Circular-to-Rectangular Duct Flows A Benchmark Experimental Study

A comprehensive set of total pressure and three-component laser velocimetry (LV) data has been obtained within two circular-to-rectangular transition ducts at low subsonic speeds. This set of reference data was acquired for use in identifying secondary flow mechanisms and for assessing the accuracy of computational procedures for calculating such flows. Data were obtained at the inlet and exit planes of an aspect ratio three (AR3) duct having a length-to-diameter ratio (L/D) of one (1) and an aspect ratio six (AR6) duct having an L/D of three (3). Each duct was unseparated throughout its transition section. Cross-flow vector plots and contour plots of axial velocity, total pressure, static pressure, axial turbulence, and axial vorticity in the exit plane of each duct are presented.