The test problem in question is a turbulent flow over a 90o bend. The schematic view of
the experimental setup comprising of an open-circuit suction wind tunnel system for the
90o duct bend is shown in the figure below. It comprises of a 3.5 m long horizontal duct,
a 90o bend with a radius ratio of 1.5 and a 1.8 m long vertical straight duct. Air flows
through a 10 mm thick Perspex square test section with the bulk gas velocity Ub adjusted
through the aid of a variable frequency controller. Experimental data are obtained on this
experimental setup using flow visualization and Laser Doppler Anemometry (LDA)
system