Experimental study of the flow turbulent structure in a cell of a lattice matrix.

The experimental results on the turbulent flow structure in a lattice matrix cell, which is a region between intersecting ribs on the opposite walls of a flat channel, are presented. The angle between the ribs was 2β = 60°, 90° and 120°; the Reynolds number calculated from the average velocity and hydraulic diameter of the channel was varied in the range Re = (1–7)·10⁴. The aerodynamic characteristics of the flow inside a lattice matrix cell placed in a rectangular channel with a cross section of 20×150 mm and a length of 400 mm were measured using a two-component laser Doppler anemometer (LDA). The flow structure was studied in individual cells of 15×15 mm, formed by crossing ribs on the opposite channel walls. The complex three-dimensional structure of the flow in the matrix cells and strong turbulence of the flow in the near-wall regions are shown. The installation of ribs leads to a significant increase in hydraulic losses, especially at large crossing angles. [ABSTRACT FROM AUTHOR]