Examination of heat transfer in autoclaves

摘要

The heat transfer in an industrial autoclave environment was examined. While heat transfer coefficients for simple shapes, such as flat plates parallel to an airflow, and cylinders can be predicted theoretically, those for complex contoured composite parts are not easily predicted. In this study, the autoclave heat transfer for flat plates at various angles, axial and horizontal position in a composites processing autoclave was examined. This information is required to predict the heat transfer coefficients for complex composite parts. Flat plate calorimeters, each instrumented with 8 thermocouples were used to obtain heat transfer measurements for various locations and angles within the autoclave. An autoclave constant was developed and measured for one autoclave. It was found that the front of the autoclave had higher heat transfer than the back. Higher heat transfer rates were observed at the front of the autoclave as compared to the back and on its left side relative to its right side. The heat transfer rate into an inclined plate was found to depend primarily on the plate angle relative to the freestream and secondarily on the plate angle relative to the autoclave axis. General equations for a model to predict the observed trends were developed.