Heat Conduction in One Dimension

Heat transfer is a method or process that indicates the flow of thermal energy through higher to lower energy substances for transfer. Heat transfer is part of thermal engineering. It is also known as diffusion, a direct microscopic exchange of kinetic particles or molecules through a boundary between two systems. 

This chapter is based on transfer modes, heat conduction, equations, and factors that affect excellent transfer with examples. Among different modes, heat conduction is the part where heat occurs along with one different body temperature product and another body of its surroundings. Heat flows in the second product until the surrounding body reaches the same heat level or reaches thermal equilibrium. 

Modes of heat transfer 

Heat transfers from higher to lower temperatures. Though the hat transfer procedure looks simple, it isn’t straightforward. Heat transfer has three different modes. 

• Conduction mode
• Convection mode
• Radiation mode

Conduction mode is the process where it occurs at the microscopic level. The molecules and atoms with a higher temperature also have a high energy level. This energy passes through the atoms and molecules of the neighbourhood area through vibration. Therefore, in simple terms, the conduction mode of transfer includes vibration molecules and atoms as a part of energy transfer. 

Convection is a mode of transfer where molecules and atoms move through collective masses of heat. It requires an actual flow of material, and heat transfer takes place through advection and diffusion. 

Now, if we talk about radiation, this is a process of transfer that takes place through a vacuum, and therefore, it does not need any physical medium of transfer. Generally, this occurs through vacuum or transparent mediums. The process of radiation takes place through photons present in electromagnetic waves. The random moving atoms and molecules create a hard substance, hence its emission in electromagnetic waves, which carries the heat to be transferred. 

Definition of heat conduction

Among the three modes of heat transfer, the conduction mode is the most popular and well-known model. In simpler words, it is a heat transfer process through physical contact. For example, when we press our hands-on windowpane when we place an iron on fire or put a pot of water on an active element, the heat transfers through conduction mode. 

From one body to another, heat transfer occurs from the molecular level. The molecules move more quickly when this heat gets absorbed by a surface. The heat conduction depends on four primary factors:

• temperature gradient
• a cross-section of materials
• the length of the path
• properties of the materials 

Materials that are poor as conductors are known as insulators.   Air is known as an insulator as the conductor power of the air is 0.006. Other natural insulators are feathers, fur, and fibres; these materials help keep warm. 

Factors that affects heat conduction

Several factors affect the thermal conductivity and the energy rate. Some factors that create the most effect on energy transfer is 

Material: the properties of the material being used as the conductor of the heat transfer medium affect the temperature flow rate in two regions. The energy flow will increase when the material of the conductor is more significant. Helium is an excellent conductivity material that exists at shallow temperatures. Other high conductivity materials are diamond, silver, copper, graphite, gold, etc. 

Length: The length of the medium also affects the rate of flows. The shorter the length, the greater the flow. It also increases when the length grows or increases. It just has to increase at a slower pace than usual. 

Temperature: when the temperature of the material rises, the conductivity also rises at an increasing rate. 

Cross-section types: the shape of the conductor, such as C and hollow-shaped cross-section, affect the thermal conductivity. C and hollow-shaped carbon fibre act higher than round types. 

List of best conductors of heat

The best conductors of heat in metal, liquid and gas are 

• Metal: copper
• Liquid: mercury
• Gas: air (low conduction)

Though metals are known as the best conductor of heat in solids, almost all metals conduct heat. However, copper is known as the most potent heat conductor among them. 

List of poor conductors of heat 

• Glass
• Plastic
• Rubber
• Wood
• Paper
• Cloth 

This is the list of poor conductors of heat. 

Conclusion

Conduction is how heat or electric current moves from one substance to another. One object between them stays as a stationary object throughout the process till it can be affected by different factors. Mathematically, the law of electrical conduction is by Ohm’s law, and heat conduction is by Fourier’s law.  

The paper has covered the basic description of heat conduction with factors that affect the temperature flow and conduction rate. Along with that, different modes of heat transfer via different mediums.