A TECHNIQUE FOR DETERMINING SURFACE TEMPERATURES OF GEOMETRICAL OBJECTS USING CENTER TEMPERATURE VALUES DURING COOLING

An analytical approach is proposed to determine surface temperatures o f objects of various geometrical shapes (e.g., infinite slab, infinite cylinder and sphere) cooled in any medium using their measured center temperature distributions. This approach utilizes the boundary condit ion of the third kind in transient heat transfer which is commonly enc ountered when 0.1<Bi<100, in industrial applications, surface temperat ure measurements of such objects are difficult and require excessive i nstrumentation and operations, as well as more instrumentation time. I n addition they may not be as accurate as desired. However, the measur ement of center temperatures is easy and inexpensive making this techn ique more common. Determination of the surface temperature distributio n is required for a variety of industrial applications from metal-quen ching to cooling food products. This study shows that the proposed app roach is capable of determining surface temperatures of various geomet rical objects, subjected to cooling, using their measured center tempe rature data in a simple and accurate manner.