Numerical Study of Heat Transfer Enhancement Using Al2O3–Graphene/Water Hybrid Nanofluid Flow in Mini Tubes

2019 ◽  
Vol 43 (4) ◽  
pp. 1989-2000 ◽  
Author(s):  
Ahmed A. Hussien ◽  
Nadiahnor Md Yusop ◽  
Moh’d A. Al-Nimr ◽  
Mohd Z. Abdullah ◽  
Ayub Ahmed Janvekar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Hybrid Nanofluid ◽  
Transfer Enhancement ◽  
Nanofluid Flow

scholarly journals Numerical Study of Heat Transfer Enhancement for Mono and Hybrid Nanofluids Flow in a Straight Pipe

CFD letters ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 49-61
Author(s):  
Azraf Azman ◽  
Mohd Zamri Yusoff ◽  
Azfarizal Mukhtar ◽  
Prem Gunnasegaran ◽  
Nasri A. Hamid ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
Numerical Study ◽  
Reynold Number ◽  
Inlet Temperature ◽  
Hybrid Nanofluid ◽  
Transfer Enhancement ◽  
Straight Pipe ◽  
Hybrid Nanofluids

In recent years, there has been an increasing interest in heat transfer enhancement using nanofluids in channels due to current devices become smaller and more compact and are expected to perform better. Thus, we attempt to introduce hybrid nanofluids flow in a straight pipe using Ansys Fluent software. The simulation was prepared with certain specific parameters such as the hydraulic diameter is set at 10mm, the flow is a continuum, the Reynold number in the range of 5000 to 30000, k-e turbulent model used in this simulation, the inlet temperature 297 K, and the uniform temperature along the pipe at 313 K. This study was carried out on Al2O3+Cu / water hybrid nanofluids to analyse the thermal improvement and friction factor of nanofluids occur in a straight pipe. Then, the numerical results obtained were compared between mono and hybrid nanofluids. It was found that the mono nanofluids at 1% and 4% indicate a significant increase in Nusselt number at 17% and 24% respectively and hybrid nanofluid increase at 2% to 5.6% compared to base fluid. Whereas the friction factor remains similar for all the nanofluids. However, the performance evaluation criterion (PEC) has shown that hybrid nanofluids remain lower than mono nanofluids.

An Experimental and Numerical Study of Heat Transfer and Pressure Loss in a Rectangular Channel With V-Shaped Ribs

2006 ◽  
Author(s):  
Michael Maurer ◽  
Jens von Wolfersdorf ◽  
Michael Gritsch
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Pressure Loss ◽  
Numerical Study ◽  
Rectangular Channel ◽  
Reynolds Numbers ◽  
Transfer Enhancement ◽  
High Reynolds Numbers ◽  
High Reynolds

An experimental and numerical study was conducted to determine the thermal performance of V-shaped ribs in a rectangular channel with an aspect ratio of 2:1. Local heat transfer coefficients were measured using the steady state thermochromic liquid crystal technique. Periodic pressure losses were obtained with pressure taps along the smooth channel sidewall. Reynolds numbers from 95,000 to 500,000 were investigated with V-shaped ribs located on one side or on both sides of the test channel. The rib height-to-hydraulic diameter ratios (e/Dh) were 0.0625 and 0.02, and the rib pitch-to-height ratio (P/e) was 10. In addition, all test cases were investigated numerically. The commercial software FLUENT™ was used with a two-layer k-ε turbulence model. Numerically and experimentally obtained data were compared. It was determined that the heat transfer enhancement based on the heat transfer of a smooth wall levels off for Reynolds numbers over 200,000. The introduction of a second ribbed sidewall slightly increased the heat transfer enhancement whereas the pressure penalty was approximately doubled. Diminishing the rib height at high Reynolds numbers had the disadvantage of a slightly decreased heat transfer enhancement, but benefits in a significantly reduced pressure loss. At high Reynolds numbers small-scale ribs in a one-sided ribbed channel were shown to have the best thermal performance.

Sign in / Sign up

Export Citation Format

Share Document