CHARACTERIZATION OF HEAT TRANSFER COEFFICIENT UNCERTAINTY IN SUPPORT OF HIGH TEMPERATURE PROBE MEASUREMENT TECHNOLOGY

The development of new materials and processes have enabled defense, industrial, and research devices that operate in high temperature environments. Measurement technology must keep up with the demand of these environments.

The objective of this work is to provide a correlation between the heat transfer coefficient (and Nusselt Number) and the flow Reynolds number (and Prandtl number) for a truncated cylindrical probe. The correlation provides reduced uncertainty for materials whose heat transfer coefficient is not well defined. The configuration for the experiment uses the University of Tennessee Space Institute’s (UTSI) blow down air supply system discharging into a duct and exhausting to atmosphere. This system provides dry pressurized air that is used at the supply thermally stabilized total temperature to the test section. The test article is a heated probe that is instrumented with thermocouples. Experimental data were recorded for many run conditions. These data were utilized to develop the correlation between the heat transfer coefficient and the Reynolds number.

As a result of the work presented in the body of this text a correlation between the heat transfer coefficient and the Reynolds number was developed with an uncertainty of 1.24%.