One-dimensional, steady-state conduction
Tariq Muneer, Jorge Kubie, Thomas Grassie · Heat Transfer · 2012
Fourier was aware that Newton had already observed that the rate at which heat is transferred between regions at different temperatures is proportional to the temperature difference. He conducted simple experiments on steady-state one-dimensional heat flow in solids. These experiments are simple in analytical sense, in that the temperature does not vary with time (steady-state conditions) and that the temperature changes only in the direction of the heat flow (one-dimensional flow condition). Several important properties required for the analysis of conduction heat transfer have been already introduced: thermal conductivity, density and specific heat. These properties are collectively known as thermophysical properties. In many other situations thermal systems exhibit temperature variations in predominantly one direction and insignificant errors are introduced when temperature gradients in other directions are neglected. Such behaviour can be observed in special radial systems, such as cylinders and spheres, and in extended surfaces, which are used to enhance the rates of heat transfer.