Effect of eddy diffusivity on turbulent film condensation outside a horizontal tube

• Autorzy: Yang S. , Lin Y.
• Języki publikacji: EN

Abstrakty

EN

The effect of eddy diffusivity upon the turbulent film condensation of saturated vapour flowing downward onto a horizontal isothermal circular tube is performed theoretically by employing the Hilpert semi-empirical model. The interfacial shear of the vapour from laminar flow to turbulent flow is evaluated with help of potential flow theory. The transition region or the separation point of condensate film is also studied for the following different dominant parameters including Prandtl number, Reynolds number, sub-cooling parameters and system pressure parameter. The condensate film flow and the heat transfer characteristics under the effects of eddy diffusivity and the above mentioned parameters are investigated. The present result shows in better agreement with the experimental data than the previous theoretical modes do.

Słowa kluczowe

EN

eddy diffusivity effect; film condensation; horizontal tube; turbulent

PL

rury poziome; turbulencje

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2006
• Tom: Vol. 27, no. 1
• Strony: 75--87
• Opis fizyczny: Wykr., wz.,Bibliogr. 12 poz.,

Twórcy

autor

Yang S.

autor

Lin Y.

• Department of Mold and Die Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan

Bibliografia

• [1] NUSSELT W.: Film condensation of steam, Zeitschrift des vereines deutsher Ingenieure, Vol.60, 1916, 541-546 (in German).
• [2] SHEKRILADZE I.G., AND GOMELAURI V.I.: Theoretical study of laminar film condensation of flowing vapor, Int. J. Heat Mass Transfer, Vol. 9, 1966, 581-591.
• [3] ROSE J .W.: E ect of pressure gradient in forced film condensation on a horizontal tube-e ect of surface temperature variation, Int. J. Heat Mass Transfer, Vol.27, 1984, 39-47.
• [4] HSU C. H. AND YANG S.A.: Pressure gradient and variable wall temperature e ects during film wise condensation from downward flowing vapor onto a horizontal tube, Int .J. Heat and Mass Transfer, Vol.42, 1999, 2419-2426.
• [5] SARMA P. K., VIJAYALAKSHMI B., MAYINGER F., AND KAC S.: Turbulent film condensation on a horizontal tube with external flow of pure vapors, Int. J. Heat Mass Transfer, Vol.41, 1998, 537-545.
• [6] KATO, H., NISHIWAKI N. AND HIRATA M.: On the turbulent heat transfer by free convection from a verticalplate, Int. J. Heat Mass Transfer, Vol.11, 1967, 1117-1125.
• [7] HOMESCU D. AND PANDAY P.K.: Forced convection condensation on a horizontal tube: influence of turbulence in the vapor and liquid phases J. Heat Transfer, Vol.121, 1999, 874-885.
• [8] FLETCHER R.H.; Prediction of transpired turbulent boundary layers, J. of Heat Transfer, 1974, 89-94.
• [9] MICHAEL A.G., ROSE J.W., AND DANIELS L.C.: Forced convection condensation on a horizontal tube-experimental with verticaldown flow of steam, J. of Heat Transfer, Vol.111, 1989, 792-797.
• [10] HONDA H., NOZU S., UCHIMA B. AND FUJII T.; Efect of vapor velocity on film condensation of R -113 on horizontal tubes in a crossflow, Int. J. Heat Mass Transfer, Vol.29, 1986, 429-438.
• [11] INCROPERA, F. P., AND DEWITT, D. P.; The cylinder in cross flow, [in:] Introduction to Heat Transfer, 2nd ed., Vol.7, Wiley, New York 1990, 380-381.
• [12] BEJAN A.: Turbulent boundary layer flow, [in:] Convection Heat Transfer, 2nd ed., Wiley, Vol.7, New York, 1995, 293-324.