A - a view in the invisible

Abstract

Flow visualization is an important topic in, experimental and computational fluid dynamics and has been the subject of research for many years. This paper presents an overview of flow visualization techniques. The physical basis and applications of different visualization methods for subsonic, transonic and supersonic flow in wind and water tunnels are described: direct injection methods, (smoke, dye, fog and different small particles), gas and hydrogen bubbles, , flow visualization by tufts, oil, liquid crystals, pressure and temperature sensitive paints, shadow, schlieren, interferometry, Laser Doppler Anemometry, Particle Image Velocimetry and other special techniques. Almost all presented photos have been recorded during tests in laboratories of MTI Belgrade.

Special Cases of Using Visualization Technology for Analyzing the Dynamics of Gaseous Environment

“…The work [4] can be cited as an example of the study of these issues based on a thorough reconstruction of a virtual picture of gas dynamics processes. The interaction of numerical and experimental visualization for practical use has been considered in many investigations [5][6][7][8][9][10][11]. An example of the technical use of visualization of gas detonation in channels for verification of computational models of processes can be found in the research [12].…”

Experimental and numerical study of super-critical flow around the rough sphere

“…In the VTI wind tunnels the sphere is included in various experiments, both for the pressure and force measurements, the flow quality, as well the imaging by the optical and nonoptical techniques. The purpose of the non-optical flow T visualizations, in this work given around the sphere, is a verification of the experimental data measurement while, described by Ristic [19][20][21][22]; the optical visualization techniques are able to determine quantitative values of the flow parameters either of the flow around the sphere or in the complex flow, such is in the axial fan [23].…”