Enhanced Heat Transfer From a Horizontal Finned Tube Situated in a Vertical Channel

1986 ◽  
Vol 108 (1) ◽  
pp. 62-69 ◽  
Author(s):  
E. M. Sparrow ◽  
M. A. Ansari ◽  
P. C. Stryker ◽  
R. Ruiz
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Free Space ◽  
Vertical Channel ◽  
Finned Tube ◽  
Geometric Parameters ◽  
Vertical Position ◽  
Heat Transfer Characteristics ◽  
Enhanced Heat Transfer ◽  
Transfer Rates

Experiments were performed to determine the heat transfer characteristics of a horizontal finned tube situated in a vertical channel which is open to the ambient at the top and bottom. The heat transfer from the finned tube is by natural convection and radiation. The response of the finned-tube heat transfer to three geometric parameters was investigated: (1) the vertical position of the tube in the channel, (2) the clearance between the fin tips and the channel walls, and (3) the height of the channel. Experiments were also carried out with the finned tube situated in free space. It was found that in-channel positioning of the finned tube gave rise to substantially higher heat transfer rates than did free-space positioning. With the finned tube situated in the channel, the heat transfer was enhanced by: (1) positioning the tube at the bottom of the channel, (2) small tip-to-wall clearances, and (3) tall channels.

An Experimental Study of Natural Convection Cooling of an Array of Heated Protrusions in a Vertical Channel in Water

1989 ◽  
Vol 111 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Y. Joshi ◽  
T. Willson ◽  
S. J. Hazard
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Power Dissipation ◽  
Three Dimensional ◽  
Vertical Channel ◽  
Steady Flows ◽  
Transfer Rates ◽  
Fluid Velocities ◽  
Convection Cooling ◽  
Flow Visualizations

An experimental investigation of steady state and transient natural convection from a column of eight in-line rectangular heated protrusions in a vertical channel in water is presented. Flow visualizations and element surface temperature measurements were carried out for several power dissipation levels in the range of 0.2–1.5 W per component and channel spacings from 6.4 to 23 mm. The three-dimensional steady flows were visualized in two mutually perpendicular planes. Average component temperatures determined from the measurements on the five fluid exposed faces were used to obtain nondimensional heat transfer rates. Heat transfer data for all channel spacings except the smallest did not differ from the measurements for an isolated surface by more than 14 percent. For the smallest spacing, the component surface temperatures increased significantly due to a reduction in the fluid velocities. Measurements and flow visualizations during the transient indicated an initial diffusive transport period, followed by the evolution of convective effects. No overshoots in component temperatures were found. Steady transport responses with selectively powered components are also examined.

Experimental Investigation of Natural Convection in Partially Divided Enclosures

1986 ◽  
Vol 108 (3) ◽  
pp. 554-559 ◽  
Author(s):  
J. G. Symons
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Experimental Investigation ◽  
Natural Convection ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Solar Collector ◽  
Heat Transfer Characteristics ◽  
Transfer Rates ◽  
Slope Direction

An experimental study has been performed on natural convective heat transfer in inclined enclosures heated from below, and with partitions running in the up-slope direction (see Fig. 1). The influence of a clearance between the partitions and the lower heated isothermal surface is considered. This problem is of particular importance in solar collector design. Heat transfer rates have been measured for Ra < 107, enclosure inclination of 0, 30, 60, and 90 deg from the horizontal, and partition end clearances ranging from zero up to half the enclosure height. A flow visualization study which covers the same range of inclinations and end clearances is also reported. It is shown that introducing a small partition end clearance has no significant effect on the flow or heat transfer rates. However, a large end clearance allows up-slope rolls to be established in the unpartitioned region of the enclosure, resulting in an increase in the heat transfer rates. The natural convective heat transfer rates are found to be independent of both partition end clearance and enclosure inclination over certain ranges of these parameters. The convective heat transfer characteristics are also shown to be related to the flow.

Effect of Insulated/Uninsulated Channel Walls on Heat Transfer From a Horizontal Finned Tube in a Vertical Channel

1987 ◽  
Vol 109 (2) ◽  
pp. 388-391 ◽  
Author(s):  
E. M. Sparrow ◽  
M. A. Ansari
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Vertical Channel ◽  
Finned Tube ◽  
Radiation Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Metallic Sheet ◽  
Rayleigh Numbers ◽  
Metal Wall

Measurements were made of the combined natural convection and radiation heat transfer from a horizontal finned tube situated in a vertical channel open at the top and bottom. In one set of experiments, both walls of the channel were heavily insulated, while in a second set of experiments, one of the insulated walls was replaced by an uninsulated metallic sheet. In general, the heat transfer coefficients were found to be lower with the metal wall in place, but only moderately. With the finned tube situated at the bottom of the channel, the differences in the heat transfer coefficients corresponding to the two types of walls were only a few percent. When the tube was positioned at the mid-height of the channel, larger differences were encountered, but in the practical range of Rayleigh numbers, the differences did not exceed 5 percent.

scholarly journals Investigation on Heat Transfer Characteristics of the H-type Finned Tube in Flue Gas with High Content of Ash

2017 ◽  
Vol 105 ◽  
pp. 4680-4684 ◽  
Author(s):  
Tao Han ◽  
Chang’an Wang ◽  
Qi Cao ◽  
Wufeng Chen ◽  
Defu Che
Keyword(s):  
Heat Transfer ◽  
Flue Gas ◽  
Finned Tube ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics
Sign in / Sign up

Export Citation Format

Share Document