Method of determining the optimal coordinate domain in the measurement of water flows turbulence using lad-56 in rectangular channels

Abstract

One of the modern methods of the experimental investigation of water flows turbulence is the method of Laser Doppler Anemometry. At the present time a measuring system “LAD-056” (Russia) is operating in the laboratory of the Department of Hydraulics of MGSU. The authors conducted an analysis of the requirements to experimental data when calculating turbulent characteristics of water flows. The article shows the necessity of checking the database of ripple continuity over time and the required representation of the number of points in the implementation. The results of experiments are presented showing the importance of fixing the length of the implementation and testing time. The authors offered a method of determining the optimal spatial coordinates for the measurement to minimize the time of filling the base of experimental data. According to the methods of defining optimal coordinate domain when measuring turbulent water flows with the use of “LAD-056” in a rectangular channel with glass walls in was established that it is required to conduct measurements within the range from 0 to 120 mm from the closest side wall. In case of greater deepening it is required to use illuminators reducing deflections of laser beams.