Evaluation of anisotropic tangential conduction in printed-circuit-board heated-thin-foil heat flux sensors

The effect of the tangential conduction contribution in a thermally anisotropic heated-thin-foil heat flux sensor is examined. A parameter to assess the degree of importance of tangential conduction in the sensor is defined and evaluated in order to justify the need of tangential conduction corrections. Printed circuit boards (PCBs) are typical examples of sensors with anisotropic thermal conduction properties, due to the different conductance values in the directions either parallel or orthogonal to the copper tracks which are placed onto a fiberglass substrate. A parametric study on PCBs with different tracks coverage fraction and copper-to-fiberglass heat conductance ratio is carried out. A revised heated-thin-foil formulation, including a correction for anisotropic thermal properties of the PCB, is experimentally tested. The selected thermo-fluid-dynamic test case is the convective heat transfer of a normally impinging round jet for which axisymmetric maps of the Nusselt number are expected. The anisotropic tangential conduction results in non-axisymmetric temperature distributions. Consequently, if anisotropy is not properly accounted for, non-axisymmetric Nusselt number maps are obtained. The anisotropic conduction effects are shown to be weakly sensitive to the copper tracks coverage fraction while strongly dependent on a parameter called degree of anisotropy, which accounts for the copper-to-fiberglass heat-conductance ratio. Anisotropic conduction effects are found to be almost negligible in PCBs with low values of the degree of anisotropy and/or low values of the tangential conduction degree of importance. Accounting for the anisotropic tangential conduction in the heated-thin-foil formulation allows minimizing the differences between the Nusselt number profiles measured in the directions parallel and orthogonal to the copper tracks

IR wall heat transfer in swirling impinging jets

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Infrared Thermography to an Aluminium Foam Sandwich Structure Subjected to Low Velocity Impact Tests

Abstract This work is the straightforward continuation of previous ones in which vibro-acoustic characteristics of AFS panels were investigated both numerically and experimentally. Herein, the use of infrared thermography (IRT) is exploited to investigate impact damaging of an aluminium foam sandwich panel by monitoring its surface, opposite to the impact, during a low velocity impact test, which is performed with a modified Charpy pendulum. Thermal images, acquired in time sequence during the impact by the infrared camera, are post-processed to get information useful for understanding absorption capabilities and impact damaging mechanisms of this kind of structure

Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography

[EN] Historic buildings have a great cultural and architectural value. It is necessary to analyze their state of conservation, but sometimes it is difficult to perform laboratory tests without damaging this heritage. In the field of architecture, infrared thermography is usually used to provide descriptive information about the surface temperature of building materials. This current research presents a methodology widely applicable to historic buildings. As an example of application, the study is focused in the Seminary-School of Corpus Christi of Valencia (Spain), a very outstanding building from the 16th Century. This research presents an analytical study to be able to differentiate the temperature distribution of all pixels of a thermographic image. Thermal images are a matrix of data and their study helps us in decision-making based on objective data.Lerma Elvira, C.; Mas Tomas, MDLA.; Gil Benso, E.; Vercher Sanchis, JM.; Torner-Feltrer, MEM. (2018). Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography. Russian Journal of Nondestructive Testing. 54(8):601-609. https://doi.org/10.1134/S1061830918080065S601609548Avdelidis, N.P. and Moropoulou, A., Applications of infrared thermography for the investigation of historic structures, J. Cult. Heritage, 2004, no. 5, pp. 119–127. doi 10.1016/j.culher.2003.07.002Barreira, E. and Freitas, V., Evaluation of building materials using infrared thermography, Constr. Build. Mater., 2007, vol. 21, pp. 218–224. doi 10.1016/j.conbuildmat.2005.06.049Bauer, E., Pavón, E., Barreira, E., and Kraus, E., Analysis of building façade defects using infrared thermography: Laboratory studies, J. Build. Eng., 2016, no. 6, pp. 93–104. doi /doi 10.1016/j.jobe.2016.02.012Binda, L., Cardani, G., and Zanzi, L., Nondestructive testing evaluation of drying process in flooded full-scale masonry walls, J. Perform. Constr. Facil., 2010, pp. 473–483. doi 10.1061/(ASCE)CF.1943-5509.0000097Cañas, I., Martín, S., and González, I., Thermal-physical aspects of materials used for the construction of rural buildings in Soria (Spain), Construct. Build. Mater., 2005, vol. 19, pp. 197–211. doi 10.1016/j.conbuildmat. 2004.05.016Carlomagno, G.M., Maio, R., Fedi, M., Meola, C., Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys, J. Geophys. Eng., 2011, vol. 8, pp. 93–105. doi 10.1088/1742-2132/8/3/S09Cerdeira, F., Vázquez, ME, Collado, J., and Granada, E., Applicability of infrared thermography to the study of the behavior of Stone panels as building envelopes, Energy Build., 2011, vol. 43, pp. 1845–1851. doi 10.1016/j.enbuild.2011.03.029EN 13187:1998. Thermal performance of buildings. Qualitative detection of thermal irregularities in building envelopes. Infrared method (ISO 6781:1983 modified).Galarza Tortajada, M., La tapia valenciana: una técnica constructiva poco conocida, Proc. First Natl. Congr. Construct. Hist., Madrid, 1996.Grinzato, E., Bison, P.G., and Marinetti, S., Monitoring of ancient buildings by the thermal method, J. Cult. Heritage, 2002, vol. 3, pp. 21–29. doi 10.1016/S1296-2074(02)01159-7Ibarra-Castanedo C., Sfarra, S., Ambrosini, D., Paoletti, D., Bendada, A, and Maldague, X., Diagnostics of panel paintings using holographic interferometry and pulsed thermography, Quant. Infrared Thermogr. J., 2010, vol. 7, no. 1. doi 10.3166/qirt.7.85-114Lagüela, S., Martínez, J., Armesto, J., and Arias, P., Energy efficiency studies through 3D laser scanning and thermographic technologies, Energy Build., 2011, vol. 43, pp. 1216–1221. doi 10.1016/j.enbuild.2010.12.031Lerma, C., Mas, Á., Gil, E., and Galiana, M., An analytical procedure for the study of the documented construction process of the Seminary-School of Corpus Christi in Valencia (Spain), Inf. Constr., 2014, vol. 66 (533), e007. doi 10.3989/ic.12.117Lerma, C., Mas, A., Gil, E., Vercher, J., and Penalver, M.J., Pathology of building materials in historic buildings. Relationship between laboratory testing and infrared thermography, Mater. Constr., 2014, vol. 64 (313), e009. doi 10.3989/mc.2013.06612Lerma, J.L., Cabrelles, M., and Portalés, C., Multitemporal thermal analysis to detect moisture on a building façade, Construct. Build. Mater., 2011, vol. 25, pp. 2190–2197. doi 10.1016/j.conbuildmat.2010.10.007Madruga, F.J., Ibarra-Castanedo, C., Conde, O., López-Higuera, J.M., and Maldague, X., Infrared thermography processing based on higher-order statistics, NDT&E Int., 2010, vol. 43, pp. 661–666. doi 10.1016/j.ndteint.2010.07.002Meola, C., Infrared thermography of masonry structures, Infrared Phys. Technol., 2007, vol. 49, no. 3, pp. 228–33. doi 10.1016/j.infraredPosta, J., Dolejs, J., Non-destructive assessment of timber elements with an emphasis on radiometry., Intern. J. Arch. Herit., 2015, vol. 9, no.6.Válek, J., Kruschwitz, S., Wöstmann, J., Kind, T., Valach, J., Köpp, C., and Lesák, J., Nondestructive investigation of wet building material: Multimethodological approach, J. of performance of Constructed Facilities, pp. 462–472. doi 10.1061/(ASCE)CF.1943-5509.000005

Application of Thermography to Thermo-Fluid_Dynamics

CD-Rom of the pre-conference course at the 8th AITA 2007, Leon, Mexico (2007