)
- Nu :
-
Nusselt number
- P :
-
pressure (Pa)
- Pe:
-
Peclet number
- Pr:
-
Prandtl number
- Q g :
-
heat transfer from the plasma gas to drop surface (J/s)
- Q i :
-
heat conduction from droplet surface into its interior (J/s)
- r :
-
radius (m)
- Re :
-
Reynolds number
- Sh :
-
Sherwood number
- T :
-
temperature (K)
- t :
-
time (s)
- U :
-
velocity in axial direction (m/s)
- V :
-
velocity in radial direction (m/s)
- ρ:
-
density (kg/m3)
- λ:
-
thermal conductivity (w/m·k)
- μ:
-
dynamic viscosity (kg/m·s)
- g:
-
gas mixture
- l:
-
liquid
- s:
-
surface
- v:
-
vapor
- ∞:
-
far from the droplet
References
P. Fauchais, A. Vardelle, and B. Dussoubs, Quo Vadis Thermal Spraying?, J. Therm. Spray Technol., 2001, 10, p 44-66
P. Fauchais, G. Montavon, R. Lima, and B. Marple, Engineering a New Class of Thermal Spray Nano-Based Microstructures from Agglomerated Nanostructured Particles, Suspensions and Solutions: An Invited Review, J. Phys. D Appl. Phys., 2011, 44, p 1-53
J. Karthikeyan, C. Berndt, S. Reddy, J. Wang, A. King, and H. Herman, Nanomaterial Deposits Formed by DC Plasma Spraying of Liquid Feedstocks, J. Am. Ceram. Soc., 1998, 81, p 121-128
N. Padture, K. Schlichting, T. Bhatia, A. Ozturk, B. Cetegen, E. Jordan, and M. Gell, Towards Durable Thermal Barrier Coatings with Novel Microstructures Deposited by Solution-Precursor Plasma Spray, Acta Mater., 2001, 49, p 2251-2257
Y. Shan, T. Coyle, and J. Mostaghimi, Modeling the Influence of Injection Modes on the Evolution of Solution Sprays in a Plasma Jet, J. Therm. Spray Technol., 2010, 19, p 248-254
A. Ozturk and B. Cetegen, Modeling of Plasma Assisted Formation of Precipitates in Zirconium Containing Liquid Precursor Droplets, Mater. Sci. Eng. A, 2004, 384, p 331-351
A. Ozturk and B. Cetegen, Modeling of Axially and Transversely Injected Precursor Droplets into a Plasma Environment, Int. J. Heat Mass Transf., 2005, 48, p 4367-4383
L. Xie, X. Ma, E. Jordan, N. Padture, D. Xiao, and M. Gell, Deposition of Thermal Barrier Coatings Using the Solution Precursor Plasma Spray Process, J. Mater. Sci., 2004, 39, p 1639-1646
T. Chien and T. Coyle, Rapid and Continuous Deposition of Porous Nanocrystalline SnO2 Coating with Interpenetrating Pores for Gas Sensor Applications, J. Therm. Spray Technol., 2007, 16, p 886-892
T. Coyle and Y. Wang, Solution Precursor Plasma Spray of Nickel-Yittia Stabilized Zirconia Anodes for Solid Oxide Fuel Cell Application, J. Therm. Spray Technol., 2007, 16, p 898-904
T. Coyle and Y. Wang, Solution Precursor Plasma Spray of Porous La1−x Sr x MnO3 Perovskite Coatings for SOFC Cathode Application, J. Fuel Cell Sci. Technol., 2011, 8, p 021005
Y. Shan, T. Coyle, and J. Mostaghimi, 3D Modeling of Transport Phenomena and the Injection of the Solution Droplets in the Solution Precursor Plasma Spraying, J. Therm. Spray Technol., 2007, 16, p 736-743
S. Basu and B. Cetegen, Modeling of Thermo-Physical Processes in Liquid Ceramic Precursor Droplets Injected into a Plasma Jet, Int. J. Heat Mass Transf., 2007, 50, p 3278-3290
S. Basu, E. Jordan, and B. Cetegen, Fluid Mechanics and Heat Transfer of Liquid Precursor Droplets Injected into High-Temperature Plasmas, J. Therm. Spray Technol., 2008, 17, p 60-72
B. Cetegen and S. Basu, Review of Modeling of Liquid Precursor Droplets and Particles Injected into Plasmas and High Velocity Oxy-Fuel (HVOF) Flame Jets for Thermal Spray Applications, J. Therm. Spray Technol., 2009, 18, p 769-793
J. Fazilleau, C. Delbos, V. Rat, J. Coudert, P. Fauchais, and B. Pateyron, Phenomena Involved in Suspension Plasma Spraying, Part 1: Suspension Injection and Behavior, Plasma. Chem. Plasma Process., 2006, 26, p 371-391
Y. Shan, T. Coyle, and J. Mostaghimi, Numerical Simulation of Droplet Breakup and Collision in the Solution Precursor Plasma Spraying, J. Therm. Spray Technol., 2007, 16, p 698-704
C. Marchand, A. Vardelle, G. Mariaux, and P. Lefort, Modeling of the Plasma Spray Process with Liquid Feedstock Injection, Surf. Coat. Technol., 2008, 202, p 4458-4464
S. Prakash and W. Sirignano, Theory of Convective Droplet Vaporization with Unsteady Heat Transfer in the Circulating Liquid Phase, Int. J. Heat Mass Transf., 1980, 23, p 253-268
B. Abramzon and W. Sirignano, Droplet Vaporization Model for Spray Combustion Calculations, Int. J. Heat Mass Transf., 1989, 32, p 1605-1618
G.M. Faeth, Current Status of Droplet and Liquid Combustion, Prog. Energy Combust. Sci., 1977, 3, p 191-224
A. Tong and W. Sirignano, Multicomponent Droplet Evaporation in a High Temperature Gas, Combust. Flame, 1986, 66, p 221-235
M. Boulos, P. Fauchais, and E. Pfender, Thermal Plasmas Fundamentals and Applications, Plenum Press, New York and London, 1994
I. Castillo and R. Munz, Transient Modeling of Heat, Mass and Momentum Transfer of an Evaporating Cerium Nitrate Solution Droplet with a Surrounding Shell in a RF Thermal Argon-Oxygen Plasma Under Reduced Pressure, Int. J. Heat Mass Transf., 2007, 50, p 4468-4487
G. Jayanthi, S. Zhang, and G. Messing, Modeling of Solid Particle Formation During Solution Aerosol Thermolysis, Aerosol Sci. Technol., 1993, 19, p 478-490
Acknowledgments
The financial support of the National Natural Science Foundation of China (Project 50706027), the Scientific Research Foundation for the Returned Overseas Chinese Scholars, and Shanghai Leading Academic Discipline Project (Project J50501) are gratefully acknowledged.
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Shan, Y., Hu, Y. Heat and Mass Transfer Within an Evaporating Solution Droplet in a Plasma Jet. J Therm Spray Tech 21, 676–688 (2012). https://doi.org/10.1007/s11666-011-9726-x
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DOI: https://doi.org/10.1007/s11666-011-9726-x