Studying heat transfer with TV-holography

Abstract

A system based on TV holography is proposed for measuring the free convection heat transfer coefficient of a heated metal plate. The aim of this experiment is to familiarize university students of physics and engineering with the practical applications of optical techniques to heat transfer.

Comparative measurements of natural convection heat transfer in channels by holographic interferometry and schlieren

“…Holographic interferometry [7] Heat convection from a plane plate Electronic speckle pattern [8,10] Heat convection from a plane plate [8] interferometry (ESPI) and isothermal diffusion [10] Shadowgraph [13] Heat convection from a horizontal cylinder Digitized images of light path [14] Measurement of refractive index in diffusion experiments Fabry-Perot interferometer (FPI) [11] Description of FPI as an optical feedback system Michelson interferometer [9,16] Determination of refractive index in crystals [9] and detection of invisible interference pattern [16] Ashby and Jephcott interferometer [12] Measurement of loudspeaker membrane moving Microscopic lens effect [15] Determination of refractive index of micro objects A large variety of optical methods is currently employed in experimental heat transfer and fluid flow. Most of them are based on physical principles known since the nineteenth century and their use has mainly been qualitative for several years.…”

“…The EJP Didactic Handbook, based on [7][8][9][10][11][12][13][14][15][16], is summarized in table 1. A web-based learning tool (http://dau.ing.univaq.it/omhat/Ref/schlierenpage.htm) was also developed to accompany this paper offering additional material, real examples from the research world, tutorials and more.…”

Evaluation of diffusion in liquids by digital speckle pattern interferometry: computer simulation and experiments

“…where λ is the wavelength of the light beam, l is the length of the region and n(x, t) = n(x, t 2 ) − n(x, t 1 ) with t 2 = t 1 + t. To measure this phase variation DSPI, also known as TV holography or electronic speckle pattern interferometry, can be used. Detailed descriptions of DSPI are widely available in the literature (Lokberg 1980, Jones andWykes 1989), while an application of the technique in a didactic context can be found in the work of Schirripa Spagnolo et al (1994a).…”

“…In this paper, we present the application of DSPI to diffusion coefficient evaluation, an extensive simulation of the procedure and some experimental results. As has been pointed out (Lokberg 1980, Schirripa Spagnolo et al 1994a, DSPI can be used in vibration, deformation, surface shape and heat transfer measurements; therefore it may become a very useful tool for advanced undergraduate laboratories in experimental physics. The background is usually provided by lecture courses on optics, image processing and numerical analysis.…”