AUGMENTATION OF HEAT TRANSFER BETWEEN FLUID STREAM AND TUBE WALL BY EMBEDDED PERFORATED BAFFLES.

Abstract In order to explore a more reasonable structure and operating parameter, guide the design and improve the gasification of seawater Open Rack Vaporizer (ORV), Research on the rules of seawater that flows and heat transfer in the ORV tube was studied in this paper. By simplifying the model, heat transfer tube model with spoiler lever was obtained and simulated, the distribution of temperature field, gas ratio, velocity field and press field in rib tube were analyzed, and different inlet velocity of LNG, roughness of the tube wall both effected on the overall gasification, the results shows that the actual gasification efficiency from heat transfer tube is higher than normal, small difference of gas ratio outlet, velocity and temperature are both lower, LNG could be easer gasified at operating temperature between -162°C~+3°C than that between -162°C~+0°C.

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Heat transfer rate for laminar, transition and turbulent boundary layer and transition phenomenon on shock tube wall

10.2514/6.1982-32 ◽

1982 ◽

Author(s):

R. DILLON, JR. ◽

H. NAGAMATSU

Keyword(s):

Heat Transfer ◽

Boundary Layer ◽

Turbulent Boundary Layer ◽

Shock Tube ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Tube Wall ◽

Transition Phenomenon

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Turbulent forced convective heat transfer inside a locally heated tube. Numerical analysis considering heat conduction within the tube wall.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.53.2528 ◽

1987 ◽

Vol 53 (492) ◽

pp. 2528-2536 ◽

Cited By ~ 2

Author(s):

Tetsu FUJII ◽

Shigeru KOYAMA ◽

Kanei SHINZATO

Keyword(s):

Heat Transfer ◽

Heat Conduction ◽

Numerical Analysis ◽

Convective Heat Transfer ◽

Convective Heat ◽

Tube Wall ◽

Heated Tube ◽

Forced Convective Heat Transfer

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Convective Heat Transfer Enhancement in a Circular Tube Using Twisted Tape

Journal of Heat Transfer ◽

10.1115/1.3122778 ◽

2009 ◽

Vol 131 (8) ◽

Cited By ~ 10

Author(s):

Zhi-Min Lin ◽

Liang-Bi Wang

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Convective Heat Transfer ◽

Heat Transfer Enhancement ◽

Secondary Flow ◽

Convective Heat ◽

Tube Wall ◽

Twisted Tape ◽

Transfer Enhancement ◽

Thermal Boundary Conditions

The secondary flow has been used frequently to enhance the convective heat transfer, and at the same flow condition, the intensity of convective heat transfer closely depends on the thermal boundary conditions. Thus far, there is less reported information about the sensitivity of heat transfer enhancement to thermal boundary conditions by using secondary flow. To account for this sensitivity, the laminar convective heat transfer in a circular tube fitted with twisted tape was investigated numerically. The effects of conduction in the tape on the Nusselt number, the relationship between the absolute vorticity flux and the Nusselt number, the sensitivity of heat transfer enhancement to the thermal boundary conditions by using secondary flow, and the effects of secondary flow on the flow boundary layer were discussed. The results reveal that (1) for fully developed laminar heat convective transfer, different tube wall thermal boundaries lead to different effects of conduction in the tape on heat transfer characteristics; (2) the Nusselt number is closely dependent on the absolute vorticity flux; (3) the efficiency of heat transfer enhancement is dependent on both the tube wall thermal boundaries and the intensity of secondary flow, and the ratio of Nusselt number with twisted tape to its counterpart with straight tape decreases with increasing twist ratio while it increases with increasing Reynolds number for both uniform wall temperature (UWT) and uniform heat flux (UHF) conditions; (4) the difference in the ratio between UWT and UHF conditions is also strongly dependent on the conduction in the tape and the intensity of the secondary flow; and (5) the twist ratio ranging from 4.0 to 6.0 does not necessarily change the main flow velocity boundary layer near tube wall, while Reynolds number has effects on the shape of the main flow velocity boundary layer near tube wall only in small regions.

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An analytical approach for optimal design of heat sinks under forced convection

Open Engineering ◽

10.2478/s13531-012-0054-9 ◽

2013 ◽

Vol 3 (2) ◽

Author(s):

Antonio Miguel

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Transfer Rate ◽

Analytical Approach ◽

Constant Heat Flux ◽

Heat Sinks ◽

Pumping Power ◽

Fluid Stream ◽

Design Standards ◽

Constant Heat

AbstractSaving energy is just as important as generating energy. In this paper, we seek an optimized structure that achieves a certain level of heat transfer rate under a minimum pumping power to drive the fluid stream. Constraints are specified by the flow regime (laminar and turbulent), admissible boundary conditions on the walls (prescribed temperature and constant heat flux), and design standards. The study will help designers with more effective basic tools for the conceptual design of system and in establishing proper operating procedures.

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