ABSTRACT
The rate of heat transfer by a cooling fin varies with time in response to changes in the operating conditions of the attached devices. A solute in a region of high concentration will diffuse to the neighboring regions as time progress. Similarly, vorticity of fluid motion also diffuses from layers of high intensity to the surrounding fluid due to molecular viscosity. Dissolved oxygen concentration (or tension) diffuses in tissues and cells where it is consumed. The basic principles of continuum mechanics provide mathematical models for the space‐time distributions of temperature in fins, concentration of solutes, vorticity of fluids, and oxygen tension in tissues. Simplified mathematical models for the aforementioned phenomena and other applications in transient heat and mass diffusion give rise to parabolic equations.
