TABLE OF CONTENTS As can be seen in a number of calculations presented earlier in this handbook, heat-transfer coefficients play a key role. Their determination can be difficult in instances in which surface geometries are complex or surfaces are fouled or corroded. This brief part consists of two chapters, both by academics. The first confronts geometrically complex surfaces exposed to convection by using liquid crystal or infrared thermography in conjunction with a semi-infinite solid assumption. Where there is buildup of scale or contamination around the tubes of a heat exchanger, or corrosion of internal baffles alters the individual film coefficient for heat transfer on the side affected, determining individual film coefficients experimentally is simplified by a method called the Wilson analysis; this is described in the second chapter.
Srinath V. Ekkad
Mechanical Engineering Department
Louisiana State University
Baton Rouge, Louisiana
Two-dimensional surface heat-transfer distributions on convective surfaces provide a complete picture for complex flow-solid interactions in heat transfer. The semi-infinite solid assumption provides an opportunity to obtain detailed surface heat-transfer behavior using thermography. Typically, liquid crystal or infrared thermography is used in conjunction with the semi-infinite solid assumption.
The local heat-transfer coefficient h over a surface coated with liquid crystals can be obtained by using a one-dimensional (1D) semi-infinite solid assumption for the test surface. The 1D...
