Since the two symmetrical quartz windows utilized for the Schlieren
visualization technique have their limitations as nonvariable position and useful area of visualization, the 14-X B model was positioned to optimize the visualization area for the second ramp and combustion chamber inlet (Figure 7(b)).
Ronney and Wachman (1985) showed that in a [micro]g environment the [S.sub.u] values for lean R-50/air flame measured by the vertical-tube method agreed well with those by the schlieren
method; [S.sub.u] at 5.45 and 5.87 vol% were 4.0 and 6.4 cm/s (1.6 and 2.5 in./s) by the [micro]g vertical-tube method with a 50 mm (2.0 in.) diameter tube and 3.8 and 6.8 cm/s (1.5 and 2.7 in./s) by the [micro]g schlieren
Quality of visualized images depends on the adjusting of schlieren
apparatus, method of correction of unremoved deformations of the optical path of schlieren
system and in case of colour images on the colour component of the image as well.
method is a classical technique that has been limited to small scales.
More sophisticated and sensitive than shadowgraphy, schlieren
imaging has typically required a bright light, a pair of parabolic mirrors--one in front of and the other behind the air disturbance--and a sharp-edged obstacle.
A variation of the schlieren
test, aptly dubbed the rainbow schlieren
because of its colorful appearance, can be used to quantify the peak-to-valley wavefront errors caused by the thermal boundary layer.
Small irregular cavities no larger than 10 cm in diameter formed by the expulsion of volatiles from the magma during crystallization are relatively common throughout the coarse analcime dolerite and are also present in the pegmatite schlieren
. They appear to be genetically related to the larger shrinkage fissures containing the late-stage mineral suite, representing an earlier phase of volatile expulsion.
On the other hand, Schlieren
visualization is used to visualize the shock system.