1) The presentation discusses the effect of initial surface condition on pool boiling of nanofluids. Recent research has found that nanofluid heat transfer performance is greatly affected by nanoparticles depositing on the heated surface during boiling.
2) The current research uses new precision machining techniques to create consistent surface textures and surfactants to enhance nanofluid stability and prevent nanoparticle deposition. Experimental results show that surfactant addition eliminates deposition and improves heat transfer.
3) Heat transfer is also influenced by surface roughness, with rougher surfaces enhancing boiling. However, when nanoparticle size is larger than surface roughness features, deposition does not occur and heat transfer is improved with or without surfactant addition. The research aims
EFFECT OF (AL2 O3) NANOFLUID ON HEAT TRANSFER CHARACTERISTICS FOR CIRCULAR FI...IAEME Publication
In the present work Experimental investigation of heat transfer enhancement in double tube heat exchanger and circular finned double tube heat exchanger. Experimental work included to design heat exchanger and manufacture eight circular fins made of copper of (66mm) outer diameter, (22mm) inner diameter, (1mm) thickness and (111.11mm) distance between fins.
EFFECT OF (AL2 O3) NANOFLUID ON HEAT TRANSFER CHARACTERISTICS FOR CIRCULAR FI...IAEME Publication
In the present work Experimental investigation of heat transfer enhancement in double tube heat exchanger and circular finned double tube heat exchanger. Experimental work included to design heat exchanger and manufacture eight circular fins made of copper of (66mm) outer diameter, (22mm) inner diameter, (1mm) thickness and (111.11mm) distance between fins.
The main objective of this project is to achieve the highest possible thermal properties at the smallest possible concentration.
we compare conventional and Nanofluid coolant and find out which has better thermal properties so that it can be used in lathe, turbines, and nuclear reactor.
Nanofluids are now developing technology in main purpose heat transfer stream. In paper has brief information on the introduction and preparation methods of nanofluids. This paper prepared from the study of online resources
NATURAL CONVECTIVE HEAT TRANSFER BY Al2O3 &PbO NANOFLUIDSAlagappapandian M
In this presentation related about natural convective heat transfer incresed by using different nano particles. in this fluid is called nanofluids. Nanofluids improve the heat transfer rate of base fluid.
Enhancement of rate of heat transfer using nano fluidsSharathKumar528
Nano fluids as coolants and lubricants is still very primitive in technology. This presentation explores the future of nano fluids for enhanced heat transfer.
Study of Heat Transfer Characteristics of Nanofluid as Coolant on a Single Cylinder Diesel Engine with Spiral Radiator.
Team Members: Sandeep Raj Kanth, Viral Hitenkumar Naik, Rudra Ranjan Swain
Guide: Dr. G. Naga Srinivasulu, Assistant Professor, Mechanical Engineering Department, NIT Warangal
It's a presentation prepared from a paper named "Latest developments on the viscosity of nanofluids." The original paper is an open-source content in ELSEVIER.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
ENHANCEMENT OF HEAT TRANSFER IN SHELL AND TUBE EXCHANGER USING NANO FLUIDS Vineeth Sundar
Nano fluid is a new engineering fluid which could improve the performance of heat exchanger.
The aim of this paper is to study the effect of different particle shapes (cylindrical, bricks, blades, and platelets) on the overall heat transfer coefficient, heat transfer rate and entropy generation of shell and tube heat exchanger with different baffle angles and segmental baffle.
The main objective of this project is to achieve the highest possible thermal properties at the smallest possible concentration.
we compare conventional and Nanofluid coolant and find out which has better thermal properties so that it can be used in lathe, turbines, and nuclear reactor.
Nanofluids are now developing technology in main purpose heat transfer stream. In paper has brief information on the introduction and preparation methods of nanofluids. This paper prepared from the study of online resources
NATURAL CONVECTIVE HEAT TRANSFER BY Al2O3 &PbO NANOFLUIDSAlagappapandian M
In this presentation related about natural convective heat transfer incresed by using different nano particles. in this fluid is called nanofluids. Nanofluids improve the heat transfer rate of base fluid.
Enhancement of rate of heat transfer using nano fluidsSharathKumar528
Nano fluids as coolants and lubricants is still very primitive in technology. This presentation explores the future of nano fluids for enhanced heat transfer.
Study of Heat Transfer Characteristics of Nanofluid as Coolant on a Single Cylinder Diesel Engine with Spiral Radiator.
Team Members: Sandeep Raj Kanth, Viral Hitenkumar Naik, Rudra Ranjan Swain
Guide: Dr. G. Naga Srinivasulu, Assistant Professor, Mechanical Engineering Department, NIT Warangal
It's a presentation prepared from a paper named "Latest developments on the viscosity of nanofluids." The original paper is an open-source content in ELSEVIER.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
ENHANCEMENT OF HEAT TRANSFER IN SHELL AND TUBE EXCHANGER USING NANO FLUIDS Vineeth Sundar
Nano fluid is a new engineering fluid which could improve the performance of heat exchanger.
The aim of this paper is to study the effect of different particle shapes (cylindrical, bricks, blades, and platelets) on the overall heat transfer coefficient, heat transfer rate and entropy generation of shell and tube heat exchanger with different baffle angles and segmental baffle.
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...IAEME Publication
In the present work, the enhancement of natural convection heat transfer utilizing nano fluids as working fluid from horizontal circular cylinder situated in a square enclosure is investigated numerically. Different types of nano particles were tested. The types of the nano fluids are Cu, Al2O3 and TiO3 with water as base fluid. A model is developed to analyze heat transfer performance of nano fluids inside an enclosure taking into account the solid particle dispersionrs on the flow and heat
transfer characteristics.
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...IAEME Publication
In the present work, the enhancement of natural convection heat transfer utilizing nanofluids as working fluid from horizontal circular cylinder situated in a square enclosure is investigated numerically. The type of the nanofluid is the water-based copper Cu. A model is developed to analyze heat transfer performance of nanofluids inside an enclosure taking into account the solid particle dispersionrs on the flow and heat transfer characteristics. The study uses different Raylieh
numbers (104 , 105 , and 106 ), different enclosure width to cylinder diameter ratios W/D (1.667, 2.5 and 5) and volume fraction of nanoparticles between 0 to 0.2. The work included the solution of the governing equations in the vorticity-stream function formulation which were transformed into body fitted coordinate system
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
Porous media has two specifications: First its dissipation area is greater than the conventional fins that enhance heat convection. Second the irregular motion of the fluid flow around the individual beads mixes the fluid more effectively. Nanofluids are mixtures of base fluid with a very small amount of nanoparticles having dimensions from 1 to 100 nm, with very high thermal conductivities, so it would be the best convection heat transfer by using porous media and nanofluids. Thus studies need to be conducted involving nanofluids in porous media. For that, the purpose of this article is to summarize the published subjects respect to the enhancement of convective heat transfer using porous media and nanofluids and identifies opportunities for future research.
This technique works by generating ions or electrically
charged atoms using electrodes placed close to one
another on a computer chip. Generated ions are passed
from electrode to electrode, with collisions between ions
and neutral air atoms propelling the air forward in what is
called the corona wind effect – the process that cools.
Analysis on thermal performance of Co3O4 Nanofluid in heat exchangerHrishikesh725754
Final year mechanical engineering project presentation. Findings obtained through simulations, using ANSYS. Modelling done using SolidWorks. Tabulated results and graphical representation of results portraying comparison to performance of Al2O3 nanofluid in same model.
Effect Of Cuo-Distilled Water Based Nanofluids On Heat Transfer Characteristi...IJERA Editor
In this paper, the heat transfer and pressure drop characteristics of the distilled water and the copper oxide-distilled water based nanofluid flowing in a horizontal circular pipe under constant heat flux condition are studied. Copper oxide nanoparticles of 40nm size are dispersed in distilled water using sodium dodecyl sulphate as surfactant and sonicated the nanofluid for three hour. Both surfactant and sonication increases the stability of the nanofluid. The nanofluids are made in three different concentration i.e. 0.1 Vol. %, 0.25 Vol. % and 0.50 Vol. %. The thermal conductivity is measured by KD2 PRO, density with pycnometer, viscosity with Brookfield LVDV-III rheometer. The results show that the thermal conductivity increases with both temperature and concentration. The viscosity and density increases with concentration but decreases with temperature. The specific heat is calculated by model and it decreases with concentration. The experimental local Nusselt number of distilled water is compared with local Nusselt number obtained by the well known shah equation for laminar flow under constant heat flux condition for validation of the experimental set up. The relative error is 4.48 % for the Reynolds number 750.9. The heat transfer coefficient increases with increase in both flow rate and concentration. It increases from 14.33 % to 46.1 % when the concentration is increased from 0.1 Vol. % to 0.5 Vol. % at 20 LPH flow rate. Friction factor decreases with increase in flow rate. It decreases 66.54 % when the flow rate increases from 10 LPH to 30 LPH for 0.1 Vol. %.
automotive vehicles will have radiator for the rejection of the heat . for effective rejection of the heat we can use nano fluids . nano fluids need some preparations before we use them in the radiators. by using nanofluids we can increase the heat rejection for very high speed engines.
Improving the Cooling Performance of Automobile Radiator with TiO2/Water Nano...ijsrd.com
In this paper, forced convective heat transfer in a water based nanofluid has experimentally beencompared to that of pure water in an automobile radiator. Five different concentrations of nanofluids inthe range of 0.1-1 vol.% have been prepared by the addition of TiO2 nanoparticles into the water. The test liquid flows through the radiator consisted of 34 vertical tubes with elliptical cross section and airmakes a cross flow inside the tube bank with constant speed. Liquid flow rate has been changed in therange of 90-120 l/min to have the fully turbulent regime. Results demonstrate that increasing the fluid circulating rate canimprove the heat transfer performance. Meanwhile, application of nanofluid with low concentrations can enhance heat transfer efficiency up to 45% in comparison with pure water.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Sarah aull secondary electron yield of srf materialsthinfilmsworkshop
In the quest of new materials for SRF applications, the secondary electron yield (SEY) needs also to be taken into consideration. A high SEY holds the risk that multipacting becomes again a main performance limitation of an SRF cavity. In the worst case, a too high SEY makes a material completely unsuitablefor an RF exposed surface. This talk will discuss general aspects of the role of the surface condition and present SEY measurements on different SRF relevant materials, i.e. MgB2, Nb3Sn and NbTiN.
Sarah aull surface resistance of a bulk-like nb filmthinfilmsworkshop
CERNs quadrupole resonator allows surface resistance measurements throughout a broad parameter range. Besides measuring the surface resistance as function of RF field and temperature for different frequencies, it is also possible to vary the cooling rate and apply additional magnetic fields. This talk will present RF results on a bulk-like Nb film with special focus on the cooling conditions.
Sarah aull surface resistance of a bulk-like nb film
Semianr Presentation
1. Presented by: Mohamed Hamda
M.A.Sc Candidate
Supervisor: Dr. M. Hamed
On The Effect of Initial Surface
Condition on Pool Boiling of
Nanofluids
2. Outline
• Pool Boiling.
• Nanofluids.
• Literature review.
• Recent Research in TPL.
• Current research.
• Conclusion.
• Future work.
• Publications.
2
3. Why Pool Boiling?
• Free Convection - Water: 20 - 100 (W/(m2K))
• Forced Convection - Water: 50 - 10.000
(W/(m2K))
• Boiling Water : 3.000 - 100.000 (W/(m2K))
Boiling Heat transfer coefficients are the highest
among different heat convection mechanisms.
6
4. Pool Boiling Curve
7
* Heat and Mass Transfer: Fundamentals & Applications,Fourth Edition, Yunus A. Cengel
5. Thermal conductivity of different
materials
Liquids Metals
k - W/(m.K)
Steel, Carbon 1% 43
Aluminium 205
Copper 401
k - W/(m.K)
Alcohol 0.17
Engine Oil 0.15
Water 0.58
8
• The thermal conductivity of liquids is three orders of
magnitude less than of metals.
• The idea is to increase the thermal conductivity of liquids.
6. How can we do that?
• Powder of metal has particles of certain size
(10 ~ 100 nm) dispersed into liquid.
• This mixture is now called Nanofluid or
Nanoparticles suspension.
9
7. Is Nanofluid a novel idea?
• Maxwell model (1881)
– Effective thermal conductivity increases with the
volume fraction of the solid particles as well as the
ratio of the surface area to volume of the particle.
– Confined to millimeter-sized particles.
– Not practical (severe clogging problems).
• Lee, Choi and et al. (1999)
– Reported 20% increase in the thermal conductivity of
CuO nanoparticles (10 nm) suspended in ethylene
glycol.
10
8. Literature Review
11
* O. Ahmed, M.S. Hamed, Experimental investigation of the effect of particle
deposition on pool boiling of nanofluids
9. Recent Research in TPL
12
Researcher
(Year)
Experiment
Type
Ra (nm)
Concentration
%
Nanofluid
Material
Particle
size
pH Remarks
Osama
Ahmed
(2011)
Pool Boiling
100 ~
150
50
0.01
0.1
0.5
Al2O3
40 ~ 50
nm
5 and
6.5
Enhancement
&
deterioration
Ahmed
Abd El-
hady
(2013)
Pool and Jet
Impingement
Boiling
20, 80
and 420
0.005
0.01
Al2O3
CuO
10 nm
50 nm
6.5
Enhancement
&
deterioration
10. Findings from Literature Review
13
• Contradicting results!
• Heat transfer deterioration is always noticed with
nanoparticles deposition on heated surface.
• Most enhancement results were reported for
heated wires.
• Deterioration is more likely to happen with flat or
horizontal heated surfaces.
• Heater geometry affects Nano fluid heat transfer.
11. What is new in this research?
Old technique
• Polishing by emery paper.
• Inconsistent surface texture.
New technique
• High precision machining.
• Consistent surface texture.
14
1. Surface Preparation
12. What is new in this research?
2. Using surfactants to enhance the stability of
nanofluids.
• Surfactant is a compound that lowers the surface
tension.
• Sodium dodecylbenzenesulfonate (SDBS).
15
13. Nanofluid Preparation
• Deionized water.
• Al2O3 , Particle size =40 nm ,(0.05%wt)
• Sodium dodecylbenzenesulfonate “SDBS”
(0.1%wt).
19
1. Li et al, Evaluation on dispersion behavior of the aqueous copper nano-
suspensions.
2. Wang et al, Influence of pH and SDBS on the Stability and Thermal
Conductivity of Nanofluids.
17. Boiling curves on Ra=60 nm
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 2 4 6 8 10 12 14
q”MW/m2
ΔT
Water Before
NF,SDBS(0.1%)
NF,SDBS(1.0%)
Water After
25
18. Boiling curves on Ra=60 nm
• Heat transfer enhancement in natural convection
regime and deterioration in nucleate boiling
regime.
• Nanoparticles deposition has been noticed.
• ONB has been delayed using Nanofluids.
• Increasing SDBS concentration has effectively
eliminated deposition and thus heat transfer
enhancement is achieved.
• No deposition was confirmed by boiling pure
water on the same surface from the Nanofluid
experiment.
26
20. Boiling curves on R=6 nm
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 2 4 6 8 10 12 14 16 18 20
q”MW/m2
ΔT
Water Before
NF,SDBS(0.1%)
NF,SDBS(0.0%)
Water After
28
21. Boiling curves on R=6 nm
• Heat transfer is affected by the surface
roughness.
• SDBS accelerates Onset of Nucleate
Boiling(ONB).
• Heat transfer enhancement is achieved with
and without adding SDBS.
• No deposition is noticed.
• Nanoparticle size is larger than surface
roughness.
30
25. Conclusions
• Modern manufacturing technologies
introduced new types of fluids.
• Nanofluid heat transfer is greatly affected by
initial surface conditions.
• Surfactants enhance stability of Nanofluids.
• Heat transfer deterioration results from
Nanoparticles deposition.
34
26. Future Work
• Develop a matrix to quantify the contribution
of each component used in Nanofluid
preparation.
• Test the performance of Nanofluid on very
rough surface.
• Understanding the Nanofluid interactions with
active nucleation sites using engineered Nano-
indentation.
35
27. Publication
• N.A. Almalki, M. Hamda, M. S. Hamed, On The Effect
of Initial Surface Condition on Pool Boiling of
Nanofluids,9th International Conference on Boiling
and Condensation Heat Transfer, April 26-30, 2015 –
Boulder, Colorado. (Extended Abstract Accepted)
36