An ideal fin is the one whose temperature is equal to temperature of the surface. This is possible only if the thermal conductivity of fin material is infinitely high. The effectiveness of an actual fin material is always lower than an ideal fin.
What is fin efficiency formula?
The fin heat transfer is determined by using fin efficiency. … The fin efficiency is defined by the division of the actual by the theoretical heat transfer, that is, (9.35) η = ϕ actual ϕ theor = G θ t h A s θ t = G h A s . The actual heat flow through the fin is. (9.36) ϕ actual = G θ t = h η A s θ t .
How efficient are fins?
The efficiency of a fin is defined as the ratio of the actual heat transfer from the fin to that the heat that would be dissipated if whole surface of the fin is maintained at base temperature.
What do you understand by annular fin?
In thermal engineering, an annular fin is a specific type of fin used in heat transfer that varies, radially, in cross-sectional area. … Because surface area increases as length from the object increases, an annular fin transfers more heat than a similar pin fin at any given length.
Which medium is better for fin effectiveness?
The use of fins is most effective in applications involving low convection heat transfer coefficient. Thus, the use of fins is more easily justified when the medium is a gas instead of a liquid and the heat transfer is by natural convection instead of by forced convection.
What is fin efficiency used for?
Fin efficiency, η This quantity is more often used to determine the heat flow when variable area fins are used. Fin efficiency is defined as the ratio of heat dissipation by the fin to the heat dissipation takes place if the whole surface area of the fin is at the base temperature Tw.
Which material is ideal for making a fin?
Aluminium is one of the most frequently used materials for fin due to its higher thermal conductivity and comparatively low cost. Triangular shape is best from point of view of heat transfer to weight ratio.
What is fin performance?
Fin performance can also be characterized by fin efficiency. This is the ratio of the fin heat transfer rate to the heat transfer rate of the fin if the entire fin were at the base temperature, in this equation is equal to the surface area of the fin.
What is an ideal fin?
An ideal fin is the one whose temperature is equal to temperature of the surface. This is possible only if the thermal conductivity of fin material is infinitely high. The effectiveness of an actual fin material is always lower than an ideal fin.
Where are annular fins used?
Radial (annular) fins are often attached to the cylindrical surfaces to increase the rate of heat transfer from the cylindrical surface to the ambient. Traditional applications have included internal combustion engines, compressors, heat exchangers and control systems.
Which type of design of fins is more effective?
The rectangular fin with single-step change has been found to be the most efficient fin profile in terms of maximum heat loss and fin efficiency.
What is longitudinal fin?
Longitudinal fins within ducts are widely used in compact heat exchanger applications. Such ducts are also referred to as internally finned tubes. … For the flow area evaluation, the fin thickness is considered as zero for all longitudinal thin fins.
What is effect of thermal conductivity on fin effectiveness?
10a-d shows that the fin efficiency decreases monotonically (for different thermal conductivity and at a constant heat transfer coefficient) with increasing thermogeo- metric parameter. Also, it shows the variation of fin efficiency with thermogeometric in longitudinal convecting fin with insu- lated tip.
In which case the efficiency of fin will be maximum?
The effectiveness of a fin will be maximum in an environment with free convection. Explanation: The fin temperature is also known as the fin effectiveness. Thus it is defined as the ratio of the actual amount of the heat transfered to the to the divided base temperature in the serve.
Which one of the following configurations has the highest fin effectiveness?
Which one of the following configurations has the highest fin effectiveness ? Fin effectiveness is defined as the ratio of the fin heat transfer rate to the heat transfer rate that would exist without the fin. And it is highest with Thin and closely spaced fins.
What are the different types of fins?
For each fish, generally, there are five main fins follows: Dorsal, Pelvic, Caudal (tail), Anal and Pectoral as shown in Fig. 1. Dorsal fins are located either on the back of the fish or its top, it helps the fish during sharp turning or stops.
What makes a good fin heat transfer?
Typically, the fin material has a high thermal conductivity. The fin is exposed to a flowing fluid, which cools or heats it, with the high thermal conductivity allowing increased heat being conducted from the wall through the fin.
How is the rate of heat transfer from the infinite fin given?
The rate of heat transfer from a solid surface to atmosphere is given by Q = hA ∆ T where, h and ∆T are not controllable. So, to increase the value of Q surface area should be increased. The extended surface which increases the rate of heat transfer is known as fin.
Which shape of fin is most effective for heat transfer?
Rectangular fin produces the highest heat transfer performances due to the interruption done by the staggered surfaces to the flow and temperature boundary layers along the flow orientation.
What material are fins made of?
Materials Used Nowadays fins are normally made in Plastic or Fiber. Fiber fins are combining different materials to obtain better performance, and better weight and flotation ratios like honeycomb cores, bamboo core, and then glassed with fiber and sometimes reinforced with carbon fiber.
What materials are used for fins?
Most commonly used material for manufacturing of fins is aluminum alloy. Now we are replacing present aluminum alloy with Aluminum alloy 6063 and Aluminum alloy 7068. Dimensions for fins and cylinder have been taken from the standard dimensions.
Why thin fins are preferred over thick fins?
If however we are talking about two fins of the same plan shape and size , but of different thicknesses and thus chord ratios, then the following should apply: a thinner fin will have lower drag at low angles of attack, but is more likely to stall at higher angles of attack and when it approaches the stall it will …
Can fin effectiveness be greater than 1?
Fin effectiveness is defined as the ratio of heat transfer rate from a finned surface to the heat transfer rate from the same surface if there were no fins, and its value is expected to be greater than 1.
What is the difference between fin efficiency and fin effectiveness?
Therefore, the fin effectiveness can be determined easily when the fin efficiency is known, or vice versa. The thermal conductivity k of the fin material should be as high as possible. The overall effectiveness is a better measure of the performance of a finned surface than the effectiveness of the individual fins.
What is pin fin?
Pin fins are used to increase heat transfer from heated surfaces to air. Industrial experience has shown that for the same surface area, pin fins can transfer considerably more energy than straight fins. The analysis of a single pin fin is well known.
How do you calculate fin surface area?
where Af is the fin surface area, Ap is the primary surface area and A = Af + Ap. In Eq. (1), the heat transfer coefficients of finned and unfinned surfaces are idealized to be equal.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.