The purpose of this study is the evaluation of transient heat fluxes using thin-film thermometer data. A thin-film temperature sensor operated in transient mode enables very accurate surface temperature measurements (e.g., in turbine blades or in hypersonic wind tunnels), which are obtained because the gauge is non-intrusive and has a high frequency response; however, the complexity of data processing is the major drawback for the popular use of the thin-film sensor. The performances of present methodologies for data reduction are here improved, leading to a new implicit method; in addition, a new numerical concept of data reduction is presented: it includes a comprehensive 1-D finite element model which is convenient both for its capability of dealing with the most general boundary conditions and for the low computational cost as compared to the present transform-based methods. The proposed finite element method can tackle the single- and the double-layer sensor, temperature dependent properties of the sensor and, more importantly, it can be applied when the semi-infinite assumption is no longer feasible; it proved successful in processing prototype signals for Mach numbers in the range 0.02–6. The analytical calculation of the accuracy of all the methods is also new and it prompts a guideline that is useful to design a priori an experiment on rational basis.
Titolo: | Numerical processing of thin-film thermometer data for determining transient heat fluxes |
Autori: | Bertolazzi, Enrico; Battisti, Lorenzo; Trivellato, Filippo |
Autori Unitn: | |
Titolo del periodico: | APPLIED MATHEMATICAL MODELLING |
Anno di pubblicazione: | 2012 |
Numero e parte del fascicolo: | 8 |
Codice identificativo Scopus: | 2-s2.0-84859870395 |
Codice identificativo ISI: | WOS:000303947000026 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.apm.2011.09.089 |
Handle: | http://hdl.handle.net/11572/89230 |
Appare nelle tipologie: | 03.1 Articolo su rivista (Journal article) |