Experiments in Heat Transfer Under Conditions of

Correlations developed for steady pressure and flow to predict heat transfer are inadequate under conditions of oscillating both pressure and flow. This has been shown both theoretically and experimentally. Since almost every reciprocating energy conversion machine operates in an oscillating environment, and heat transfer has a significant effect on engine efficiency, it is imperative that mathematical correlations should be developed to predict heat loss through the walls of components within these systems. A large heat transfer apparatus was built in 1990 to stimulate the oscillating environment found in Stirling engines. Later modifications to the apparatus allow more accurate measurements of velocity, pressure, centerline temperature, wall temperature, and heat flux. It is also capable of capturing temperature and velocity profiles across the diameter of the test section. This work addresses the collection of baseline data under conditions of oscillating pressure and flow by (a) investigating the disappearance of seeding particles at a certain part of the cycle, (b) continuing the experiment for a wider range of conditions, and (c) recording and analyzing baseline heat transfer data