Perforated-sheet disintegration

In perforated-sheet disintegration shown in Figure 16.19b, small holes suddenly appear in the sheet as it advances into the atmosphere. They rapidly grow in size(36) until the thickening rims of adjacent holes coalesce to form threads of varying diameter. The threads finally break down into drops. 

The disintegration of liquid sheets as studied by many authors [40-42] is generally a two-step process. First, liquid threads and/or ligaments disintegrate from the sheet, which secondly break into droplets due to capillary instabilities. This can be induced either through perforations or destabilising waves in the liquid sheet [40]. 

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