Does increasing surface area increase heat transfer?

Heat transfer rate is directly proportional to the ‘available surface area’ for heat transfer. BUT the effect of that heat transfer also depends on the volume. Generally, it is better to consider the (surface area / volume) ratio when designing a heat transfer system.

What is the purpose of attaching fins to a surface?

Longitudinal or radial fins are attached to a bare surface to enhance heat flow rate from a surface to an adjacent fluid. Fins are used when the convection heat transfer coefficient h is low, as is frequently the case for gases such as air or flue gas [1, 2, 3, 4, 5, 6, 7, 8, 9].

How do you increase heat transfer in heat exchanger?

Increasing heat exchanger performance usually means transferring more duty or operating the exchanger at a closer temperature approach. This can be accomplished without a dramatic increase in surface area. This constraint directly translates to increasing the overall heat transfer coefficient, U.

What is purpose 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 is fin in heat transfer Slideshare?

Introduction • Fins are generally used to enhance the heat transfer from a given surface • Addition of fins can increase the heat transfer from the surface by several folds • In many engineering situation, means are often sought to improve heat dissipation from a surface to its surrounding • Whenever the available …

How does heat transfer increase?

If the temperature difference on opposite sides of the material through which heat is transferred is increased by a factor of 2, then the rate of heat transfer is increased by a factor of 2.

How does surface area affect heat?

Short answer: In most cases, heat loss is roughly proportional to surface area. That means: Double the surface area, double the heat loss.

What is the purpose of using fins in a particular heat transfer system coolers of heat engines identify the correct answer?

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

What affects heat transfer in heat exchanger?

Heat transfer performance of heat pipe heat exchanger affected by many factors, such as the opening temperature of the heat pipe, the rate of fluid-filled, the physical nature of liquid refrigerant, the work temperature of tube, angle, tube spacing, tube length, hot and cold fluid flow and wind speed.

How do you increase fin effectiveness?

Since the fin efficiency is inversely proportional to Λ, it can be improved either by increasing k and B, or by decreasing 〈h〉 and L. If the average heat transfer coefficient, 〈h〉, is increased due to an increase in the air velocity past the fin, the fin efficiency decreases.

What are the types of fins in heat transfer?

1) Constant Area Straight Fin 2) Variable Area Straight Fin 3) Pin Fin 4) Annular Fin

• Constant Area Straight Fin.
• Variable Area Straight Fin.
• Pin Fin.
• Annular Fin.

What is the function of fins in heat transfer?

Heat transfer by convection between a surface and the fluid surrounding can be increased by attaching to the surface called fins. The heat-conducting through solids, walls, or boundaries has to be continuously dissipated to the surroundings or environment to maintain the system in a steady-state condition.

How do fins increase the effective area of a surface?

The fins increase the effective area of a surface thereby increasing the heat transfer by convection. Rectangular fin and triangular fins are straight fins. Triangular fins are attractive, since for an equal heat transfer it requires much less volume than rectangular fins.

How do finned surfaces enhance heat transfer?

Fins enhance heat transfer from a surface by exposing a larger surface area to convection and radiation. Finned surfaces are commonly used in practice to enhance heat transfer, and they often increase the rate of heat transfer from a surface several fold. The car radiator shown in Fig.

How to increase the heat transfer rate of the fluid?

HTC of the fluid inside the cylinder is higher than the HTC of fluid on the outer surface of the cylinder. It is okay to apply fins on both surfaces of pipes or tubes when HTC of fluid on the inner and the outer surface is comparable in magnitude. By using the fins, the heat transfer rate can be increased without any preventive maintenance.