Effect of applying screen and honeycomb to the flow characteristic in wind tunnel based on CFD simulation

Abstract

In the field of wind tunnel testing, flow quality is one of considerations which determine the accuracy of data measurement. There are several aspects that affect the flow quality, such as blade design, flow conditioner application and tunnel circuit configuration (i.e. design of the corner vane, corner duct, contraction duct and etc.). Applying flow conditioner like screen or mesh and honeycomb is commonly used to improve the flow quality in the tunnel. This paper discusses about the effect of applying screen and honeycomb to the flow characteristic in a simple tunnel model. The screen was applied on the several locations at the WAD (wide angle diffuser), i.e. at the inlet, middle section, and at the outlet of the WAD. Honeycomb was applied after the last screen in the tunnel duct. In the modelization, the applied screen or mesh and honeycomb were modeled using porous media computational model and using Darcy law as a mathematical model. The CFD simulation was performed using Numeca by separating the domain into fluid domain section (for the tunnel section) and porous media domain (for the screen and honeycomb section). Unstructured mesh type, generated by Hexpress, was used on the tunnel computational domain. The results indicate the reduction of flow separation, hence more uniform flow in the tunnel, by applying screen or mesh at the WAD and by applying honeycomb in the chamber.