Photography techniques

By using a smoke photography technique one of these free vortices (irrota-rionat) in Fig, 10.55 has been visualized (see Fig, 10.56 ... 

Horton (H9, K2), using a tapered tube, was able to match the velocity of fall of the drop with the velocity of the rising field and thereby observe the behavior of the system for an hour or more. Using a dark field trace photography technique, the semi-vectorial velocities were recorded. In every case the internal circulation was slowly damped out as the interface changed its character and became more contaminated. 

A visualization study of fuel atomization using a pulsed laser holography/photography technique indicates that basic spray formation processes are the same for both a coal-derived synthetic fuel (SRC-II) and comparable petroleum fuels (No. 2 and No. 6 grade). Measurements were made on both pressure swirl and air assisted atomizers in a cold spray facility having well controlled fuel temperature. Quality of the sprays formed with SRC-II was between that of the No. 2 and No. 6 fuel sprays and was consistent with measured fuel viscosity. Sauter mean droplet diameter (SMD) was found to correlate with fuel viscosity, atomization pressure, and fuel flow rate. For all three fuels, a smaller SMD could be obtained with the air assisted than with the pressure swirl atomizer. 

Yule et. al. [76] suggest these holographic techniques offer no significant advantage over the relatively simple two-dimensional spark photography technique for measuring particles in sprays. Tyler [77] has reassessed the application of Fraunhofer holography to particle size determination. 

The theoretical expressions describing the mobility of the particle close to a solid wall were verified experimentally by Adamczyk et al. [100] and Malysa and van de Ven [101] using the multiple-fi ame photography technique. 

Especially after the development of the digital photography techniques, logging on the photomosaic of walls has almost become a standard in trench studies. The trench walls are photographed and combined into a mosaic covering the whole wall (Fig. 5). Fast orthorectification of photos provide precise representation of trench exposures. 

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