Heat and Mass Transfer

, Volume 31, Issue 5, pp 339–346 | Cite as

Transient combustion of a heating droplet in a gravitational environment

  • L. W. Huang
  • C. H. Chen


The transient combustion characteristics of a droplet suddenly exposed to the envelope flames in an atmospheric environment are studied numerically. Combustion can be divided into a droplet heating-up and a constant-droplet-temperature burning. The naturally-convective flow is not knowna priori, but provided as part of the solution. During the heating-up stage, the temperature and evaporation rate of droplet increase sharply, and the square of diameter decreases slightly as time proceeds. In the following stage, the droplet temperature remains constant, the evaporation rate and droplet diameter decrease with time. The flowfield of natural convection is also presented to demonstrate its interaction with the flame and the transient process. Finally, the fuel accumulation phenomenon is identified and it results in an reduction of evaporation constant.


Natural Convection Evaporation Rate Fuel Accumulation Transient Process Atmospheric Environment 
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Instationäre Erwärmung eines sich erwärmenden Tröpfchens in einem Schwerkraftfeld


Der instationäre Verbrennungsprozeß eines plötzlich einem Flammenfeld in atmosphärischer Umgebung ausgesetzten Tröpfchens wird numerisch untersucht. Die Verbrennung läßt sich in die zwei Phasen unterteilen: (1) Aufheizphase des Tröpfchens, (2) konstante Tröpfchentemperatur. Die natürliche Konvektionsströmung ist nicht von vorneherein bekannt, sie wird als Teil der Lösung bereitgestellt. Während der Aufheizphase steigen Temperatur und Verdampfungstrate des Tröpfchens stark an, während das Quadrat des Durchmessers langsam abnimmt. In der folgenden Phase verringern sich Verdampfungstrate und Tröpfchendurchmesser mit der Zeit. Das Strömungsfeld imfolge natürlicher Konvektion wird ebenfalls ermittelt, um seince Wechsel-wirkung mit der Flamme und dem Verbrennungsprozeß zu veranschaulichen. Schließlich läßt sich zeigen, daß in der Umgebung des Tröpfchens eine Anhäufung unverbrannten Brenngases erfolgt, was zu einer Abnahme der Verdampfungs-rate führt.


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  1. 1.
    Williams, A.: Combustion of droplet of liquid fuel: a review. Combust. Flame 21 (1973) 1–31Google Scholar
  2. 2.
    Faeth, G.M.: Current status of droplet and liquid combustion. Progress Energy Combust. Sci. 3 (1977) 1191–1224Google Scholar
  3. 3.
    Law, C.K.: Recent advances in droplet vaporization and combustion. Progress Energy Combust. Sci. 8 (1982) 171–201Google Scholar
  4. 4.
    Crespo, A.;Linan, A.: Unsteady effects in droplet evaporation and combustion, Combust. Sci. Technol. 11 (1975) 9–18Google Scholar
  5. 5.
    Waldman, C.H.: Theory of non-steady state droplet combustion. Proc. 15th Symp. (Int.) on Combustion. The Combustion Institute, Pittsburgh, PA (1975) 429–442Google Scholar
  6. 6.
    Bellan, J.;Summerfield, M.: Model for studying unsteady droplet combustion. AIAA 15 (1971) 234–242Google Scholar
  7. 7.
    Saitoh, T.;Yamazaki, K.;Viskanta, R.: Effect of thermal radiation on transient combustion of a fuel droplet. Thermophys. Heat Transfer 7 (1993) 94–100Google Scholar
  8. 8.
    Law, C.K.: Unsteady droplet combustion with droplet heating, Combust. Flame 26 (1976) 17–22Google Scholar
  9. 9.
    Law, C.K.;Sirignano, W.A.: Unsteady droplet combuston with droplet heating-II: conduction limit. Combust. Flame 28 (1977) 175–186Google Scholar
  10. 10.
    Law, C.K.;Chung, S.H.;Srinivasan, N.: Gas-phase quasi-steadiness and fuel vapor accumulation effects in droplet burning. Combust. Flame 38 (1980) 173–198Google Scholar
  11. 11.
    Kumagai, S.;Isoda, H.: Combustion of fuel droplets in a falling chamber. Proc. 6th Symp. (Int.) on Combustion. The Combustion Institute, Reinhold (1957) 726–731Google Scholar
  12. 12.
    Isoda, H.;Kumagai, S.: New aspects of droplet combustion. Proc 7th Symp. (Int.) on Combustion. The Combustion Institute, Butterworths (1959) 523–531Google Scholar
  13. 13.
    Kumagai, S.;Sakai, T.;Okajima, S.: Combustion of free fuel droplets in a freely falling chamber. Proc. 13th Symp. (Int.) on Combustion, The Combustion Institute, Pittsburgh (1971) 779–785Google Scholar
  14. 14.
    Fendell, F.E.; Sparnkle, M.L.; Dodson, D.S.: Thin-flame theory for a fuel droplet in slow viscous flow. Fluid Mech. Part 2 (1966) 267–180Google Scholar
  15. 15.
    Aldred, J.W.; Williams, A.: The flame structure of burning spheres of liquid methanol. Combust. Flame 13 (19969) 559–562Google Scholar
  16. 16.
    Dwyer, H.R.;Sanders, B.R.: A detailed study of burning fuel droplets. Proc. 21st Symp. (Int.) on Combustion. The Combustion Institute, Pittsburgh (1986) 633–639Google Scholar
  17. 17.
    Dwyer, H.R.;Sanders, B.R.: Calculations of unsteady reacting droplet flows. Proc. 22nd Symp. (Int.) on Combustion. The Combustion Institute, Pittsburgh (1988) 1923–1929Google Scholar
  18. 18.
    Huang, L.W.;Chen, C.H.: Single droplet combustion in a gravitational environment. Wärme- Stoffübertragung 29 (1994) 415–423Google Scholar
  19. 19.
    Westbrook, C.K.;Dryer, F.L.: Simplified reaction mechanisms for oxidation of hydrocarbon fuel in flames. Combus. Sci. Technol. 27 (1981) 31–43Google Scholar
  20. 20.
    Chen, C.H.;Hou, W.H.: Diffusion flame stabilization and extinction under naturally convective flows. Combust. Flame 83 (1991) 309–324Google Scholar
  21. 21.
    Reid, R.C.;Prausnitz, J.M.;Poling, B.E.: The Properties of Gases & Liquids. Singapore: McGraw-Hill 1988Google Scholar
  22. 22.
    Thomas, P.D.;Middecoff, J.H.: Direct control of the grid point distribution in meshes generates by elliptic equations. AIAA 18 (1980) 652–656Google Scholar
  23. 23.
    Van Doormaal, J.P.;Raithby, G.D.: Enhancements of the simple method for predicting incompressible fluid flows. Numer. Heat Transfer 7 (1984) 147–163Google Scholar
  24. 24.
    Chen, C.H.;Huang, L.W.: Heat transfer for fluid flow past an isothermal heated sphere. Chinese Soc. Mech.Eng. R.O.C. 14 (1993) 200–206Google Scholar
  25. 25.
    Kanury, A.M.: Introduction to Combustion Phenomena. New York: Gordon and Breach 1975Google Scholar
  26. 26.
    Okajima, S.;Kumagai, S.: Experimental studies on combustion of fuel droplets inflowing air under zero- and high-gravity conditions. The 19th Symp. (Int.) on Combustion. The Combustion Institute, Pittsburgh (1982) 1021–1027Google Scholar
  27. 27.
    Godsave, G.A.E.: Studies of the combustion of drops in a fuel spray — the burning of single drops of fuel. Proc. 4th Symposium (Int.) on Combustion. Baltimore, Williams and Wilkins (1953) 818–830Google Scholar
  28. 28.
    Wise, H.; Lorell, J.; Wood, B.J.: The effects of chemical and physical parameters on the burning rate of a liquid droplet. Proc. 5th Symp. (Int.) on Combustion, Reinhold (1955) 132–141Google Scholar
  29. 29.
    Mawid, M.;Aggarwal, S.K.: Analysis of transient combustion of a multicomponent liquid fuel droplet. Combust. Flame 84 (1991) 197–209Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • L. W. Huang
    • 1
  • C. H. Chen
    • 1
  1. 1.Department of Mechanical EngineeringNational Chiao Tung UniversityTaiwan 30050 Republic of China

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