Computational Study of Flow and Heat Transfer in Matrix Cooling Channels

2014 ◽  
Author(s):  
Sivasankara Reddy Ramireddy ◽  
Siddappa Pallavagere Gurusiddappa ◽  
V. Kesavan ◽  
S. Kishore Kumar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Computational Study ◽  
Side Wall ◽  
Transfer Enhancement ◽  
Cooling Channels ◽  
Aspect Ratios ◽  
The Matrix

A Numerical study of fluid flow, heat transfer and pressure drop in a stationary matrix cooling channel having an angle of 45 degrees for the three Reynolds numbers (24000<Re<60000) and four sub-channel aspect ratios (0.5<W/H<1.2) have been performed. This includes different shaped sub-channels such as Rectangular, U, and then two, three layered matrix combined with open and closed matrix channels. The simulation shows the development of vortices along the channel. The flow turning and impingement after hitting the side wall have significant contribution to the heat transfer enhancement. The Nusselt number and friction factor have been evaluated and compared with limited experimental results. The highest heat transfer enhancement is found at impingement region as the flow takes turn and impinges on to the wall. But slight enhancement in heat transfer is observed at turning region. The sub-channel aspect ratio has less impact on heat transfer enhancement, but more effect on pressure drop. The performance of closed matrix is relatively better than the open matrix one. The overall thermal performance (η) of the matrix having U sub-channel is nearly 10% higher than the rectangular sub-channel.

Numerical Investigation of Secondary Flow Vortex Core Structure in the Two-Pass Rectangular Channel With 45° Ribs

2015 ◽  
Author(s):  
Jiangnan Zhu ◽  
Tieyu Gao ◽  
Jun Li ◽  
Guojun Li ◽  
Jianying Gong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Secondary Flow ◽  
Gas Turbine ◽  
Vortex Core ◽  
Side Wall ◽  
Main Flow ◽  
Transfer Enhancement ◽  
Cooling Channels ◽  
Flow Vortex

The secondary flow which is generated by the angled rib is one of the key factors of heat transfer enhancement in gas turbine blade cooling channels. However, the current studies are all based on the velocity vector and streamline, which limit the research on the detailed micro-structure of secondary flow. In order to make further targeted optimization on the flow and heat transfer in the cooling channels of gas turbine blade, it is necessary to firstly investigate the generation, interaction, dissipation and the influence on heat transfer of secondary flow with the help of new topological method. This paper reports the numerical study of the secondary flow and the effect of secondary flow on heat transfer enhancement in rectangular two-pass channel with 45° ribs. Based on the vortex core technology, the structure of secondary flow can be clearly shown and studied. The results showed that the main flow secondary flow is thrown to the outer side wall after the corner due to the centrifugal force. Then it is weakened in the second pass and a new main flow secondary flow is generated at the same time near the opposite side wall in the second pass. The Nusselt number distribution has also been compared with the secondary flow vortex core distribution. The results shows that the heat transfer strength is weakened in the second pass due to the interaction between the old main flow secondary flow and the new one. These two secondary flows are in opposite rotation direction, which reduces the disturbance and mass transfer strength in the channel.

scholarly journals 460 A Numerical Study on Heat Transfer Enhancement and Pressure drop Decrease of Heat Exchanger by Setting Inserted Plates in Duct

2005 ◽  
Vol 2005.15 (0) ◽  
pp. 541-544
Author(s):  
Himsar AMBARITA ◽  
Kouki KISHINAMI ◽  
Kazuhiko SATO ◽  
Masasi DAIMARUYA ◽  
Hiromu SUGIYAMA ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Transfer Enhancement

Thermal-Hydraulic Performance Enhancement by the Combination of Rectangular Winglet Pair and V-Shaped Dimples

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Inderjot Kaur ◽  
Prashant Singh ◽  
Srinath V. Ekkad
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Hydraulic Performance ◽  
Channel Height ◽  
Transfer Enhancement ◽  
Spacing Variation ◽  
Lower Heat

Abstract This paper presents numerical study on heat transfer enhancement due to the combination of rectangular winglet pair with V-dimples in an array-type arrangement. Array of rectangular winglet pairs results in heat transfer enhancement, however, at a cost of significant pressure drop, resulting in reduced thermal-hydraulic performance (THP). On the other hand, dimples are associated with lower heat transfer enhancement levels at relatively lower pumping power penalty. To this end, a combination of rectangular winglet pair and V-shaped dimples has been studied in this paper, where the arrangements were intended to achieve enhanced thermal-hydraulic performance. Three different configurations, namely, rectangular winglet pair, rectangular winglet pair with one V-dimple between two consecutive winglets, and rectangular winglet pair with two V-dimples packed in a pitch, are studied here. The variation of heat transfer enhancement, pressure drop gain, and THP with respect to winglet-to-winglet (S) spacing variation for rectangular winglet pair and rectangular winglet pair with one V-dimple configuration is presented at a Reynolds number of 25,000. The THP of the rectangular winglet pair configuration decreases up to S/H equal to 2.5 and then increases (H: channel height). For rectangular winglet pair with one V-dimple, three values of winglet-to-dimple (P) spacings are analyzed. For fixed S/H, the highest P/H configuration provided highest heat transfer enhancement and THP. Among the three configurations studied, rectangular winglet pair with two V-dimples resulted in the highest thermal-hydraulic performance.

Numerical Study of Forced Convection in a Partially Porous Channel With Discrete Heat Sources

1995 ◽  
Vol 117 (1) ◽  
pp. 46-51 ◽  
Author(s):  
H. A. Hadim ◽  
A. Bethancourt
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Pressure Drop ◽  
Heat Source ◽  
Heat Transfer Enhancement ◽  
Forced Convection ◽  
Numerical Study ◽  
Heat Sources ◽  
Transfer Enhancement ◽  
Discrete Heat Sources

A numerical study was performed to analyze steady laminar forced convection in a channel partially filled with a fluid-saturated porous medium and containing discrete heat sources on the bottom wall. Hydrodynamic and heat transfer results are reported for the configuration in which the porous layers are located above the heat sources while the rest of the channel is nonporous. The flow in the porous medium was modeled using the Brinkman-Forchheimer extended Darcy model. Parametric studies were conducted to evaluate the effects of variable heat source spacing and heat source width on heat transfer enhancement and pressure drop in the channel. The results indicate that when the heat source spacing was increased within the range considered, there was a negligible change in heat transfer enhancement while the pressure drop decreased significantly. When the heat source width was decreased, there was a moderate increase in heat transfer enhancement and a significant decrease in pressure drop.

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