Shadowgraph techniques

In backlight or shadowgraph technique, the light comes from behind and is directed toward the camera. This technique is very useful in measuring bubble or drop size distributions (Figure 15.3). 

Figure 15.3 Bubble size measurements using shadowgraph technique (From [9]).

Booster was used to initiate the expl at one end. The radial motion of the cylinder wall was measured in a plane perpendicular to the cylinder axis 7 inches from the booster end, A streak camera recorded the motion, using conventional shadowgraph technique (See under CAMERAS, HIGH-SPEED PHOTOGRAPHIC in Vol 2 of Encycl, p CI3-L). In addn, the deton velocity of the expl was measured by placing pin switches 9-i° apart on the surface of the cylinder, as described, for example, by Cook (Ref 2, p 29). The streak camera record was read on a precision comparator which punched out the data directly on IBM cards. A computer code con-... 

Measurements of the transit times of weak shock waves ( 10Q bar) were used to obtain sound wave velocities in larger specimens than listed in Table II. In the arrangement of Fig 3 a cylinder (or slab) of the expl was immersed in a Plexiglas container filled with water. Initiation of the detonator produced a shock wave which arrived nearly plane thru the water at the surface of the expl specimen. The motion of wave was recorded by a smear camera using a shadowgraph technique. Plots of Us up relationships showed that the resulting curves were nearly straight lines and that for particle velocities, up, from 0.3 to 1.2 mm/ftsec, shock wave velocities are ... 

FIGURE 4.9 Observations of the Schlieren effect in everyday life. Source Courtesy of G.S. Settles and reproduced with permission from "Schlieren and shadowgraph techniques" by G.S. Settles, ISBN 978-3-540-661559, Springer (2001), see Ref. [821. 

G.S. Settles, Schlieren and Shadowgraph Techniques, Springer, Weinheim, 2001. 

A phenomenological model for the jet penetration, based on experiments using the shadowgraph technique Extended Wu et al. [1] for spray penetration and width Experimental study focused on surface waves and spray characteristics... 

Shadowgraphs, Mie-scattering, and phase Doppler techniques used to study fuel flux and droplet size distributions. 1 [Pg.681]

As already stated, electroconvection cannot be explained by the standard model for < 0 and Ca < 0. Surprisingly, EC has been observed also for this parameter combination in certain calamitic nematics.These EC patterns differ clearly from the standard EC patterns the rolls are dominantly parallel to the initial director alignment (see Fig. 4.6a). They are not observable using the common shadowgraph technique (single polarizer) but are by using crossed polarizers (plus sometimes an additional... 

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