scholarly journals Numerical Study of Heat Transfer Enhancement of Turbulent Flow Using Twisted Tape Insert Fitted with Hemispherical Extruded Surface

2020 ◽  
Vol 38 (2) ◽  
pp. 314-320
Author(s):  
Fazlay Rubbi ◽  
Khairul Habib ◽  
Mehedi Tusar ◽  
Likhan Das ◽  
Md. Tauhidur Rahman
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Twisted Tape ◽  
Transfer Enhancement

Numerical study on heat transfer enhancement using twisted tape with trapezoidal ribs in an internal flow

2020 ◽  
Author(s):  
Mohammed Zaki Hayat ◽  
Gopal Nandan ◽  
Arun Kumar Tiwari ◽  
Sanjeev Kumar Sharma ◽  
Ramakant Shrivastava ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Internal Flow ◽  
Twisted Tape ◽  
Transfer Enhancement

Numerical Prediction of Turbulent Flow and Heat Transfer Enhancement in a Square Passage With Various Truncated Ribs on One Wall

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Gongnan Xie ◽  
Jian Liu ◽  
Weihong Zhang ◽  
Giulio Lorenzini ◽  
Cesare Biserni
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
Heat Transfer Enhancement ◽  
Pressure Loss ◽  
Numerical Study ◽  
Skew Angle ◽  
Transfer Enhancement ◽  
Reduced Pressure ◽  
Flow And Heat Transfer

Repeated ribs are often employed in the midsection of internal cooling passages of turbine blades to augment the heat transfer by air flowing through the internal ribbed passages. Though the research of flow structure and augmented heat transfer inside various ribbed passages has been well conducted, previous works mostly paid much attention to the influence of rib topology (height-to-pitch, blockage ratio, skew angle, rib shape). The possible problem involved in the usage of ribs (especially with larger blockage ratios) is pressure loss penalty. Thus, in this case, the design of truncated ribs whose length is less than the passage width might fit the specific cooling requirements when pressure loss is critically considered. A numerical study of truncated ribs on turbulent flow and heat transfer inside a passage of a gas turbine blade is performed when the inlet Reynolds number ranges from 8000 to 24,000. Different truncation ratio (truncated-length to passage-width) rib geometries are designed and then the effect of truncation ratio on the pressure drop and heat transfer enhancement is observed under the condition of constant total length. The overall performance characteristics of various truncated rib passages are also compared. It is found that the heated face with a rib that is truncated 12% in length in the center (case A) has the highest heat transfer coefficient, while the heated face with a rib that is truncated 4% at three locations over its length, in the center and two sides (case D), has a reduced pressure loss compared with passages of other designs and provides the lowest friction factors. Although case A shows larger heat transfer augmentation, case D can be promisingly used to augment side-wall heat transfer when the pressure loss is considered and the Reynolds number is relatively large.

scholarly journals Two-way fluid-structure interaction study of twisted tape insert in a circular tube having integral fins with nanofluid

2021 ◽  
Vol 3 (8(111)) ◽  
pp. 25-34
Author(s):  
Mustafa Abdulsalam Mustafa ◽  
Atheer Raheem Abdullah ◽  
Wajeeh Kamal Hasan ◽  
Laith J. Habeeb ◽  
Maadh Fawzi Nassar
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Heat Transfer Enhancement ◽  
Circular Tube ◽  
Fluid Structure Interaction ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Laminar And Turbulent Flow

This work deals with fluid-structure interaction (FSI), one of the emerging areas of numerical simulation and calculation. This research shows a numerical study investigating heat transfer enhancement and fluid-structure interaction in a circular finned tube by using alumina nanofluid as a working fluid with a typical twisted tape that has a twisting ratio of 1.85. The studied nanofluid volumes of fraction are φ=0, 3, 5 % under conditions of laminar and turbulent flow. The solution for such problems is based on the relations of continuum mechanics and is mostly done with numerical methods. FSI occurs when the flow of fluid influences the properties of a structure or vice versa. It is a computational challenge to deal with such problems due to complexity in defining the geometries, nature of the interaction between a fluid and solid, intricate physics of fluids and requirements of computational resources. CFD investigations were made based on the numerical finite volume techniques to solve the governing three-dimensional partial differential equations to get the influence of inserted twisted tape and concentration of nanofluid on heat transfer enhancement, friction loss, average Nusselt number, velocity profile, thermal performance factor characteristics, and two-way interaction in a circular tube at laminar and turbulent flow. The governing continuity, momentum and energy transfer equations are solved using Ansys Fluent and Transient Structural. The simulation results show that the deformations of two-way coupling fluctuate from side to side, with 0.004 mm, as maximum amplitude, located at the typical twisted tape center. Heat transfer dissipation improved by adding fins and as Reynolds numbers increase the heat transfer behavior increases.

Numerical study of heat transfer enhancement using perforated dual twisted tape inserts in converging-diverging tubes

2018 ◽  
Vol 47 (5) ◽  
pp. 754-767 ◽  
Author(s):  
Farhad Afsharpanah ◽  
Khashayar Pakzad ◽  
Mehrshad Amirsoleymani ◽  
Mojtaba Aghajani Delavar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Twisted Tape ◽  
Transfer Enhancement

Experimental and Numerical Study of Heat Transfer and Turbulent Flow Characteristics in Three-Short-Pass Serpentine Cooling Channels With Miniature W-Ribs

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Yu Rao ◽  
Zhongqiu Guo ◽  
Deqiang Wang
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Heat Transfer Enhancement ◽  
Pressure Loss ◽  
Numerical Study ◽  
Total Heat ◽  
Transfer Enhancement ◽  
Total Heat Transfer ◽  
Serpentine Channel

Abstract Detailed experimental and numerical studies have been conducted on the heat transfer, pressure loss, and turbulent flow structure of a three-short-pass serpentine cooling channel with miniature W-shaped ribs on the wall under the Reynolds numbers from 8500 to 60,000. Steady-state heat transfer experiments were done to obtain the globally averaged and total heat transfer performance of each ribbed pass of the serpentine channel, and the streamwise pressure loss characteristics of the serpentine-channel flow were also obtained by multipoint pressure measurements. Additionally, the transient liquid crystal thermography technique was also used to obtain the local heat transfer distributions on the miniature W-ribbed surface of each pass. Furthermore, numerical simulations were done by using the AKN k–ε turbulence model to reveal the detailed turbulent flow and heat transfer characteristics in the serpentine channel. The experiments indicate that the miniature W-ribbed short pass has significantly enhanced total heat transfer by a factor of up to 4.0. The total heat transfer enhancement shows appreciably different values in different passes of the serpentine channel, and the second pass shows about 15% higher heat transfer enhancement than the first pass, and the third pass shows the highest heat transfer enhancement, which is about 15% higher than the second pass. The pressure loss measurements indicate that the two flow turnings contribute more than 90% of the total pressure loss in the serpentine channel with one ribbed pass with the miniature W ribs. The numerical simulations indicate that the flow turnings significantly increase the turbulent mixing in the flow of the downstream pass, and the miniature W-ribs on the wall appreciably improve the near-wall vortex mixing, which contributes the heat transfer enhancement.

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