scholarly journals A numerical model of forced convection condensation on a horizontal tube in the presence of noncondensables

2017 ◽  
Vol 891 ◽  
pp. 012138 ◽  
Author(s):  
K B Minko ◽  
G G Yankov ◽  
O O Milman ◽  
V S Krylov
Keyword(s):  
Numerical Model ◽  
Forced Convection ◽  
Horizontal Tube

Pressure Drop During Forced Convection Boiling of R-12 Under Swirl Flow

1982 ◽  
Vol 104 (4) ◽  
pp. 758-762 ◽  
Author(s):  
K. N. Agrawal ◽  
H. K. Varma ◽  
S. Lal
Keyword(s):  
Pressure Drop ◽  
Forced Convection ◽  
Flow Boiling ◽  
Horizontal Tube ◽  
Swirl Flow ◽  
Flow Data ◽  
Nelson Model ◽  
Twisted Tapes ◽  
Twist Ratio ◽  
Flow Pressure

This investigation deals with the pressure drop during forced convection boiling of R-12 under swirl flow inside a horizontal tube. Plain flow and swirl flow pressure drop data are reported for an electrically heated, horizontal, stainless steel, round test-section fitted with twisted tapes having twist ratios from 3.76 to 10.15. A correlation has been presented expressing the swirl flow boiling pressure drop in terms of the twist ratio and the plain flow boiling pressure drop calculated by the Martinelli-Nelson model. The proposed correlation predicts the swirl flow data to within ± 20 percent of the observed values.

Effect of Circumferentially Nonuniform Heating on Laminar Combined Convection in a Horizontal Tube

1978 ◽  
Vol 100 (1) ◽  
pp. 63-70 ◽  
Author(s):  
S. V. Patankar ◽  
S. Ramadhyani ◽  
E. M. Sparrow
Keyword(s):  
Heat Transfer ◽  
Secondary Flow ◽  
Forced Convection ◽  
Horizontal Tube ◽  
Nonuniform Heating ◽  
Convection Flow ◽  
Nusselt Numbers ◽  
Wide Range ◽  
Bottom Heating ◽  
Over The Top

An analytical study has been made of how the circumferential distribution of the wall heat flux affects the forced/natural convection flow and heat transfer in a horizontal tube. Two heating conditions were investigated, one in which the tube was uniformly heated over the top half and insulated over the bottom, and the other in which the heated and insulated portions were reversed. The results were obtained numerically for a wide range of the governing buoyancy parameter and for Prandtl numbers of 0.7 and 5. It was found that bottom heating gives rise to a vigorous buoyancy-induced secondary flow, with the result that the average Nusselt numbers are much higher than those for pure forced convection, while the local Nusselt numbers are nearly circumferentially uniform. A less vigorous secondary flow is induced in the case of top heating because of temperature stratification, with average Nusselt numbers that are substantially lower than those for bottom heating and with large circumferential variations of the local Nusselt number. The friction factor is also increased by the secondary flow, but much less than the average heat transfer coefficient. It was also demonstrated that the buoyancy effects are governed solely by a modified Grashof number, without regard for the Reynolds number of the forced convection flow.

Forced-Convection Condensation over A Horizontal Tube from Mixture of Steam and A Large Amount of Air

2002 ◽  
Vol 2002 (0) ◽  
pp. 431-432
Author(s):  
Takashi SUZUKI ◽  
Koshi MITACHI ◽  
Yukihiro AIZAWA ◽  
Toru NINOMIYA
Keyword(s):  
Forced Convection ◽  
Horizontal Tube

Combined free and forced convection in a constant temperature horizontal tube

AIChE Journal ◽  
1961 ◽  
Vol 7 (1) ◽  
pp. 38-41 ◽  
Author(s):  
T. W. Jackson ◽  
J. M. Spurlock ◽  
K. R. Purdy
Keyword(s):  
Forced Convection ◽  
Constant Temperature ◽  
Horizontal Tube ◽  
Free And Forced Convection

An Interferometric Study of Combined Free and Forced Convection in a Horizontal Isothermal Tube

1981 ◽  
Vol 103 (2) ◽  
pp. 249-256 ◽  
Author(s):  
W. W. Yousef ◽  
J. D. Tarasuk
Keyword(s):  
Nusselt Number ◽  
Free Convection ◽  
Forced Convection ◽  
Average Nusselt Number ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Horizontal Tube ◽  
Reynolds Numbers ◽  
Nusselt Numbers ◽  
Free And Forced Convection

A Mach-Zehnder interferometer was employed to determine the three-dimensional temperature field, and the circumferential and average Nusselt numbers for laminar flow of air in the entrance region of an isothermal horizontal tube where the velocity and the temperature profiles were developing simultaneously. The influence of free convection due to buoyancy on forced convection heat transfer was investigated. The Reynolds numbers ranged from 120 to 1200, the Grashof numbers ranged from 0.8 × 104 to 8.7 × 104, and the ratio L/D was varied from 6 to 46. The free convection increases, substantially, the average Nusselt number, by up to a factor of 2.0 from the analytical predictions, which account for forced convection only, near the tube inlet. Far from the tube inlet the free convection tends to decrease the average Nusselt number below the analytical predictions.

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