Can fins decrease heat transfer?

Fins enhance heat transfer from a surface by increasing heat transfer surface area for convection heat transfer. However, adding too many fins on a surface can suffocate the fluid and retard convection, and thus it may cause the overall heat transfer coefficient and heat transfer to decrease.

What is the purpose of using fins in a particular heat transfer system?

Explanation: Fins are provided to a heat exchanger surface to augment the heat transfer by increasing the surface area exposed to the surroundings.

How does heat transfer increase fins?

Fins are extensions on exterior surfaces of objects that increase the rate of heat transfer to or from the object by increasing convection. This is achieved by increasing the surface area of the body, which in turn increases the heat transfer rate by a sufficient degree.

What is effectiveness of fin?

the ratio of actual heat transferred from fin area to the heat which would be transferred if entire fin area was at base temperature.

How can fin efficiency and fin effectiveness be improved?

Factors affecting fin effectiveness

1. P.Kh.Ac should be greater than unity if the rate of heat transfer from the primary surface is to be improved.
2. If the ratio of P and Ac is increased , the effectiveness of fin is improved.
3. Use of fin will be more effective with materials of large thermal conductivities.

What is fin efficiency What does it depend upon?

The fin temperature effectiveness or fin efficiency is defined as the ratio of the actual heat transfer rate through the fin base divided by the maximum possible heat transfer rate through the fin base, which can be obtained if the entire fin is at base temperature (i.e., its material thermal conductivity is infinite).

What is the purpose of using fins?

Uses. Fins are most commonly used in heat exchanging devices such as radiators in cars, computer CPU heatsinks, and heat exchangers in power plants. They are also used in newer technology such as hydrogen fuel cells.

Why parabolic fins are preferred in heat transfer device?

1. The fins will be hotter at the base than at the edges . 2. the air will flow with higher velocity at the edges and may escape .

Why are fins used?

Fins are thus used whenever the available surface area is found insufficient to transfer required quantity of heat with available temperature gradient and heat transfer coefficient. In the case of fins the direction of heat transfer by convection is perpendicular to the direction of conduction heat flow.

What is the use of fins?

Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fins are also used to increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fish as a means of locomotion.

What affects fin efficiency?

Factors affecting fin effectiveness P.Kh.Ac should be greater than unity if the rate of heat transfer from the primary surface is to be improved. If the ratio of P and Ac is increased , the effectiveness of fin is improved. Use of fin will be more effective with materials of large thermal conductivities.

What is fin effectiveness and fin efficiency?

2 Fin Efficiency and Surface Effectiveness. Fin efficiency is defined as the ratio of actual heat flow of the fin to that which would be obtained with a fin of constant temperature uniformly equal to the base surface temperature, that is, one with infinite thermal conductivity.

How do cooling fins work?

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. The design of cooling fins is encountered in many situations and we thus examine heat transfer in a fin as a way of defining some criteria for design.

What are the applications of a heat fin?

Fins are used in a large number of applications to increase the heat transfer from surfaces. 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

What is the heat transfer coefficient at the end of a fin?

The end of the fin can have a different heat transfer coefficient, which we can call . The approach taken will be quasi-one-dimensional, in that the temperature in the fin will be assumed to be a function of only. This may seem a drastic simplification, and it needs some explanation.

What is the direction of the heat flow in the fin?

There is heat flow of magnitude at the left-hand side and heat flow out of magnitude at the right hand side. There is also heat transfer around the perimeter on the top, bottom, and sides of the fin.