In order to achieve the project objectives, the wind tunnel will need to be upgraded to create a complex 3D turbulent flow field with cross flow. The cross flow will allow the introduction of a radial component to the flow, which is necessary to simulate real-time conditions in the low-pressure section of a blade cascade. To this end, a secondary bypass channel has been designed, with significant assistance from CFD simulation, to introduce such a cross flow into the wind tunnel test section.
Figure 1. 3D streamlines for the upgraded test section with bypass on at 20m/s main inflow and 20m/s bypass inflow
The position and shape of the bypass injection and suction vents were optimised using CFD simulation (see Figure 1). The modified tunnel test section geometry (see Figure 2) helps to achieve the improved cross flow around the blade surface.
Figure 2. 3D CAD model (top) and 2D schematic (bottom) of the wind tunnel test section with the bypass channel