This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionThermal wave step.jpg
English: Schematic of a thermal wavefront as induced by a stepped heat source. The experimental geometry with measurement locations is shown in upper part of image. Graphs at bottom of image show lags in the temperature response as function of distance within the transport medium. The medium is characterized by a heat transfer coefficient and a volumetric heat capacity. Arrows indicate the direction and amplitude of the maximum heat flow between isotherms. Flow amplitudes decline and temperature response times increase versus source distance as a consequence of the the medium's thermal inertia.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the licence, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible licence as the original.