Numerical Investigation of Fluid Flow and Heat Transfer in Finned Micro-Channels with Nanofluids

2015 ◽  
Vol 813-814 ◽  
pp. 723-728
Author(s):  
Deepak Kumar ◽  
D.P. Mishra
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Wall Temperature ◽  
Transfer Rate ◽  
Base Fluid ◽  
Thermal Characteristics ◽  
Mixed Flow ◽  
Nano Fluid ◽  
Flow And Heat Transfer ◽  
Micro Channels

Conservation equations of mass, momentum and energy have been solved using Fluent 14 to compute the Nusselt number and wall temperature of a finned rectangular Micro-channel for a laminar flow for water and nanofluids under mixed flow condition. Alumina based water is considered as nano fluid for the present investigation. It has been found from the numerical investigation that as the percentage of alumina is increased in the base fluid (water) the heat transfer rate is increased. It has been found that the wall temperature decreases with increase in fin number. The heat transfer is found to be more in rectangular shaped fin compared to any other shape both for the water and nanofluid. In addition to thermal characteristics, the variation of pressure drop for different fin number has also been investigated.

Viscous Dissipation Effect on Heat Transfer Through Nano Fluid in a Vertical Wavy Channel with Travelling Thermal Wave

2020 ◽  
Vol 28 ◽  
pp. 17-31
Author(s):  
Paladugu Venkata Ramana ◽  
Gosukonda Srinivas ◽  
G.V.P.N Srikanth
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Fluid Flow ◽  
Differential Equations ◽  
Viscous Dissipation ◽  
Thermal Wave ◽  
Transfer Rate ◽  
Wavy Channel ◽  
Nano Fluid ◽  
Flow And Heat Transfer

The effect of viscous dissipation on heat transfer through nano-fluid in a vertical wavy channel filled with porous media has been studied. The consequential differential equations are simplified by the R-K method of 6th order. The numerical obtained results are shown in the graphs. The significant results of fluid flow and heat transfer rate and its properties are shown graphically. Nusslet values are calculated a for varying the governing parameters φ Da, Gr, ε, Ec and the remaining parameters are to be constants.

Two-Phase Study of Fluid Flow and Heat Transfer in Gas-Solid Flows (Nanofluids)

2011 ◽  
Vol 110-116 ◽  
pp. 3878-3882 ◽  
Author(s):  
Hossein Afshar ◽  
Mehrzad Shams ◽  
Seyed Mojtba Mousavi Nainian ◽  
Goodarz Ahmadi
Keyword(s):  
Heat Transfer ◽  
Transfer Rate ◽  
Base Fluid ◽  
Volume Fraction ◽  
Maxwell Model ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Gravity Forces ◽  
Phase Study ◽  
Two Phase Heat Transfer

In this paper, two phase heat transfer of a mixture of nanopaticles in air flow as a type of nanofluid is studied. Volume fraction of the dispersed phase is very low (less than 1%). Nanoparticles travel in the base fluid due to drag, brownian and gravity forces and are tracked according to lagrangian approach. Effect of reduced specific heat of nanofluid on heat transfer is considered. The results show an increase in heat transfer rate which is very much more than that predicted by the Maxwell model.

scholarly journals Numerical Calculations on Flow and Heat Transfer in Smooth and Ribbed Two-Pass Square Channels under Rotational Effects

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongyang Shen ◽  
Yonghui Xie ◽  
Di Zhang ◽  
Gongnan Xie
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Transfer Rate ◽  
Heat Transfer Performance ◽  
Thermal Characteristics ◽  
Transfer Performance ◽  
Operation Condition ◽  
Flow And Heat Transfer ◽  
Rotation Numbers ◽  
First Pass

U-shaped channel, which is also called two-pass channel, commonly exists in gas turbine internal coolant passages. Ribbed walls are frequently adopted in internal passage to enhance the heat transfer. Considering the rotational condition of gas turbine blade on operation, the effect of rotation is also investigated for the coolant channel which is close to real operation condition. Thus, the objective of this study is to discuss the effect of rotation on fluid flow and heat transfer performance of U-shaped channel with ribbed walls under high rotational numbers. Investigated Reynolds number is Re=12500and the rotation numbers areRob=0.4and 0.6. In the results, the spatially heat transfer coefficient distributions are exhibited to discuss the effect of rotation and roughened walls. It is found that ribbed walls enhance the heat transfer rate significantly. Under the rotational condition, theNuin the first pass with outward flow is increased while that in the second pass is decreased. Finally, averageNuratio, friction ratio, and thermal performance are all presented to discuss the thermal characteristics.

scholarly journals Performance Improvement of Base Fluid Heat Transfer Medium Using Nano Fluid Particles

2020 ◽  
Vol 23 (4) ◽  
pp. 235-243
Author(s):  
T. Sathish
Keyword(s):  
Heat Transfer ◽  
Performance Improvement ◽  
Base Fluid ◽  
Flow Problem ◽  
Thermal Characteristics ◽  
Nano Particles ◽  
Simulation Tool ◽  
Heat Transfer Medium ◽  
Nano Fluid ◽  
Nano Fluids

Base fluids like water, ethylene glycolandengineoilare conventionally used as a heat transfer medium. The performance of heat transferred is improved in the conventional fluids with the addition of Nano particles. Hence, this paper considers the forced conventional flow problem over the base fluid within a uniform heated tube placed on a wall. The analysis of heattransferco-efficientis done through a constant Reynoldsnumberfor both Nano and base fluid with a simulation tool. Further, a comparative analysis is carried out with heat transfer coefficient over the base and various Nano fluids. It is seen that the Nano fluids has a better performance due to its better thermal characteristics under standard conditions.

scholarly journals Numerical Investigation on Forced Hybrid Nanofluid Flow and Heat Transfer Inside a Three-Dimensional Annulus Equipped with Hot and Cold Rods: Using Symmetry Simulation

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1873
Author(s):  
Aysan Shahsavar Goldanlou ◽  
Mohammad Badri ◽  
Behzad Heidarshenas ◽  
Ahmed Kadhim Hussein ◽  
Sara Rostami ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Base Fluid ◽  
Thermal Characteristics ◽  
Reynolds Numbers ◽  
The Other ◽  
Heat Transfer Fluid ◽  
Hybrid Nanofluid ◽  
Cu Nanoparticles ◽  
Flow And Heat Transfer

A 3D computational fluid dynamics method is used in the current study to investigate the hybrid nanofluid (HNF) flow and heat transfer in an annulus with hot and cold rods. The chief goal of the current study is to examine the influences of dissimilar Reynolds numbers, emissivity coefficients, and dissimilar volume fractions of nanoparticles on hydraulic and thermal characteristics of the studied annulus. In this way, the geometry is modeled using a symmetry scheme. The heat transfer fluid is a water, ethylene–glycol, or water/ethylene–glycol mixture-based Cu-Al2O3 HNF, which is a Newtonian NF. According to the findings for the model at Re = 3000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. ϕ1 and ϕ2 are the volume concentration of Al2O3 and Cu nanoparticles, respectively. For all studied cases, the total average Nusselt number (Nuave) reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 or 0.02 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. Additionally, for the case with water as the base fluid, the total Nuave at ϕ2 = 0.05 is higher than the values at ϕ2 = 0.00. On the other hand, for the other cases, the total Nuave at ϕ2 = 0.05 is lower than the values at ϕ2 = 0.00. For all studied cases, the case with water as the base fluid has the maximum Nuave. Plus, for the model at Re = 4000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. For all studied cases, the total Nuave reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. The Nuave augments are found by an increment of Reynolds numbers. Higher emissivity values should lead to higher radiation heat transfer, but the portion of radiative heat transfer in the studied annulus is low and therefore, has no observable increment in HNF flow and heat transfer.

Numerical Heat Transfer and Pressure Drop Studies of Turbulent Al2O3 - Ethylene Glycol/Water Nanofluid Flow in an Automotive Radiator Tube

2015 ◽  
Vol 787 ◽  
pp. 152-156 ◽  
Author(s):  
N. Mohanrajhu ◽  
K. Purushothaman ◽  
N. Kulasekharan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Ethylene Glycol ◽  
Base Fluid ◽  
Unit Length ◽  
Thermal Characteristics ◽  
Turbulent Regime ◽  
Pumping Power ◽  
Numerical Heat Transfer ◽  
Nano Fluid

Automotive radiators use flattened tubes within which Ethylene Glycol (EG) and Water (W) based nanofluids flow to enhance the heat transfer. Computations were carried out to understand the flow and thermal characteristics of the Aluminium oxide based nanofluids, with EG:W ratio of 60:40 as the base fluid, flowing inside a flattened tube. The flow was maintained in the turbulent regime with the Reynolds number (Re) ranging from 5,000 to 14,000.Investigations were carried out for nano particle concentrations (φ) varying from 1% to 5% of the base fluid by volume. Computations were also carried out for a circular tube to study the influence of tube shape. The nanofluid with φ = 5% increased the Nusselt number values by 40% for the flattened tubes compared to the base fluid at Re =14,000. These estimates are done at constant flow Reynolds number in-line with literature, which necessitated increased inlet velocity, which meant increased pumping power. Pumping power increased with increase in φ and Re. For a constant pumping power per unit length (Pp) of 5W/m the values of average heat transfer coefficient () decreases with increase in φ. The values of for the 2% and 5% nano fluid were lower than the base fluid by 6% and 23.8% respectively. Nanofluid with φ = 1% alone showed a 1.2% higher value than the base fluid indicating the need of further exploration of φ in a closer range.

Numerical Investigation of Flow and Heat Transfer around Two Semi-Circular Cylinders with a Splitter Plate

2011 ◽  
Vol 42 (7) ◽  
pp. 595-612
Author(s):  
Masome Heidary ◽  
Mousa Farhadi ◽  
Kurosh Sedighi ◽  
Mostafa Nourollahi
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Splitter Plate ◽  
Circular Cylinders ◽  
Flow And Heat Transfer
Sign in / Sign up

Export Citation Format

Share Document