A Numerical Investigation of Thin-Film Heat Transfer Gages
Abstract
When using a thin film gage to measure surface heat flux, one typically reduces the data for surface temperature to surface heat flux using a series solution for one-dimensional heat transfer in an initially isothermal, semi-infinite solid. However, the gage may not behave as an initially isothermal, semi-infinite solid due to multidimensional heat transfer and electrical preheating of the gage when the instrumentation is turned on. To evaluate the accuracy of the series solution for use with thin-film gages, the heat transfer in a gage was numerically simulated using a two-dimensional, finite-difference model. The actual geometry of the probe was simplified to reduce the heat transfer to two dimensions. The simulation produced surface temperatures which were used in the series solution to find estimates of surface heat flux. The heat fluxes from the simulation and the series solution were then compared to evaluate the accuracy of the series solution. The analysis provides good insight into the causes of inaccuracies when using the series solution. It also provides some quantitative results which may be helpful for estimating errors in actual laboratory use. Theses
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1989
- Accession Number
- ADA206134
Entities
People
- Joseph A. Bonafede
Organizations
- Air Force Institute of Technology