Correlation analysis for the research of local characteristics of a turbulent flow

Abstract

The paper describes the temperature-correlation velocimetry technique applied to the flow of water or liquid metal. The method allows simultaneous measurement of temperature signals and local values of a longitudinal velocity component in the flow. This approach is a simple and reliable method for measuring velocity in flows of optically impermeable fluids. At the same flow conditions, different coolants have different spatial-temporal characteristics that are processed using a temperature-correlation technique. This work is devoted to the development of an algorithm for formulating a set of practical recommendations for the use of this technique to measure velocity and to determine a metrological characteristic in various conditions. For calibration, water and mercury are used as model liquids. The data obtained are presented in the form of fields of temperature and intensity of temperature fluctuations. Autocorrelation and cross-correlation functions are compared for two investigated liquids under the same conditions.