September 2, 2024
Thermophysical properties play a crucial role in modern engineering and science. By understanding and leveraging these properties, materials can be optimized to enhance thermal performance and drive innovation across various applications.
The selection of materials for specific applications entails not only their design and optimization but also consideration of their thermophysical characteristics. Knowing how a material will act to changing thermal conditions is pertinent in areas such as construction, manufacturing, and energy generation. In this blog, we will discuss thermophysical properties and how we use them in various realms.
Thermophysical properties are characteristics of a substance that indicate how it responds to temperature changes. These properties also show the substance’s ability to conduct, store, and release heat. It also determines how a material behaves when its thermal state is altered.
Therefore, understanding these properties enables us to predict how materials will react when exposed to a change in temperature. These properties include thermal conductivity, specific heat, thermal expansion, and others.
Thermal conductivity refers to the ability of a material to conduct heat. Metals for example are good conductors of heat, which means they can transfer heat quickly. However, insulators such as plastic transfer heat slowly because they have a low thermal conductivity.
Figure 1: Metals are good conductors of heat, and that’s why they can be used in cooking
Specific heat capacity is the amount of heat energy required to raise the temperature of one unit of mass of a particular material by one degree Celsius. In other words, substances with high specific heat capacities, like water, can absorb a lot of heat energy with only a slight increase in temperature. A metal such as lead exhibits a low specific heat capacity, requiring much less heat energy to increase its temperature.
Thermal expansion measures how much a material’s size changes when its temperature changes. Normally, most materials tend to expand when exposed to heat or contract when exposed to the cold.
Figure 2: Many materials are likely to go through expansion in the high temperatures as indicated and contraction in the low temperatures.
The thermal conductivity of a material indicates how well it will conduct heat. For this reason, engineers test thermal conductivity to determine the right materials for their project. For example, one would need a good conductor with high thermal conductivity for a heat transfer system, whereas an insulating material with low thermal conductivity would be used for a furnace lining.
These properties, therefore, guide engineers and professionals to manufacture products and create systems that can withstand a wide range of temperatures. A good example of this is the application of thermal interface materials (TIMs), such as aluminum or copper, to reduce the thermal resistance of solar panels.
Different materials demonstrate unique thermal properties that make them ideal for particular uses. Here are some examples from the material database:
Water: Water is known for having a high specific heat capacity . In simpler words, it can store a lot of heat without much change in temperature. Which is why it is used to make cooling systems.
Figure 3: Thermal properties of water
Metals: Metals like copper and aluminum are good heat conductors and can be used for the same reason, either in heat exchangers or in cooking equipment.
Figure 4: Thermal properties of copper
Plastics: Plastics are poor heat conductors and have a high specific heat capacity, which makes them great insulating materials.
Figure 5: Thermal properties of Plastic
The material’s thermal properties need to be known for their proper application in various industries. In construction, it applies to understanding the materials good for insulation needed in energy conservation.
On the other hand, the manufacturing industry requires materials that fit at various extreme temperatures without changing their shape or size, which is why thermal expansion is an important characteristic. Therefore, it is of utmost importance to have the right instruments that can accurately measure these properties.
Thermophysical properties play a vital role in many fields, influencing the design and functionality of materials and systems. Here are some applications:
Materials Science: Scientists look at the properties of new materials to make better products. This includes materials that can handle hot temperatures or conduct heat well for electronic devices. The new composites, with special thermal properties, can be strong and not expand much when heated. These materials are perfect for the aerospace and car industries, where they need to handle temperature changes.
Energy Production: Materials with good thermal conductivity in the heat exchangers of power plants help improve energy efficiency. It is important to know the specific heat capacity of these systems when designing better ways to store heat.
For instance, fluids like water or certain salts that can hold a lot of heat are used to store thermal energy well in energy systems. This is useful in solar power plants where extra heat can be stored and used later when the sun isn’t shining, which makes the energy system more efficient overall. (Rashid, 2019)
Engineering: Mechanical and civil engineers look for materials with specific thermal properties to guarantee safety and efficiency. For instance, construction materials such as foam or fiberglass have poor thermal conductivity, thus reducing the rate of heat loss and making the buildings more energy efficient.
Figure 6: Fiberglass is widely used as an insulator since it has low thermal conductivity, which helps reduce heat loss.
Thermophysical properties are cornerstones of modern engineering and science. Consequently, developments in this area are important for enabling more economic and sustainable materials and systems. Advancements in technology have rapidly increased the importance of understanding these properties to enable the creation of materials with tailored characteristics for different applications.
It demands an optimum mix of experimental, theoretical, and computational approaches toward the understanding of this for innovation. Such a piece of knowledge will drive industries ahead on fronts related to energy efficiency, electronic cooling, and material science.
Make sure your research and application depend on very accurate data. Use apex instruments for the most precise measurements of thermal properties. Explore Thermtest’s product line to find the right tools for your needs.
Grimvall, G. (1999). Thermophysical Properties of Materials. Sweden: Elsevier Science.
Heat, Work and Energy. (2003). Retrieved from Engineering ToolBox: https://www.engineeringtoolbox.com/heat-work-energy-d_292.html
Juan J. Valencia, P. N. (2008). Thermophysical Properties. ASM International.
Rashid, F. A. (2019, October). Thermal Energy Storage in Solar Power Plants: A Review of the Materials, Associated Limitations, and Proposed Solutions. Retrieved from MDPI: https://doi.org/10.3390/en12214164