An Ultimate Guide to Heat Transfer

Any object or substance consisting of atoms or molecules inside tends to transfer heat across the system’s border. The transfer of heat process begins with a difference in temperature between a system and its surroundings. Although, the temperature difference is often known as the potential mainly responsible for the shift in thermal energy. The greater the number of molecules an object will have, the higher will be the heat energy. There are many ways to transfer the heat from one location to another, including conduction, Convection, and Radiation. This article will discuss all of them in brief. 

What do you mean by heat transfer?

The thermodynamic system in physics defines heat transfer as the movement of energy across various border systems due to the temperature difference in its surroundings. It generally occurs from a hot object to a cold object. The occurrence of heat change brings a change in the internal energy of the systems involved in the change. 

Ways of heat transfer 

 There are three ways of transferring from one object to another. It involves conduction, convection, and radiation. You can read their description from the information mentioned below. 

Conduction: Meaning and concept 

Conduction refers to the transfer of heat or energy from one object or system to another. It occurs because the molecules in the object begin vibrating at their mean positions. Although to transfer the heat from one system to another, the figures through which it takes place must be placed in close contact with each other. 

Also, there is no movement in a matter that occurs during the transfer of heat from one location to the other in the conduction process. It generally arrives in the solids in which the molecules present in the structure are held tightly by strong intermolecular attraction forces. Therefore, they only vibrate in their mean places when they receive and pass the heat energy through vibrations to their surrounding molecules. 

Meaning of Convection and concept 

Convection refers to transferring heat or energy in the form of liquid or gaseous states. It generally takes place on the actual movement of the matter from one place of the body to another. The experiment of boiling water, occurrence of bubbles, and current is a great example of the convection process. Do you know why? The hot water at the vessel’s bottom turns lighter and begins moving upward. It pushes the colder and dense water to get heated up from the reaction. 

The transfer of energy in the convection process takes place through a fluid. The energy is always transferred from high to lower temperatures for respective areas. However, the moving matter makes the heat transfer by forming convection currents. 

Radiation: Meaning and concept 

 Radiation is the third way of transferring energy from one substance to another. The radiation heat transfer method does not require any medium. The method is very useful for energy exchange in a vacuum. It also uses electromagnetic waves that conduct the heat exchange process from one location to another. One of the best examples of the radiation method is the sunlight, in which the heat and the light reach the earth from the sun throughout the whole process. Although, it is the most influential form of heat transfer. 

It is the radiation method that only makes you feel warmer whenever you come in close contact with fire in winters without touching it properly. Henceforth, in some other way, everyone is a part of the radiation process in their daily lives. Mainly the electromagnetic waves in the radiation heat generated by its emissions. The waves then carry the heat from the emitting object in liquid or solid forms. It is the outcome of random movement of molecules, measured by a thermocouple device often useful for measuring temperature. 

Factors affecting heat transfer

The rate of heat transfer depends on the following factors:

• Temperature across the object
• Cross-sectional area of the object 
• Time
• Length

1. 1. Temperature across the object– Temperature is paramount when thinking of a heat transfer method. The higher the difference between two ends of a bar, the higher the thermal energy transfer will be. Although, the heat is proportional to the temperature difference. The heat is derived by Q. 
2. Cross-sectional area of the object– A double-wide bar, conducting the amount of heat twice. The amount of energy or heat is proportional to the cross-sectional area of the material. Heat is derived by Q, and the area is derived by A. 
3. Time– The amount of heat exchange Q relies on the time passed in the conductionprocess. 
4. Length– The length of an object plays a vital role in heat transfer. The longer the object, the less heat it will generate throughout the process. Thereby, the heat is inversely proportional to the object’s length. 

Conclusion 

Heat transfer is an easy process across the border of the system consisting of atoms and molecules. Generally, a heat transfer occurs when there is a change in temperature and its surroundings within the system. The conduction method is the first to organize the heat transfer process, followed by convection and radiation methods. Among these, radiation is the most common way of transferring heat from one to another through sunlight radiant rays. Such heat exchange depends on the cross-sectional area, temperature, time, and length of the bar in which one conducts the heat.