A constant heat-flux calorimeter for measuring heat transfer data

1979 ◽  
Vol 15 (8) ◽  
pp. 805-809 ◽  
Author(s):  
S. Igarashi ◽  
S. Katayama
1969 ◽  
Vol 91 (4) ◽  
pp. 511-516 ◽  
Author(s):  
G. C. Vliet

Experimental local heat transfer data are presented for natural convection on constant-heat-flux inclined surfaces using water and air. The data extend to Grz* Pr = 1016, cover angles from the vertical to 30 deg with the horizontal, and include the laminar, transition, and turbulent regimes. In the laminar regime the data correlate well with vertical plate theory when the gravitational component parallel to the surface is used. Transition is strongly affected by inclination, the transition Grz* Pr decreasing from near 1013 for vertical surfaces to approximately 108 for a surface at 30 deg to the horizontal. The turbulent local heat transfer data correlate using the actual gravity rather than the parallel component, and indicates a change in the Grz* Pr exponent from near 0 22 for a vertical surface to approximately 1/4 as the inclination decreases. The turbulent data can be correlated quite well by Nuz = 0.30(Grz* Pr)0.24.


2003 ◽  
Author(s):  
Jerry G. Myers ◽  
Sam W. Hussey ◽  
Glenda F. Yee ◽  
Jungho Kim

Investigations into single bubble pool boiling phenomena are often complicated by the difficulties in obtaining time and space resolved information in the bubble region. This usually occurs because the heaters and diagnostics used to measure heat transfer data are often on the order of, or larger than, the bubble characteristic length or region of influence. This has contributed to the development of many different and sometimes contradictory models of pool boiling phenomena and dominant heat transfer mechanisms.


2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Antonio Miguel

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.


Author(s):  
Chungpyo Hong ◽  
Yutaka Asako

Two-dimensional compressible momentum and energy equations are solved to obtain the heat transfer characteristics of gaseous flows in micro-channels with CHF (constant heat flux) whose value is negative. The combined effect of viscous dissipation and compressibility is also investigated. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The computations are performed for channels with constant heat flux with range from −104 to −102 Wm−2. The channel height ranges from 10 to 100 μm and the aspect ratio of the channel height and length is 200. The stagnation pressure varies from 120 to 500 kPa. The outlet pressure is fixed at the atmosphere. The wall and bulk temperatures in micro-channels are compared with those of the case of positive heat flux and also compared with those of the incompressible flow in a conventional sized channel. In the case of negative heat flux, temperature profiles normalized by heat flux have different trends in the case of positive heat flux, when flow is fast. A gas temperature falls down due to the energy conversion. A correlation for the prediction of the wall temperature of the gaseous flow in the micro-channel is proposed.


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