Experimental Set-Up for 2D Cargo Release Test in Subsonic Wind Tunnel

Abstract

The objective of this research is to design a 2D inexpensive mechanism for testing the cargo separation in a wind tunnel. Our designed mechanism simulates the separation of a NACA-0012 airfoil from the upper wall of a wind tunnel. To perform the test, we have used a low-speed (0–100 m/s) wind tunnel with a $160\times 80\times 100$ cm test chamber. First, 2 electromagnets fix the model in its initial position so that the wind tunnel reaches the required speed. Then, the power is cut off, the model releases and the test begins. Finally, the movements are stopped by the spring and other limiters, and the test finishes. The process is filmed during the test by special cameras and, using image processing. The x, y, and $\theta$ diagrams with respect to the time are presented as the test results. There are also two accelerometers which are installed on the mechanism along x and y directions; they store acceleration with respect to the time and make it possible to calculate the velocity and position of the body at any moment. Such limitations as costs, availability in the market, aerodynamic, and structure were also studied during the design process. To create 2D aerodynamic conditions, 2 circular plates were fixed at the beginning and end of the wing. To provide appropriate structural strength (safety factor of 2), the diameter of the horizontal and vertical steel rails are considered 1 and 2 cm, respectively.