The effect of angle of attack on heat transfer characteristics of drop-shaped tube

An experimental investigation has been conducted to clarify heat transfer characteristics and flow behaviors around an elliptic cylinder. Also, flow visualization was carried out to clarify the flow patterns around the cylinder. The elliptic cylinder examined has an axis ratio of 1:2.17, was placed in the focus of parabolic plate. The test fluid is air and the Reynolds number based on the major axis length, c, ranged from 5 x 103 to 3 x 104. The angle of attack (?) was changed from 0? to 90? at 15? interval. It is found that the pressure distribution, form drag, location of separation point, and heat transfer coefficient depend strongly upon the angle of attack. Over the Reynolds number range examined, the mean heat transfer coefficient is at its highest at ? = 60? - 90?. The values of heat transfer coefficient in the case of free cylinder are higher than those for cylinder/plate combination at all angles of attack and Reynolds number range examined.

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Analysis On Heat Transfer Characteristics For Bosh Copper Cooling Stave With Shaped Tube

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/439/2/022003 ◽

2018 ◽

Vol 439 ◽

pp. 022003

Author(s):

Ye Huo ◽

Liang-yu Chen

Keyword(s):

Heat Transfer ◽

Heat Transfer Characteristics ◽

Transfer Characteristics ◽

Shaped Tube

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The Effect of the Corrugation Rib Angle of Attack on the Fluid Flow and Heat Transfer Characteristics Inside Corrugated Ribbed Passage

Journal of Heat Transfer ◽

10.1115/1.4003668 ◽

2011 ◽

Vol 133 (8) ◽

Cited By ~ 4

Author(s):

A. M. I. Mohamed ◽

R. Hoettiba ◽

A. M. Saif

Keyword(s):

Heat Transfer ◽

Fluid Flow ◽

Heat Transfer Enhancement ◽

Angle Of Attack ◽

Navier Stokes ◽

Transfer Enhancement ◽

Heat Transfer Characteristics ◽

Transfer Characteristics ◽

Flow And Heat Transfer ◽

Flow Field Characteristics

Heat transfer enhancement using corrugated ribbed passages is one of the common enhancement techniques inside heat exchangers. The present study investigated numerically the effect of the corrugation rib angle of attack on the fluid flow and heat transfer characteristics inside the corrugated ribbed passage. The commercial computational fluid dynamics code PHOENICS 2006 was used to perform the numerical analysis by solving the Navier–Stokes and energy equations. The experimental part of this study was used only to validate the numerical model, and a good agreement between the experimental results and the model was obtained. The flow field characteristics and heat transfer enhancement were numerically investigated for different corrugated rib angles of attack as follows: 90 deg, 105 deg, 120 deg, 135 deg, and 150 deg. The corrugation rib angle of attack has a great effect on the reversed flow zone, the flow reattachments, and the enhancement of the heat transfer coefficient through the duct. The recommended rib angle of attack, which gives the optimum thermohydraulic performance, is found to be between 135 deg and 150 deg. The value of the maximum thermohydraulic performance is about 3.6 for the 150 deg rib angle of attack at a Reynolds number equal to 10,000.

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The effects of the axis ratio on the flow and heat transfer characteristics around a drop-shaped tube

Journal of Physics Conference Series ◽

10.1088/1742-6596/2057/1/012001 ◽

2021 ◽

Vol 2057 (1) ◽

pp. 012001

Author(s):

R Deeb ◽

D V Sidenkov

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Pressure Coefficient ◽

Maximum Velocity ◽

Computational Domain ◽

Heat Transfer Characteristics ◽

Axis Ratio ◽

Transfer Characteristics ◽

Flow And Heat Transfer ◽

Shaped Tube

Abstract Flow and heat transfer characteristics around single drop-shaped tubes with different axis ratio (L/D) in cross-flow are studied numerically for values of Reynolds number in the range 1.3×103 to 20×103. The results are obtained using the commercial software ANSYS Fluent for a two-dimensional (2D) computational domain. The axis ratio of the studied tubes is varied from 1 to 4, when L/D =1, the tube is circular. The simulation results agree well with the available literature. The distribution of local coefficients of pressure and friction over half of the tube’s surface is plotted and analysed. It found that the drop-shaped tubes delay the separation of the boundary layer from the tube wall. The results confirm that the minimum value of pressure coefficient decreases as L/D decreases, and the maximum value of the friction coefficient gradually increases with the growth of L/D. The result of the numerical simulation indicates the superior overall performance of drop-shaped tube with L/D=4 over the rest of the tubes. Correlations of the average Nusselt number and the friction factor in terms of Reynolds number, calculated by the maximum velocity in the minimum free cross-section, and axis ratios for the studied cases are proposed.

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