scholarly journals Experimental Study on Flow and Heat Transfer Characteristics in the Circular-Arc-Shaped Flow Channel

2021 ◽  
Vol 12 (1) ◽  
pp. 376
Author(s):  
Hui Song ◽  
Shuangxiu Fan ◽  
Dayi Qu
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Cross Section ◽  
Convective Heat ◽  
Heat Transfer Performance ◽  
Flow Channel ◽  
Transfer Performance ◽  
Flow Process ◽  
Circular Arc ◽  
Flow Channels

Different parameters of the circular-arc, trapezoidal and equal cross-section-shaped flow channels were analyzed, and the core volume goodness factor was used for the comparison of the three different types of flow channels. During the experiment, the Reynolds number (Re) on the air side ranged from 1200 to 5100. The results showed that the overall heat transfer performance of the three channels in this paper are circular-arc, trapezoidal and equal cross-section in order from good to bad. The overall heat transfer enhancement performance of the circular-arc flow channel is the best, which is 9–26.2% and 3.6–11.8% higher than that of the equal and trapezoidal cross-section flow channels, respectively. This showed that although the divergent flow channel structure reduces the fluid velocity in the flow process, it weakens the convective heat transfer performance in the flow channel. However, this gradually decreasing cross-sectional area improves the downstream heat transfer area and reduces the pressure drop in the flow process, thus promoting the overall heat transfer performance. With the increase in the circular radius (R), both the j and f factors increase, and the highest overall heat transfer performance is obtained at R = 300 mm. The convective heat transfer coefficient increases with the decrease in the inlet height.

scholarly journals Convective heat transfer performance of thermal oil-based nanofluids in a high-temperature thermohydraulic loop

2022 ◽  
Vol 171 ◽  
pp. 107243
Author(s):  
Javier Gil-Font ◽  
Nuria Navarrete ◽  
Estefanía Cervantes ◽  
Rosa Mondragón ◽  
Salvador F. Torró ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Thermal Oil

Convective Heat Transfer Performance of FC-72 in a Pin-Finned Channel

2008 ◽  
Author(s):  
Liang-Han Chien ◽  
S.-Y. Pei ◽  
T.-Y. Wu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Flow Rate ◽  
Smooth Surface ◽  
Heat Transfer Performance ◽  
Fluid Temperature ◽  
Transfer Performance ◽  
Finned Surface

This study investigates the influence of the heat flux and mass velocity on convective heat transfer performance of FC-72 in a rectangular channel of 20mm in width and 2 mm in height. The heated side has either a smooth surface or a pin-finned surface. The inlet fluid temperature is maintained at 30°C. The total length of the test channel is 113 mm, with a heated length of 25mm. The flow rate varies between 80 and 960 ml/min, and the heat flux sets between 18 and 50 W/cm2. The experimental results show that the controlling variable is heat flux instead of flow rate because of the boiling activities in FC-72. At a fixed flow rate, the pin-finned surface yields up to 20% higher heat transfer coefficient and greater critical heat flux than those of a smooth surface.

Preliminary Investigation on Convective Heat Transfer of Rod Bundle Flow With Spacer Grid for Nuclear Fuel Assembly Application

2015 ◽  
Author(s):  
Chi Young Lee ◽  
Chang Hwan Shin ◽  
Wang Kee In ◽  
Dong Seok Oh ◽  
Tae Hyun Chun
Keyword(s):  
Heat Transfer ◽  
Fuel Assembly ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Transfer Performance ◽  
Axial Flow ◽  
Transfer Performance ◽  
Spacer Grid ◽  
Rod Bundle ◽  
Nuclear Fuel Assembly

The convective heat transfer of rod bundle flow with spacer grid was investigated preliminarily for nuclear reactor core application. As the test fluid, the water was used. To simulate the nuclear fuel assembly, 4×4 rod bundle with P/D (=pitch between rods/rod diameter) of ∼1.35 was prepared together with a spacer grid with twist-mixing vane. A single heated section with five thermocouples embedded in the surface along the circumferential direction was installed around the center subchannel. The measurements of wall temperatures were carried out upstream and downstream of spacer grid. For the rod bundle flow at the inlet of spacer grid (i.e., upstream of spacer grid), the wall temperatures at the gap and subchannel centers exhibited the higher and lower, respectively, which was because in the subchannel center, the axial flow velocity became higher, as compared with the gap center. On the other hand, downstream of spacer grid, the rod wall toward the tip of twist-mixing vane showed the lowest temperature in the measurements along the circumferential direction of rod wall. Near the twist-mixing vane, the averaged wall temperature was observed to be remarkably low, which implies that the twist-mixing vane is an effective tool to enhance the convective heat transfer performance. However, along the axial flow direction behind the spacer grid, the averaged wall temperatures became to increase, and the enhancement of convective heat transfer performance by mixing vane faded away.

Paper 5: A Comparison of the Natural Convective Heat Transfer Performance of Three Fluids from a Horizontal Flat Surface near the Critical Point

1967 ◽  
Vol 182 (9) ◽  
pp. 27-35
Author(s):  
J. W. Bramall ◽  
T. C. Daniels
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Critical Region ◽  
Heat Transfer Performance ◽  
Heating Surface ◽  
Transfer Performance ◽  
Surface Geometry ◽  
Lack Of Information ◽  
Show Evidence

One of the main problems with heat transfer research in the critical region is the lack of accurate thermodynamic and transport property data. This lack of information makes the actual heat transfer performance very difficult to correlate, whilst the extreme property variations produce other effects, which are also dependent on the heating surface geometry. Three fluids, carbon dioxide, nitrous oxide, and chlorotrifluoromethane, were therefore tested with a view to establishing whether they had similar regions of heat transfer and whether any similarity with boiling existed. The results show that in the critical region the normal convective heat transfer is augmented by a process to give results which look very like the lower portion of the normal boiling curve. Finally the authors show evidence to support the theory that there are preferential areas of heat transfer in the supercritical region.

An X-lattice cored rectangular honeycomb with enhanced convective heat transfer performance

2020 ◽  
Vol 166 ◽  
pp. 114687 ◽  
Author(s):  
Hongbin Yan ◽  
Qiancheng Zhang ◽  
Weijian Chen ◽  
Gongnan Xie ◽  
Jianjun Dang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Transfer Performance ◽  
Transfer Performance
Sign in / Sign up

Export Citation Format

Share Document