Machine Parts

Real surfaces on of the best examples are not perfectly diffuse and hence the intensity of emitted radiation is not constant over all directions. The characteristically different behavior of electric conductors and mono-conductors.   Conductors emit more energy in a direction having a large azimuth angle. This behavior more explained with basic electromagnetic wave theory A sphere conducted and mono conducting material will have the opposite behavior and will appear bright in the center and dark around the edge. Reflectance and absorptance of thermal radiation from real surfaces are a function not only of the surface itself but also the surroundings . The properties are dependent on the direction and wave length of the incident radiation .   But the distribution of the intensity of incident radiation with wave length may be a very complicated function of the temperatures and surface characteristics of all the surfaces which incorporate the surrounding

The application of the principles of heat transfer to the design of equipment to accomplish a certain engineering objective is of extreme importance for an applying the principles to design the individual is working toward the important goal of the product development for economic gain.  Economics plays a key of role in the design and selection of heat exchange equipment and the engineering should bear this mind when embarking any new heat transfer design problems. The weight and size of heat exchangers used in space or aeronautical applications are very important parameters and this cases cost considerations are frequently subordinated insofar as material and heat exchanger construction cost are concerned.  The weight and size are important cost factors in the overall   applications in the fields and thus may still be considered as economic variables.                 NASA Helps Build Strong Cities and Communities   Feed gearbox with slee