Design and Setup of Z-Type Schlieren Imaging System for Flow Visualization

Abstract

Amid the research works in the field of aerodynamics and flow physics, visual experiments become a key aspect to understand the physics behind the phenomenon at work. Owing to the sensitivity of phenomenon involved in those fields, non-intrusive techniques hold greater preference over intrusive techniques. Schlieren photography is one such example of non-intrusive technique, used for the qualitative and quantitative analysis of different fluid-flow phenomena involving density gradients. In this study, a portable experimental setup of the z-type schlieren technique sitting in a bench-top of size 90 cm × 90 cm, consisting of two reflecting telescope parabolic mirrors of 76 mm diameter and 400 mm focal length is fabricated. With this setup, the qualitative and quantitative analysis of different fluid flow phenomena was performed. Negatively-Buoyant Plumes in water and Under-expanded jet from a converging-diverging nozzle are the flow-phenomena visualized. The visualized phenomena range from subsonic characteristic to supersonic characteristic. The cold dense water forming in the lower surface of the floating ice cascading into the less dense lukewarm water was considered as the experimental case for the study of Negatively-Buoyant Plumes.