Heat transfer quantitative characterization: Passive and active methods
Abstract
Two ways of determining the convective fluxes from the nonsteady temperatures are discussed: the passive method of classical thermography, in which the heating due to convection alone is used; and the active method of stimulated thermography in which the heat transfer coefficients are found directly from the heating due to a source of radiation, which is added to the convection for very brief intervals. The various algorithms used for identification of the heat transfer coefficient are presented together with some experimental results. For heat transfer identification, monodimensional models are used in both the passive and active modes. Moreover, considering the fact that supersonic or hypersonic flows are being dealt with, it is assumed that the linearized transfer coefficient corresponding to the radiative transfers between the model and the wind tunnel wall is negligible compared with the convective transfer coefficient.
- Publication:
-
VKI Measurement and Techniques
- Pub Date:
- 1993
- Bibcode:
- 1993VKIMT....S....B
- Keywords:
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- Convective Heat Transfer;
- Heat Transfer Coefficients;
- Radiative Heat Transfer;
- Temperature Measurement;
- Thermography;
- Heat Flux;
- Hypersonic Flow;
- Infrared Imagery;
- Quantitative Analysis;
- Supersonic Flow;
- Wall Flow;
- Wind Tunnel Tests;
- Wind Tunnel Walls;
- Instrumentation and Photography