CFD Results CD Drag Coefficient The drag coefficient

CFD Results CD – Drag Coefficient The drag coefficient is a dimensionless parameter that characterizes an object’s resistance to fluid flow and allows for direct comparison of aerodynamic effects on different shapes. Some examples of drag coefficients are the Empire State Building (1. 3 -1. 5) and the Eiffel Tower (1. 8 -2. 0). The Eiffel tower suffers from more drag overall which means that, for a given airflow condition, the Eiffel tower will be subjected to a larger drag force than the Empire State Building. Velocity Profile and Pressure Distribution of scale arborloo exposed to 95 mph winds Load Cell and Pressure Scanner Setup Velocity Profile and Pressure Distribution of full size arborloo exposed to 95 mph winds Testing has provided a variety of results. The most current results do not match predicted values of Drag Coefficient. The team has found a c. D of approximately 2. 0, while the expected c 0 should be in the range of 1. 2. The team believes the walls of the wind tunnel are affecting measured wind speed. This is not uncommon as boundary layer effects and blockage effects are weaknesses of wind tunnel testing. Correction factors will be found by using CFD software. Our final design for the test stand utilizes the existing equipment of the KGCOE wind tunnel. We created a metal flange that will bolt onto the circular hole in the middle of the base plate. This flange rests in the base plate of the wind tunnel, and has a hole through which the load cell shaft is placed. The load cell shaft is used to support the load cell and the arborloo model. This shaft can be adjusted up and down according to the size of the model to be tested. A collar with a set screw is welded to the bottom of the flange, and will be used to lock the load cell shaft in place. The model arborloo has an array of evenly spaced pressure taps