PERFORMANCE ANALYSIS OF AUTOMOBILE RADIATOR A Project work Submitted in partial fulfillment of the requirements for the award of the degree of
Bachelor of Technology In Mechanical Engineering Submitted by
PAVAN KUMAR. N (Regd.No.14FE1A0384 ) VINAY KUMAR. M (Regd.No.14FE1A0373)
LEELA MANEENDRA. M (Regd.No.14FE1A0365) ANAND BABU. K (Regd.No.14FE1A0362 )
Under the guidance of
Mr. K.SIVA KRISHNA M. Tech Assistant Professor
Department of Mechanical Engineering
VIGNAN’S LARA INSTITUTE OF TECHNOLOGY & SCIENCE (Approved by AICTE, New Delhi, Affiliated to JNTU, Kakinada)
VADLAMUDI, GUNTUR, A.P, INDIA. 2017
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CERTIFICATE
This is to certify that the project entitled “ PERFORMANCE ANALYSIS OF AUTOMOBILE RADIATOR “ is a bonafied work done by Pavan Kumar.
N(14FE1A0384),Leela Maneendra. M(14FE1A0365), Vinay Kumar. M(14FE1A0373), M(14FE1A0373), Anand Babu. K(14FE1A0362) under my supervision and submitted in partial fulfillment of the requirements for the award of the degree of bachelor of technology in Mechanical Engineering of this institution affiliated to Jawaharlal Nehru Technological University Kakinada, during the academic year 2017-18. The results embedded in this thesis have not been submitted to any other university/institute for the award of any degree/diploma.
Project Guide
Head of the Department
Mr. K.SIVA KRISHNA
Mr. P.BHASKARA RAO
M.Tech
M.Tech
2
DECLARATION
We here by declare that the work described in this project entitled “PERFORMANCE ANALYSIS OF AUTOMOBILE RADIATOR” Which is
submitted by
us in partial fulfillment for the award of Bachelor of Technology in the Department of Mechanical Engineering of Vignan’s Lara Institute of Technology And Sciences,
Vadlamudi, affiliated to Jawaharlal Nehru Technological University Kakinada, Andhra Pradesh, is the result of work done by us under the guidance of Mr. K.SIVA KRISHNA M.Tech. The work is original and has not been submitted for any Degree/Diploma of this or any other university.
Signature PAVAN KUMAR. N
(14FE1A0384)
LEELA MANEENDRA. M
(14FE1A0365)
VINAY KUMAR. M
(14FE1A0373)
ANAND BABU. K
(14FE1A0364)
Place: Vadlamudi Date: 3
ACKNOWLEDGEMENT It is our bonded duty to acknowledge our gratefulness to the people Who helped us directly or indirectly to do the project. We are thankful to our project guide Mr. K. SIVA KRISHNA M.Tech., Assistant professor of Mechanical Engineering for his valuable suggestion in successful completion of our project. We are deeply indebted to our Head Of Department Mr. P. BHASKARA RAO M.Tech., who moulded us both technically and morally for achieving greater
success in life. We are very grateful to our principal Dr. K. PHANEENDRA KUMAR , for providing us required infrastructural facilities and creating a good environment which leads to the competition of our project successfully Finally, we thank each and every one for their contribution in successful completion of this project.
PROJECT ASSOCIATES PAVAN KUMAR. N
(14FE1A0384)
LEELA MANEENDRA. M
(14FE1A0365)
VINAY KUMAR. M
(14FE1A0373)
ANAND KUMAR. K
(14FE1A0362)
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ABSTRACT The thermal performance of an automotive radiator plays an important role in the performance of an automobile’s cooling system and all other associated systems.
For a number of years, this component has suffered from the little attention with very little changing in its manufacturing cost, operation and geometry. As opposed to the old tubular heat exchangers currently form the backbone of today’s process
industry with their advanced performance reading levels tubular heat exchanges can only dream of. In this thesis, we perform first solid modeling of the Radiator in creo and then this solid model is transferred to the ANSYS Workbench mesh module for meshing. After completing meshing, this meshed model is transferred to ANSYS CFD for CFD Analysis. Once CFD Analysis is complied with ANSYS CFD. Our Aim is to examine how the efficiency of the radiator can be enhanced by changing certain geometrical and operating parameter like Fluid Composition (Additives), Composition percentage, Tube Diameter etc. After completing all the above parametric study, we can suggest best configured radiator for optimum performance.
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1. INTRODUCTION
There are two main types of cooling system for keeping the temperature of the automobile engine within the reasonable limits. These are the direct cooling or Air Cooling and the indirect Air or Water cooling systems. The indirect air cooling is called Water cooling system. In indirect cooling, as the coolant flows through the tubes of the radiator, heat is transferred through the Fins and tube walls to the air by conduction and convection.
1.1 RADIATOR A radiator is a type of heat exchanger. It is designed to transfer heat from the hot coolant that flows through it to the air blown through it by the fan. Most modern cars use aluminum radiators. These radiators are made by brazing thin aluminum fins to flattened aluminum tubes. The coolant flows from the inlet to the outlet through many tubes mounted in a parallel arrangement. The fins conduct the heat from the tubes and transfer it to the air flowing through the radiator. The tubes sometimes have a type of fin inserted into them called a turbulator, which increases the turbulence of the fluid flowing through the tubes. If the fluid flows very smoothly through the tubes, only the fluid actually touching the tubes would be cooled directly. The amount of heat transferred to the tubes from the fluid ru nning through them depends on the difference in temperature between the tube and the fluid touching it. So if the fluid that is in contact with the tube cools down quickly, less heat will be transferred. By creating turbulence inside the tube, all of the fluid mixes together, keeping the temperature of the fluid touching the tubes up so that more heat can be extracted, and all of the fluid inside the tube is used effectively. 6
1.2 PARTS OF THE RADIATOR
1.2.1 RADIATOR HOSES 1.2.2 PRESSURE CAP & RESERVE TANK 1.2.3 RADIATOR CORE 1.2.4 RADIATOR COOLING FAN 1.2.5 COOLING FINS 1.2.1 RADIATOR HOSES There are several rubber hoses that make up the plumbing to connect the components of of the cooling system. system. The main hoses are are called the upper and and lower radiator hoses. These two hoses are approximately approximately 2 inches in diameter and direct coolant between the engine
and
radiator. Two
the additional
hoses, called heater hoses, supply hot coolant from the engine core.
to
the
These
approximately diameter.
One
heater
hoses 1
are
inch of
in
these these
hoses may have a heater control valve mounted in-line to block the hot coolant from entering the heater core when the the air conditioner is set to max-cool. A fifth hose, called the bypass hose, is used to circulate the coolant through the engine, bypassing the radiator, when the thermostat is closed. closed. Some engines do not not use a rubber hose. Instead, they might use a metal metal tube or have a built-in passage in the front housing. 7
1.2.2 PRESSURE CAP & RESERVE TANK As coolant gets hot, it expands. expands. Since the cooling system system is sealed, this expansion causes an increase in pressure in the cooling system, which is normal and part of the design. design. When coolant is under pressure, pressure, the temperature temperature where the liquid begins to to boil is considerably considerably higher. This pressure, coupled coupled with the higher boiling point of ethylene glycol, allows the coolant to safely reach temperatures in excess of 250 degrees. The radiator pressure cap is a simple device that will maintain pressure in the cooling system up to a certain point. If the pressure builds up higher than the set pressure point, there is a spring loaded valve, calibrated to the correct Pounds per Square Inch (psi), to release the pressure. When the cooling system pressure reaches the point where the cap needs to release this excess pressure, a small amount of coolant is bled off. It could happen during stop and go traffic on an extremely hot day, or if the cooling system is malfunctioning. malfunctioning. If it does release release pressure under these conditions, there is a system in place to capture the released coolant and store it in a plastic tank tank that is usually not pressurized. pressurized. Since there is now less coolant in the system, as the engine cools down a partial vacuum is formed. The radiator cap on these closed closed systems has a secondary valve valve to allow the vacuum in the cooling system to draw the coolant back into the radiator from the reserve tank (like pulling pulling the plunger back on a hypodermic needle) needle) There are usually markings on the side of the plastic tank marked Full-Cold, and Full Hot. When the engine is at normal normal operating temperature, the the coolant in the 8
translucent reserve tank should be up to the Full-Hot line. After the engine has been sitting for several hours and is cold to the touch, the coolant should be at the Full-Cold line.
1.2.3 RADIATOR CORE The hot coolant is also used to provide heat to the interior of the vehicle when needed. This is a simple and straight forward forward system that includes a heater core, which looks like a small version of a radiator, connected to the cooling system with a pair of rubber hoses. One hose brings hot coolant from the water pump to the heater core and the other hose returns the coolant to the top of the engine. There is usually a heater control valve in one of of the hoses to block the flow of coolant into the heater core when maximum air conditioning is called for.
1.2.4 RADIATOR COOLING FAN Mounted on the back of the radiator on the side closest to the engine is one or two electric fans inside a housing that is designed to protect fingers and to direct the air flow. These fans are there to keep the air flow going through the radiator while the vehicle is going slow or is stopped with the engine running. If these fans stopped stopped working, every time you came to a stop, the engine temperature would begin rising. On older systems, systems, the fan was connected connected to the front of the water pump and would spin whenever the engine was running because it was driven by a fan 9
belt instead of an electric electric motor. In these cases, if a driver would would notice the engine begin to run hot in stop and go driving, the driver might put the car in neutral and rev the engine to turn the fan faster which which helped cool the engine. engine. Racing the engine on a car with a malfunctioning electric fan would only make things worse because you are producing more heat in the radiator with no fan to cool it off. The electric fans are controlled controlled by the vehicle's computer. computer. A temperature sensor monitors engine temperature temperature and sends sends this information information to the computer. computer. The computer determines if the fan should be turned on and actuates the fan relay if additional air flow through the radiator is necessary. If the car has air conditioning, there is an additional radiator mounted in front of the normal radiator. This "radiator" is called called the air conditioner conditioner condenser, which also needs to be cooled cooled by the air flow entering the engine compartment. compartment. You can find out more about the air conditioning condenser by going to our article on Automotive Air Conditioning. Conditioning. As long as the air conditioning conditioning is turned on, the system will keep keep the fan running, even if if the engine is not running hot. This is because if there is no air flow through the air conditioning condenser, the air conditioner will not be able to cool the air entering the interior
1.2.5 COOLING FINS A fin is a surface that extends from an object to increase the rate of heat transfer to or from the environment by increasing convection. The amount of conduction, convection, radiation of an object determines the amount of heat it transfers. Increasing the temperature difference between the object and the environment, increasing the convection heat transfer coefficient, or increasing the 10
surface area of the object increases the heat transfer. Sometimes it is not economical or it is not feasible to change the first two options. Adding a fin to the object, however, increases the surface area and can sometimes be economical solution to heat transfer problems. Circumferential fins around the cylinder of a motor cycle engine and fins attached to condenser tubes of a refrigerator are a few familiar examples.
1.3 WORKING OF RADIATOR
FIG 1.3 RADIATOR
The pump sends the fluid into the engine block, where it makes its way through passages in the engine around the cylinders. Then it returns through the cylinder head of the engine. The thermostat is located where the fluid leaves the engine. The plumbing around the thermostat sends the fluid back to the pump directly if the thermostat is closed. If it is open, the fluid goes through the radiator first and then back to the pump.
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There is also a separate circuit for the heating system. This circuit takes fluid from the cylinder head and passes it through a heater core and then back to the pump. On cars with automatic transmissions, there is normally also a separate circuit for cooling the transmission fluid built into the radiator. The oil from the transmission is pumped by the transmission through a second heat exchanger inside the radiator, as shown in fig.1.3
1.4 COOLING SYSTEM & ANTIFREEZE An automobile’s cooling system is the collection of parts and substances (coolants) that work together to maintain the engine’s temperature at optimal
levels. Comprising many different components such as water pump, coolant, a thermostat, etc, the system enables smooth and efficient functioning of the engine at the same time protecting it from damage. While it’s running, an automobile’s
engine generates enormous amounts of heat. Each combustion cycle entails thousands of controlled explosions taking place every minute inside the engine. If the automobile races on and the heat generated within isn’t dissipated, it would
cause the engine to self-destruct. Hence, it is imperative to concurrently remove the waste heat. While the waste heat is also dissipated through the intake of cool air and exit of hot exhaust gases, the engine’s cooling system is explicitly meant to
keep the temperature within limits. The cooling system essentially comprises passages inside the engine block and heads, a pump to circulate the coolant, a thermostat to control the flow of the coolant, a radiator to cool the coolant and a radiator cap controls the pressure within the system. In order to achieve the cooling action, the system circulates the liquid coolant.
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1.5 AUTOMOTIVE USE OF ANTIFREEZE The term engine coolant is widely used in the automotive industry, which covers its primary function of convective heat transfer. When used in an automotive context, corrosion inhibitors are also added to help protect vehicles ’ cooling systems, which often contain a range of electrochemically incompatible metals (aluminum, cast iron, copper, lead solder, etc). Antifreeze was developed to overcome the shortcomings of water as a heat transfer fluid. In most engines, freeze plugs are placed in the engine block which could protect the engine if no antifreeze was in the cooling system or if the ambient temperature dropped below the freezing point of the antifreeze. If the engine coolant gets too hot, it might boil while inside the engine, causing voids (pockets of steam) leading to the catastrophic failure of the engine. Using proper engine coolant and a pressurized coolant system can help alleviate both problems. Some antifreeze can prevent freezing till - 870C.
1.6 ANTIFREEZE AGENTS 1.6.1 METHANOL Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a chemical compound with chemical formula CH3OH (often abbreviated MeOH). It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). At room temperature it is a polar liquid and is used as an antifreeze, solvent, fuel, and as a denaturant for ethyl
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alcohol. It is not very popular for machinery, but it can be found in automotive windshield washer fluid, de-icers, and gasoline additives to name a few.
1.6.2 ETHYLENE GLYCOL Ethylene glycol (IUPAC name: ethane-1, 2-diol) is an organic compound widely used as an automotive antifreeze and a precursor to polymers. In its pure form, it is an odorless, colorless, syrupy, sweet tasting liquid. However, ethylene glycol is toxic, and ingestion can result in death. Ethylene glycol solutions became available in 1926 and were marketed as “permanent antifreeze,” since the higher boiling points provided advantages for
summertime use as well as during cold weather. They are still used today for a wide variety of applications, including automobiles. Being ubiquitous, ethylene glycol has been ingested on occasion, causing ethylene glycol poisoning. Coolant containing ethylene glycol should not be disposed of in a way that will result in it being ingested by animals, because of its toxicity. Many animals like its sweet taste. As little as a teaspoonful can be fatal to a cat, and four teaspoonfuls can be dangerous to a dog. In some places it is permitted to pour moderate amounts down the toilet, but there are also places where it can be taken for processing.
1.6.3 PROPYLENE GLYCOL Propylene glycol, on the other hand, is considerably less toxic and may be labeled as “nontoxic antifreeze”. It is used as antifreeze where ethylene
glycol would be inappropriate, such as in foodprocessing systems or in water pipes 14
in homes, as well as numerous other settings. It is also used in food, medicines, and cosmetics, often as a binding agent. Propylene glycol is fig. 4 is “generally recognized as safe” by the Food and Drug Administration (FDA) for use in food.
However, propylene glycol-based antifreeze should not be considered safe for consumption. In the event of accidental ingestion, emergency medical services should be contacted immediately.
1.7 FUNCTIONS OF ANTIFREEZE Engine antifreeze and additive mixture for automobile radiator are meant to
1.7.1 Reduce cooling system corrosion Every automotive cooling system will corrode eventually, but this mixture of antifreeze and additive will make the overall process of corrosion slow therefore, increasing the life of cooling system.
1.7.2 Reduce cavitation In large diesel engines, air or tiny bubbles in the coolant can cause serious problems or engine overheating. So, for a diesel vehicle, it is highly recommended that a cavitation reducing engine coolant must be used.
1.7.3 Buffer the acidity of your engine coolant The more acidic an engine coolant, the more quickly it can corrode and damage the cooling system and automobile radiator.
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1.7.4 Raise the boiling point of the engine coolant A higher boiling temperature means that the coolant can cool better as the engine gets hotter. It also reduces r educes the chance of blowing a head gasket.
1.8 MATERIALS Up to the 1980s, radiator cores were often made of copper (for fins) and brass (for tubes, headers, and side-plates, while tanks could also be made of brass of brass or
of plastic,, often of plastic
a polyamide polyamide)).
Starting
in
the
1970s,
use
of aluminium of aluminium increased, eventually taking over the vast majority of vehicular radiator applications. The main inducements for aluminium are reduced weight and cost. However, the superior cooling properties of Copper-Brass over Aluminium makes it preferential for high performance vehicles or stationary applications. In particular MW-class installations, copper-brass constructions are still dominant (See: Copper in heat exchangers ). CuproBraze is a copper-alloy heat exchangerttechnology for harsh temperature and pressure environments such as exchanger those
in
the
latest
generations
of
cleaner diesel
engines mandated
by environmental regulations. regulations .[3][4] Its performance advantages over radiators made with other materials include better thermal performance, heat transfer, size, strength,
durability,
emissions,
corrosion
antimicrobial benefits.
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resistance,
repairability,
and
1.8.1 ALUMINIUM PROPERITIES 1.8.1.1 Weight
One of the best known properties of aluminium is that it is light, with a density one third that of steel, 2,700 kg/m3. The low density of aluminium accounts for it being lightweight but this does not affect its strength.
1.8.1.2 Strength Aluminium alloys commonly have tensile strengths of between 70 and 700 MPa. The range for alloys used in extrusion is 150 – 300 MPa. Unlike most steel grades, aluminium does not become brittle at low temperatures. Instead, its strength increases. At high temperatures, aluminium’s strength decreases. At temperatures temperatures continuously above 100°C, strength is affected to the extent that the weakening must be taken into account.
1.8.1.3 Linear expansion Compared with other metals, aluminium has a relatively large coefficient of linear expansion. This has to be taken into account in some designs.
1.8.1.4 Machining: Aluminium is easily worked using most machining methods – milling, drilling, cutting, punching, bending, etc. Furthermore, the energy input
during machining is low.
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1.8.1.5 Formability Aluminium’s superior malleability is essential for extrusion. With the metal either
hot or cold, this property is also exploited in the rolling of strips and foils, as well as in bending and other forming operations.
1.8.1.6 Conductivity: Aluminium is an excellent conductor of heat and electricity. An aluminium conductor weighs approximately half as much as a copper conductor having the same conductivity.
1.8.1.7 Joining Features facilitating easy jointing are often incorporated into profile design. Fusion welding, Friction Stir Welding, bonding and taping are also used for joining. 1.8.1.8 Reflectivity
Another of the properties of aluminium is that it is a good reflector of both visible light and radiated heat. 1.8.1.9 Screening EMC
Tight aluminium boxes can effectively exclude or screen off electromagnetic radiation. The better the conductivity of a material, the better the shielding qualities.
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1.8.1.10 Corrosion resistance
Aluminium reacts with the oxygen in the air to form an extremely thin layer of oxide. Though it is only some hundredths of a (my)m thick (1 (my)m is one thousandth of a millimetre), this layer is dense and provides excellent corrosion protection. The layer is self-repairing if damaged. Anodising increases the thickness of the oxide layer and thus improves the strength of the natural corrosion protection. Where aluminium is used outdoors, thicknesses of between 15 and 25 ¥ìm (depending on wear and risk of corrosion) are common. Aluminium is extremely durable in neutral and slightly acid environments. In environments characterised by high acidity or high basicity, corrosion is rapid.
1.9 ASSUMPTIONS The results obtained are based on the t he following assumptions: a) Velocity and temperature at the entrance of the radiator core on both air and coolant sides are uniform. b) There are no phase changes (condensation or boiling) in all fluid streams. c) Fluid flow rate is uniformly distributed through the core in each pass on each fluid side. No stratification, flow bypassing, or flow leakages occur in any stream. The flow condition is characterized by the bulk speed at any cross section.
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d) The temperature of each fluid is uniform over every flow cross section, so that a single bulk temperature applies to each stream at a given cross section. e) The heat transfer coefficient between the fluid and tube material is uniform over the inner and outside tube surface for a constant fluid mass flow rate. f) For the extended fin of the radiator, the surface effectiveness is considered uniform and constant. g) Heat transfer area is distributed uniformly on each side h) Both the inner dimension and the outer dimension of the tube are assumed constant. i) The thermal conductivity of the tube material is constant in the axial direction. j) No internal source exists for thermal-energy generation. generation. k) There is no heat loss or gain external to the radiator and no axial heat conduction in the radiator. l) Thermal conduction parallel to the flow direction of both the wall and the fluids are equal to zero.
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2. LITERATURE Oliet et al. (2007) studied different factors which influence radiator
performance. It includes air, fin density, coolant flow and air inlet temperature. It is catch that heat transfer and performance of radiator strongly affected by air & coolant mass flow rate. As air and coolant flow increases cooling capacity also increases. When the air inlet temperature increases, the heat transfer and thus cooling quantity decreases. Smaller fin spacing and greater louver fin angle have higher heat transfer. Fin density may be increased till it blocks the air flow and heat transfer rate reduced. Sulaiman et al. (2009 ) use the computational Fluid Dynamics (CFD)
modeling simulation of air flow distribution from the automotive radiator fan to the radiator. The task undertook the model the geometries of the fan and its surroundings is the first step. The results show that the outlet air velocity is 10 m/s. The error of average outlet air velocity is 12.5 % due to difference in the tip shape of the blades. This study has shown that the CFD simulation is a useful tool in i n enhancing the design of the fan blade. In this paper this study has shown a simple solution to design a slightly aerodynamic shape of the fan hub. Chacko et al. (2005) used the concept that the efficiency of the vehicle
cooling system strongly rely on the air flow towards the radiator core. A 21
clear understanding of the flow pattern inside the radiator cover is required for optimizing the radiator cover shape to increase the flow toward the radiator core, thereby improving the thermal efficiency of the radiator. CFD analysis of the baseline design that was validated against test data showed that indispensable area of re-circulating flow to be inside the radiator cover. This recirculation reduced the flow towards the radiator core, leading to a reputation of hot air pockets close to the radiator surface and subsequent disgrace of radiator thermal efficiency. The CFD make able optimization led to radiator cover configuration that eliminated these recirculation area and increased the flow towards the radiator core by 34%. It is anticipated that this increase in radiator core flow would important to increase the radiator thermal efficiency. Jain et al. (2012) presented a computational fluid dynamics (CFD)
modeling of air flow to divide among several from a radiator axial flow fan used in an acid pump truck Tier4 Repower. CFD analysis was executed for an area weighted average static pressure is variance at the inlet and outlet of the fan. Pressure contours, path line and velocity vectors were plotted for detailing the flow characteristics for dissimilar orientations of the fan blade. This study showed how the flow of air was intermittent by the hub obstruction, thereby resulting in unwanted reverse flow regions. The different orientation of blades was also considered while operating CFD analysis. The study revealed that a left oriented blade fan with 22
counterclockwise rotation 5 performed the same as a right oriented blade fan with rotating the clockwise direction. The CFD results were in accord with the experimental data measured during physical testing. Singh et al. (2011) studied about the issues of geometric parameters of
a centrifugal fan with backward- and forward-curved blades has been inspected. Centrifugal fans are used for improving the heat dissipation from the internal combustion engine surfaces. The parameters studied in this study are number of blades, outlet angle and diameter ratio. In the range of parameters considered, forward curved blades have 4.5% lower efficiency with 21% higher mass flow fl ow rates and 42% higher power consumption compared to backward curved fan. Experimental investigations suggest that engine temperature drop is significant with forward curved blade fan with insignificant effect on mileage. Hence, use of forward fan is recommended on the vehicles where cooling requirements are high. The results suggest that fan with different blades would show same an action below high pressure coefficient. Increase in the number of blades increases the flow coefficient follow by increase in power coefficient due to better flow guidance and reduced losses. Kumawat et al. (2014) illustrated about the axial flow fans, while
incapable of increasing high pressures, they are well relevant for handling large volumes of air at comparatively low pressures. In general,
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they are low in cost, possess good efficiency and can have blades of airfoil shape. Axial flow fans show good efficiencies, and can to work at high static pressures if such operation is necessary. The presentation of an axial fan was simulated using CFD results were presented in the form of velocity vector and streamlines, which provided actual flow characteristics of air around the fan for different number of fan blades. The different parameters similar temperature, pressure, fan noise, turbulence and were also considered while performing CFD analysis. The study exposed that a fan with an optimum number of fan blades performed well as compared to the fan with less number of fan blades. In general, as a compared between the efficiency and cost, five to 12 blades are good practical solutions. Barve et al. (2014) illustrated about design the fan and analyze it for its
strength in structure using the Finite Element Method (FEM) and the flow of air all side it using Computational Fluid Dynamics (CFD) approach. The design of the fan was conducted in phases, starting with calculating to need all dimensions followed by analytical models to prove the concept. The results obtained from the analytical studies determined a potential for a successful design that met greatest of the above outlined parameters. The calculations of the Flow Rate, Static Pressure, Velocity Vectors, and Safety in Structural were made. The structural analysis of the fan represents its strength structurally. The shear stress, Von-Misses 24
stresses approve the safety of the design in structural. Torque Optimization: The maximum torque is optimized for the fan. Its value is 42.5 Nm. Jama et al. (2014) The airflow distribution and non-uniformity across the
radiator of a full size Results from these tests have shown the best method for shielding the front end of the vehicle in terms of airflow equality to be the horizontal way followed by the vertical method. These shielding methods also produced the high average airflow velocity across the radiator which is analogous to better cooling. The results showed that the method to shield the front-end of a passenger vehicle would be to employ a flat method. This shielding method produced the high uniform cooling airflow distribution matched to the other methods. By extension it should also produce the lesser reduction in cooling capacity for a given intake area. Leong et al. (2010) described use of Nano fluids based coolant in the
engine cooling system and its effect on cooling capacity. It is found that Nano-fluid having higher thermal conductivity than base coolant like 50% water and 50% ethylene glycol. It increases heat transfer. So for same heat transfer, radiator core area can be decreased matched to base one. It finds better solution to minimize area. Thermal performance of a
25
radiator using Nano fluids is increased with increase in pumping power required compared to same radiator using ethylene glycol as coolant. Sai et al. (2014) an experimental study of performance of Al2O3 Nano
fluid in a car radiator was studied in the present work. Nano fluids were tested in a car radiator by varying the percentage of nanoparticles mix with the water. Pure water is used in a radiator and its performance was studied. Al2O3 Nano particles are mixed mi xed with the water in 0.025%, 0.05% and 0.1% volume concentration and the performance was studied. The performance comparison has made between pure water and Nano fluids tested in a radiator. The convective heat transfer performance and flow characteristics of Al2O3 nanofluids flowing in an automotive radiator have been experimentally investigated. Impotent increase in heat transfer was observed with the used different volume foci of nanoparticles mixed with water. The experimental result have shown that the heat transfer enhancement was about 4.56% for 0.025% Al2O3 nanofluid at 80ºC and this is about 12.4% for 0.1% Al2O3 nanofluid at 80ºC.The results have shown that Al2O3 nanofluid has a high potential for hydrodynamic flow and heat transfer enhancement in an automotive radiator. Trivedi et al. (2012) illustrated the effect of pitch tube for best
configured radiator for optimum presentation. Heat transfer increases
26
as the surface area of the radiator core is increased. This leads to change the geometry by modifying the order of tubes in automotive radiator to increase the surface area for greater heat transfer. The modification in order of tubes in radiator is carried out by studying the effect of tube pitch by CFD analysis. Results Shows that as the tube pitch this decreased or increased than optimum pitch of tubes, the heat transfer rate increases. So it can suggest that optimum efficiency is coming at the pitch of 12 mm. Yadav et al. (2011) presented parametric study on automotive radiator.
In the action evaluation, a radiator is installed into a test setup. The various parameters including inlet coolant temperature, mass flow rate of coolant, and etc. are varied. Following remarks are observed during learning. Influence of coolant mass flow cooling capacity of the radiator has straightforward relation with the coolant flow rate. With an increase in the value of cooling flow rate, corresponding increase in the value of the effectiveness and cooling capacity. Influence of coolant inlet temperature is increase in the inlet temperature of the coolant the cooling capacity of the radiator increases. Bozorgan et al. (2012) This paper presented a numerical investigation of
the use of copper oxide water nanofluid as a coolant in a radiator of Chevrolet Suburban IC engine with a given heat exchange and pumping
27
power for CuOwater capacity. The local convective overall heat transfer coefficients Nano fluid at different volume fractions (0.1% to 2%) was of the coolant Reynolds number and the studied under turbulent flow conditions. Also the effects automotive speed on the radiator performance are consider in the work. The simulation results indicate that the total heat transfer coefficient of Nano fluid is better than that of water alone and therefore the total heat transfer area of the radiator can be decrease. Nguyen et al. (2007) studied we have experimentally studied the heat
transfer enhancement enhancement delivered by a particular particular nanofluid, Al2O3 water mixture, for a water closed system that is destined for cooling of microprocessors and another heated electronic components. Data obtained for distilled water and Nano fluid with various component concentrations, namely 0.95% and 2.2% & 4.5% have eloquently shown that the use of such a Nano fluid appears especially advantageous for cooling of heated component. For the particular concentration of 4.5%, a heat transfer improvement as much as 23% with respect to that of distilled water has been achieved. Satyamkumar et al. (2006) in this cooling system of automotive engine
the water is evaporate at more temperature, so we need to add water and also water is low capacity of absorb the heat. By using nano fluids in
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radiator alternative of water, we can improve the thermal efficiency of the radiator. So cooling effect of the radiator is improve and the overall efficiency of engine willpower increased. As heat transfer can be improving by nanofluids, in Automotive radiators can be made energy efficient and compact. Vajjha et al. (2010) have been numerically studied a 3D laminar flow and
heat transfer with two different nanofluid, Al2O3 and CuO, in the ethylene glycol/water mixture circulating through the flat tubes of an automotive radiator to evaluate their control over the base fluid. Convective heat transfer coefficient along the flat tubes with the nanofluid flow air considerable improvement over the base fluid. Peyghambarzadeh et al. (2011) have recently investigated the application of Al2O3/water nanofluids in the radiator by calculating the tube side heat transfer co-efficient. They have recorded the interesting enhancement of 45% contrasting with the pure water application under highly turbulent flow condition. Peyghambarzadeh et al. have used diverse base fluids including pure water, pure ethylene glycol and their binary mixtures with Al2O3 nanoparticles and once again it was proved that nanofluids enhances the cooling efficiency of the car radiator extensively.
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Kim et al. (2009) Investigated effect of nanofluids on the performances
of convective heat transfer coefficient of a circular straightforward tube having laminar and turbulent flow with consistent heat flux. This studied have create that the convective heat transfer coefficient of alumina nanofluids enhanced in comparison to base fluid by 15% & 20% in laminar and turbulent flow, separately. This showed that the thermal boundary layer played a dominant role in the laminar flow while thermal conductivity played a dominant role in turbulent flow. Be that as it may no development in convection heat transfer coefficient was noticed for amorphous molecule nanofluids. Naraki et al. (2013) found that thermal conductivity of CuO/water
nanofluids much higher than that of base liquid water. Author found that the total heat transfer coefficient increases with the improvement in the nanofluid focus from (0 - 0.4) vol. %. Conversely, the enactment of nanofluid increases the overall heat exchange coefficient up to 8% at nanofluid focus of 0.4 vol % incomparison with the base fluid.
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3. EXPERIMENTAL WORK 3.1 DESIGN OF AUTOMOBILE RADIATOR IN CREO 2.0 3.1.1 PROPOSED DESIGN
The proposed design of radiator is done as per the standard designing procedure for our project work. It includes the design of radiator model on 3D modeling mechanical software (CREO) its manual calculations, CFD analysis on ANSYS software and its results. CONSIDERED DATA:
Sl.no
1
2
3
4
5
Parameters
Specifiacationss Specifiacation
TOP HEAD LENGTH HEIGHT WIDTH
120mm 20mm 20mm
INLET PIPE DIAMETER THICKNESS
4mm 4mm
TUBE CURVE LENGTH DIAMETER THICKNESS WIDTH
10mm 3mm 2mm 85mm
FIN LENGTH THICKNESS WIDTH
120mm 1mm 20mm
BOTTOM HEAD LENGTH HEIGHT WIDTH
120mm 40mm 20mm
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3.1.2 CREO MODEL
The designed model of radiator is made with the help of CREO software as per dimensions and calculations carried out for our project work. 3.1.2.1 TOP HEAD
FIG.3.1.2.1: 3D Model of Radiator Top Head
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3.1.2.2 TUBE
FIG.3.1.2.2: FIG.3.1.2.2: 3D Model of Radiator Tube 3.1.2.3 FIN
FIG.3.1.2.3: FIG.3.1.2.3: 3D Model of Fin
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3.1.2.4 BOTTOM HEAD
FIG.3.1.2.4: FIG.3.1.2.4: 3D Model of Radiator Bottom Head
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3.1.3 ASSEMBLY
FIG.3.1.3: 3D Model of Radiator using CREO
3.2 CFD ANALYSIS Computational fluid dynamics (CFD) study of the system starts with the construction of desired geometry and mesh for modeling the dominion. Generally, geometry is simplified for the CFD studies. Meshing is the discretization of the domain into small volumes where the equations are solved by the help of iterative methods. Modeling starts with the describing of the boundary and initial conditions
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for the dominion and leads to modeling of the entire system. Finally, it is followed by the analysis of the results, conclusions and discussions.
3.2.1 GEOMETRY Radiator is modified in the ANSYS workbench design module. It is a crossflow heat exchanger. First, the fluid flow (fluent) module from the workbench is selected. The design modeler opens as a new window as the geometry is double clicked. 3.2.1.1 SPACE CLAIM
Check whether there are any stiches. Open the volume extract and select the inlet and outlet to give required fluid domains.
FIG.3.2.1.1: FIG.3.2.1.1: Creation of fluid domain in space claim
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3.2.1.2 DESIGN MODELER
The design modeler opens as a new window as the geometry is double clicked.
Part number
Part Of The Model
State Type
1
FFF\LAMINA_1\LAMINA_1
SOLID
2
FFF\BASE_1\BASE_1 FFF\BASE_1\BASE_1
SOLID
3
FFF\fan fluid domain\Volume
FLUID
4
FFF\rad fluid domian\Volume
FLUID
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