Schlieren Visualization of a Stratified Flow around a Cylinder

Article type: Research Article

Authors: Chashechkin, Y.D.

Affiliations: Institute for Problems in Mechanics, RAS, prospect Vernadskogo, 101, 117526 Moscow, RUSSIA. E-mail: chakin@ipmnet.ru

Abstract: Description of different modification of schlieren techniques is presented. The methods are based on Maksoutov's scheme of the schlieren mirror instrument with an illuminating slit and a different cutting diaphragm, specifically with Foucault knife, filament or grating. Depending on a slope of the slit to the vertical both black-and-white and colour schlieren images of a stratified flow are produced. Simple colour schlieren method using natural dispersion of white light in a stratified medium is described. 'Natural rainbow' schlieren image of a stratified flow is formed when an illuminated slit is placed horizontally and regular grating is used as a light cutting element. The method is characterised by a high spatial and temporal resolution and by a wider dynamic range than the traditional one. Examples of black-and-white and colour images of a stratified flow near a towing cylinder are presented.

Keywords: colour schlieren technique, stratified flows

Journal: Journal of Visualization, vol. 1, no. 4, pp. 345-354, 1998