# Mini Glider Design and Implementation with Wing-Folding Mechanism
## 3 Simulation and Analysis
The AoA at the point where \(\alpha=-3^{\circ}\) is taken since it gives the maximum ratio of L/D. Aerodynamic coefficients match in both theoretical and simulation results. This is followed by the wing folding mechanism during separation of the glider from the container. Most folding theories are concerned with either speed of a stowed mechanism or its effect on the lift force. However, the strength of the wings and the folding mechanism should not be neglected. Deployment of the glider needs just a simple action from the user, since basic components are used, which are springs and magnets that are shown in Figure 7. In this figure, wing slots and magnets are represented in isometric view and springs can be seen in the top view of the glider. In our first configuration, only a spring is used in the wing folding mechanism. Figure 5: According to the Vortice Lattice Method (VLM), an analysis is done in the XFLR5® program. Accordingly, more \(C_{L}\) and lower \(C_{D}\) are calculated. The pressure points, which are more likely to be at the leading edge and less towards the tail, are shown by the right legend. In addition, axial and Euler parameters are represented on the glider. Figure 6: The \(L/D-\alpha\) graph, which represents Gaussian curve, is acquired based on the 3D simulation that is given in Figure 5. AoA distribution only takes the maximum value at a certain angle interval. Therefore, in the remaining region except about \(\alpha=-3^{\circ}\), there are exponential curve characteristics. Folding mechanism and glider sizes are affected by the miniaturization of core technologies. However, the endurance of miniature drones' wings are questionable when they are exposed to maximum force [7; 8; 9]. The aim is to show that the wings are completely foldable even in unsuitable conditions. First, only a spring is used in the wing folding mechanism. This allows the mechanism to store potential energy. It would be desirable for the wing to be deployed parallel to the normal line, but the energy stored in the spring mechanism is designed to move the wing \(8^{\circ}\) forwards in 114 ms in Figure 8. However, after this movement of the wing, the wing moves back and falls short of the parallel wing position by \(19^{\circ}\) in 157 ms in an oscillating manner. When only a spring is used, it shows that the energy stored in the springs during the folding of the wings can not absorb the potential energy efficiently. For this reason, it was observed that the folding response of the wings has oscillations during their deployment and it is reported with the duration and angle. The recoil of \(19^{\circ}\) has to be damped with additional equipment on the glider. To find the damping force needed, spring coefficient, k, should be determined first to evaluate repulsive force. K can be obtained experimentally by measuring ten fixed different weights whose mass are determined with three decimal precision scales with 1 mg resolution. Experimental results of k are detailed in Section 4. After that, neodymium magnets are used as a damping element and detailed in Section 4 in the second configuration. All equipment is designed to be used to simulate flight trajectory in MATLAB SIMULINK(r) by using equations that are mentioned in the mathematical modeling section. After finding all the necessary parameters and calculation results, the glider's components' mass can be expressed in Table 4.  
Figure 8: Left: picture of glider in folded position; middle: picture of the first deployed position exceedance with \(8^{\circ}\) in 114 ms; right: picture of first recoil, falling short with \(19^{\circ}\) in 157 ms.  
Figure 5.0 Left: the picture of the model shows magnets and dimensions and their positions on the wing slots; right: the picture of the folding mechanism including springs and rotational axis. The system model could be done by designing the equipment the same as the results, including their mass. Glider force and moment stability could be achieved during 12 (m/s) flight speed and \(\alpha=-3^{\circ}\).