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.

Performance Evaluation of Thermal Attributes in Impinging Jet Heat Sink using Airfoil Pillars with and without Nano Fluid

2021 ◽  
Vol 7 (5) ◽  
pp. 2808-2820
Author(s):  
Deepak Kumar ◽  
Mohammad Zunaid ◽  
Samsher Gautam
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Exchange Coefficient ◽  
Dimensional Model ◽  
Heat Exchange Coefficient ◽  
Three Dimensional Model ◽  
Nano Fluid ◽  
Nano Fluids

Objectives: In the current research three techniques have been operated to enhance the rate of heat transfer in a heat sink. The amalgamation of Impingement of jet, airfoil pillars and Nano fluids are used. Nano fluids has a lot of potential to enhance the heat transportation in contrast to the water. The investigation has been executed with the help of three dimensional numerical model using Computational fluid Dynamics. At the onset the model has been validated with the inspection carried out already in experimental form. The observations in the form of thermal attributes are investigated. From the results the conclusion is made that the use of airfoil pillars and Nano fluids has increased the thermal characteristics of the three dimensional model in the form of heat exchange coefficient by almost 28.2%. The Nano fluid has been utilized for the 0.5% concentration.

Conjugate Heat Transfer in a Hexagonal Micro Channel Using Hybrid Nano Fluids

2016 ◽  
Author(s):  
Shreyas S. Hegde ◽  
Narendran Ganesan ◽  
N. Gnanasekaran
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Conjugate Heat Transfer ◽  
Nano Particles ◽  
Micro Channel ◽  
Nano Fluid ◽  
Nano Fluids ◽  
Effect Of Surface

Research is being focused on the use of micro channels with nano fluids as the heat sinks. This requires fundamental understanding of the heat transfer phenomenon in micro channels. The objective of this paper is to present results from a numerical study on laminar forced convection in a Hexagonal Micro Channel (HMC) heat sink. In particular, the numerical study is carried out using a single phase model. The fluid considered is Alumina-Copper hybrid Nano fluid. The performance of Al2O3+Cu+water is compared with Al2O3+water nano fluid and pure water with different volume fractions. The solid region of the channel is assumed as aluminum with a hydraulic diameter of 175μm. The solid and fluid regions of the micro channel are discretized using finite volume method by combining Navier Stokes equation and energy equation for conjugate heat transfer. The thermo physical properties for alumina nanoparticles are calculated by considering it as a spherical particle of 45nm diameter. The effect of surface roughness on convective heat transfer coefficient and pressure drop for the case of nano fluids is also considered. The analysis is further extended by adding pulsating input and by varying the velocity sinusoidally. The Brownian motion of nano particles is increased to study the efficiency of the heat sink. This ensures all the nano particles are in suspension and the randomness increases the micro convection in the fluid. Incorporating the pulsating flow increases the dispersion of the heat in the nano fluid at a faster rate and also decreases particle settlement in laminar flow. The combined effect of surface roughness and pulsating flow accounts for the change in the velocity profile and thermal boundary layer of the channel. Also the effect of surface roughness ranging from 0.2–0.6 is attempted and the variations in pressure drop, Nusselt number, and heat transfer coefficient are studied. The influence of hexagonal geometry and its interaction with alumina nano fluids is intensively studied by evaluating a three dimensional conjugate heat transfer model. The effect of side wall angle of 45°, 50° and 55° are computed to relate the velocity function with pressure drop, surface roughness and local heat transfer coefficient. The variation of Nusselt number with very low volume fraction of nano particles with a minimal amount of pressure drop is also presented.

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 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.

scholarly journals Characterization of AL2O3 Nano Particles in Engine Oil for Enhancing the Heat transfer rate

2018 ◽  
Vol 7 (2.32) ◽  
pp. 237
Author(s):  
Ch Sridhar Yesaswi ◽  
K Ajay Krishna ◽  
A Pavan Gopal Varma ◽  
K Girish ◽  
K Jagadeesh Varma
Keyword(s):  
Heat Transfer ◽  
Structural Characteristics ◽  
Thermal Characteristics ◽  
Internal Heat ◽  
Vital Role ◽  
Nano Particles ◽  
Engine Oil ◽  
Al2o3 Nanoparticles ◽  
Engine Oils ◽  
Nano Fluids

Selection of suitable engine oils becoming more challenging for automobile engineers. Life of the engine majorly depends upon engine oil, type of fuel being used and various other thermal and structural characteristics of the engine. Dissipation of heat is one of the major consideration in the design of automobile engines. Generally engine oils are used for the lubrication between piston and cylinder but to enhance the cooling effectiveness Nano-particles are added in the lubricant, so that internal heat generation in the engines can be minimized. Nano-fluids are playing a vital role in heat transfer applications because of its enhanced thermal conductivity nature and generally these fluids are colloidal mixture of Nano particles and base fluids. Intense research studies over Nano fluids are very high because of their sublime behavior.Recently. Advanced research over Nano technology has gone to a situation where two or more Nano particles are made to mix in a base fluids and generally we call this as hybrid Nano fluids. In this work, preparation of Al2O3 nanoparticles and mixing them with 10W30 engine oil were carried out. By various techniques thermal characteristics of fluid are identified with different parameters.  

scholarly journals Use of Nano Fluids in Nuclear Technology: A Review

2021 ◽  
Vol 64 (2) ◽  
pp. 149-160
Author(s):  
Tahir Iqbal ◽  
Maria Zafar ◽  
Mohsin Ijaz
Keyword(s):  
Heat Transfer ◽  
Nuclear Reactors ◽  
Industrial Applications ◽  
Nano Particles ◽  
Transfer Property ◽  
Nano Fluid ◽  
Heat Transfer Property ◽  
Wide Range ◽  
Transfer Properties ◽  
Nano Fluids

Nuclear energy is the most important source to produce electricity. The production processes are very important for reducing risks and increasing the efficiency. Nano-fluids also have the potential to transfer heat with improved thermo-physical properties which can be applicable in many devices for better performance. Advancement in nanotechnology develops new fluids which transfer heat called nano-fluids. So, for heat exchange in the core of nuclear reactors, nano-fluids are used because of their unique heat transfer properties. For significant improvement in properties, the modest concentration of nano-particles is required. Recent research is more about behaviour of nano-fluids to utilize their unique properties. Heat transfer property is very important for industrial applications, nuclear reactors, transportation, and electronics and also in biomedicine. Nano-fluid acts like smart fluid, where heat transfer property can be controlled. This review establishes a focus on the wide range of recent and future uses about nano-fluids, related to their improved properties of heat transfer that may be controllable and other specific properties of nano- fluids.    

scholarly journals Experimental study of heat transfer through cooling water circuit in a reactor vault by using Al2O3 nano fluid

2018 ◽  
Vol 22 (2) ◽  
pp. 1149-1161 ◽  
Author(s):  
Maria Anish ◽  
Balakrishnan Kanimozh
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Base Fluid ◽  
Nuclear Reactor ◽  
Characteristic Curve ◽  
Reactor Core ◽  
Cooling Water ◽  
Heat Transfer Process ◽  
Nano Fluid ◽  
Al2o3 Nanoparticle

The heat produced in the nuclear reactor due to fission reaction must be kept in control or else it will damage the components in the reactor core. Nuclear plants are using water for the operation dissipation of heat. Instead, some chemical substances which have higher heat transfer coefficient and high thermal conductivity. This experiment aims to find out how efficiently a nanofluid can dissipate heat from the reactor vault. The most commonly used nanofluid is Al2O3 nanoparticle with water or ethylene as base fluid. The Al2O3 has good thermal property and it is easily available. In addition, it can be stabilized in various PH levels. The nanofluid is fed into the reactor?s coolant circuit. The various temperature distribution leads to different characteristic curve that occurs on various valve condition leading to a detailed study on how temperature distribution carries throughout the cooling circuit. As a combination of Al2O3 as a nanoparticle and therminol 55 as base fluid are used for the heat transfer process. The Al2O3 nanoparticle is mixed in therminol 55 at 0.05 vol.% concentration. Numerical analysis on the reactor vault model was carried out by using ABAQUS and the experimental results were compared with numerical results.

Evaluation of Nusselt number and pressure drop in hexagonal and rectangular micro-channels in the presence of nano-fluids

2020 ◽  
Vol 234 (6) ◽  
pp. 665-672
Author(s):  
S Emami ◽  
MH Dibaei Bonab ◽  
M Mohammadiun ◽  
H Mohammadiun ◽  
M Sadi
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Heat Sinks ◽  
Nano Particles ◽  
Geometrical Parameters ◽  
Micro Channels ◽  
Nano Fluids

Few papers investigated the effect of different nano-fluids and geometrical parameters of the micro channels on the performance of heat sinks. In this study, Nusselt number and pressure drop are investigated in differential geometry and Reynolds numbers. Then the effect of the micro-channel is studied for different heat flux. The results show that hexagonal micro-channels represents a better performance than the rectangular and the heat transfer of without using nano-particles in the hexagonal cross-section is about 9% higher than the rectangular cross-section and with the presence of nanoparticles (Al2O3 - CUO- TiO2, φ  =  4%), heat transfer is about 30 to 40% higher than the base liquid.

Heat Transfer Effect of CNT and Ethylene Glycol Based Nano-Fluid in Twisted Tape Heat Exchanger with Balls

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
R. Saravanan ◽  
M. Karuppasamy ◽  
M. Chandrasekaran ◽  
V. Muthuraman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Heat Exchangers ◽  
Twisted Tape ◽  
Heat Transfer Fluids ◽  
Nano Fluid ◽  
Carbon Nano Tubes ◽  
Heat Transfer Improvement ◽  
Nano Fluids

Heat transfer improvement is the main parameter in a heat exchanging equipment. Few methods to increase the coefficient of heat transfer is by creating the turbulence in heat exchanging elements and changing the heat transfer fluids. For current analysis of tube heat exchangers, tape inserts containing balls are implemented with nano-fluids in Carbon Nano Tubes (CNT) and ethylene glycol. 3D modelling and simulation of twisted tape heat exchanger with balls were carried out using Solidworks and ANSYS Workbench. Heat transfer rate, friction factor, temperature difference in the heat exchangers, Reynolds number and Nusselt number variations are assessed in this work.

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