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 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.

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.

scholarly journals Preparation of Hollow Silica by Spray Drying of Nano Silica Particles and Its Heat Transfer Property

2012 ◽  
Vol 22 (10) ◽  
pp. 531-538 ◽  
Author(s):  
Chan Ki Youn ◽  
Hyung Mi Lim ◽  
Sujin Cha ◽  
Dae Sung Kim ◽  
Seung-Ho Lee
Keyword(s):  
Heat Transfer ◽  
Spray Drying ◽  
Silica Particles ◽  
Nano Silica ◽  
Transfer Property ◽  
Hollow Silica ◽  
Heat Transfer Property

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.

scholarly journals Analyzing the Heat Transfer Property of Heat Pipe Influenced by Integrated Cooling Apparatus

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Chen-Ching Ting ◽  
Chien-Chih Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Pipe ◽  
Cooling Water ◽  
Cooling Power ◽  
Capillary Structure ◽  
Transfer Property ◽  
Face To Face ◽  
Heat Transfer Property ◽  
Circulating Cooling Water

Heat pipe with discrete heat transfer property is often called thermal superconductor because it has extremely large thermal conductivity. This special heat transfer property is destroyed by integrating cooling apparatus and further reducing the cooling power of a heat pipe cooler. This paper experimentally studied the heat transfer property of heat pipe influenced by integrated cooling apparatus. To simplify the investigating process, a home-made square heat pipe with the dimensions of L×W×H=10×10×100 mm3 was built with two pieces of copper plates and two pieces of glass plates face to face, respectively. The two pieces of copper plates were constructed with inside walls of capillary structure and the two pieces of glasses were with antifog inside walls for observing the inner phenomenon. Moreover, isothermal circulating cooling water was applied outside the heat pipe instead of cooling fin. The results show that heat vapor in the heat pipe is condensed earlier and cannot reach the remote section of condenser. In other words, the heat transfer property of heat pipe is destroyed by integrating cooling water. This phenomenon causes the unfavorable cooling power of the heat pipe cooler.

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.

Modified Algebraical Cebeci --- Smith Turbulent Viscosity Model for the Entire Surface of a Blunted Cone

2020 ◽  
pp. 28-41
Author(s):  
V.V. Gorskiy ◽  
A.G. Loktionova
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Experimental Studies ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Entire Surface ◽  
Wide Range ◽  
Semi Empirical ◽  
Transfer Properties ◽  
Turbulent Pulsations

In order to compute the intensity of laminar-turbulent heat transfer, algebraic or differential models are commonly used, which are designed to compute the contribution of turbulent pulsations to the transfer properties of the gas. This, in turn, dictates the necessity of validating these semi-empirical models against experimental data obtained under conditions simulating the gas dynamics inherent to the phenomenon as observed in practice. The gas dynamic patterns observed during gradient flow around fragments of aircraft structure (such as a sphere or a cylinder) differs qualitatively from the patterns revealed by the flow around the lateral surfaces of these fragments, which necessitates using various semi-empirical approaches in this case, followed by mandatory validation against the results of respective experimental studies. In recent years, there appeared scientific publications dealing with modifying one of the algebraic models designed to compute the contribution of turbulent pulsations in the boundary layer to the transfer properties of the gas; this was accomplished by making use of experimental data obtained for a hemisphere at extremely high Reynolds numbers. The paper proposes a similar modification of the same turbulence model, based on fitting a wide range of experimental data obtained for lateral surfaces of spherically blunted cones. As a result of the investigations conducted, we stated a method for computing laminar-to-turbulent heat transfer over the entire surface of a blunted cone; the accuracy of the method is acceptable in terms of most practical applications. We show that the computational method presented is characterised by minimum error as compared to the most widely spread methods for solving this problem

Measurement and prediction of the heat transfer properties of hydrocarbon mixtures with potential application as aluminum cold rolling base oils

2015 ◽  
Vol 67 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Daniel Pattemore ◽  
David F. Heenan ◽  
Krzysztof R. Januszkiewicz
Keyword(s):  
Heat Transfer ◽  
Cold Rolling ◽  
Hydrodynamic Lubrication ◽  
Hydrocarbon Mixtures ◽  
Content Type ◽  
Base Oils ◽  
Hydrocarbon Solvents ◽  
Wide Range ◽  
Transfer Properties ◽  
Thermal Conductivities

Purpose – The objective of this paper is to measure the differences in heat transfer properties of refined hydrocarbon distillate fractions that are commonly used as base oils in aluminium sheet cold rolling applications and assess if the heat transfer coefficient (HTC) values for these oils can be predicted from their compositions. The composition and physical properties of these fluids affect their tribological behaviour by influencing hydrodynamic lubrication, wear debris removal and cooling. Design/methodology/approach – A purpose-built test rig was used to measure HTCs for a wide range of hydrocarbon solvents used as aluminium cold rolling oils. The results are expressed in the form of the HTCs relative to those of 14- to 16-carbon-chain-length normal paraffins. Measured HTC values were compared to values calculated from oil compositions and from the thermal conductivities of compounds representing different classes of typical oil components. Findings – There were significant differences between the heat transfer properties of various hydrocarbon solvents, and these differences could be estimated from their content of normal and simple iso-paraffins and heavily branched and cyclic hydrocarbons. The HTC of hydrocarbon mixtures increases with the increasing content of n-paraffinic compounds. Originality/value – This paper shows how one can estimate the relative HTCs of oils of known compositions, based on the relative thermal conductivities of model compounds. This is relevant to prediction of cooling properties of aluminium cold rolling base oils.

Simulation Study on Heat Insulating Material Used in Refrigerated Cargo Hold Shipboard of Fishing Vessel

2011 ◽  
Vol 311-313 ◽  
pp. 1953-1956
Author(s):  
Jing Fu Jia ◽  
Wei He
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Transfer Process ◽  
Transfer Model ◽  
Fishing Vessel ◽  
Transfer Property ◽  
Insulating Material ◽  
Temperature Distributions ◽  
Heat Transfer Property ◽  
Computational Fluid Dynamics Cfd

To choose the suitable heat insulating material for refrigerated cargo hold shipboard of fishing vessel, a steady state three-dimensional mathematical model of heat transfer is developed in this paper. The heat-transfer model is simplified reasonably in order to facilitate analyzing and solving. After defining the boundary conditions of the model according to the heat-transfer process of the shipboard, numerical simulations with different heat insulating material are performed using computational fluid dynamics (CFD) software PHOENICS. The obtained temperature distributions of the model in each case are analyzed. The suitable one is pointed out according to the degree of influence of the heat insulating material on heat-transfer property of the shipboard.

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