Journal of Water Security, Volume 1 (2015)

Structures of turbulent vortices and their influence on flow properties

Alfonsas Rimkus
Aleksandras Stulginskis University

Abstract

In spite of many investigations performed on turbulent flows, the generation and the development of turbulent vortices was investigated insufficiently yet. It prevents to understand well the processes going in the flow, what is unfavorable for their further investigations. The developing vortex structures interact between them, and it needs to be estimated. Physical summing of velocities, formed by all structures, can be unfavorable for investigations, therefore they must be separated; otherwise the bias errors can occur. Difficulty for investigations is that the widely employed Particle Image Velocity (PIV) method, when a detailed picture of velocity field is necessary, can provide photos covering only a short interval of flow, which can’t include the largest structures of flow, i.e. the macro whirlpools. Consequently action of these structures could not be investigated. Therefore in this study it is tried to obtain the necessary data about the flow structure by analyzing of instantaneous velocity measurements by 3D means, which continues several minutes, therefore the existence and interaction of these structures become visible in measurement data. The investigations performed in this way have been already discussed in the article, published  earlier. Mostly it was analyzed the generation and development of bottom vortices. In this article, it is continued the analysis of these turbulent velocity measurements and the additional data about the structure of turbulent vortices is obtained.

Keyword(s): hydraulic investigations, structure of turbulent vortices, measurement analysis


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DOI: http://dx.doi.org/10.15544/jws.2015.002

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