Soojuskontakt

Soojuskontakt, often translated as thermal contact, refers to the interface between two solid bodies where heat transfer can occur. When two surfaces are brought into contact, they do not perfectly conform to each other at a microscopic level. This leads to small gaps or air pockets at the interface, which significantly impede the flow of heat. The actual area of contact, known as the real contact area, is much smaller than the apparent or nominal contact area. Heat transfer across the soojuskontakt primarily occurs through two mechanisms: conduction through the solid-to-solid contact points and conduction and radiation across the interstitial gaps filled with a fluid, typically air.

The thermal resistance of a soojuskontakt is a measure of how effectively it impedes heat flow. It depends on several factors, including the surface roughness of the contacting materials, the applied pressure between them, the thermal conductivity of the materials themselves, and the properties of the interstitial fluid. Higher pressures generally increase the real contact area, thus reducing thermal contact resistance. Similarly, smoother surfaces and materials with higher thermal conductivity also lead to lower resistance. In applications where efficient heat transfer is crucial, such as in electronic cooling or heat exchangers, minimizing soojuskontakt resistance is a primary design consideration. Techniques like using thermal interface materials (TIMs) are employed to fill the microscopic gaps and improve the overall thermal contact.