1 Why wingtips matter

The main function of wingtips is to reduce the induced drag that is caused by the pressure difference between the upper and lower surfaces of the wing. This pressure difference creates a vortex at the wingtip, which generates a downward force on the wing and reduces its lift. The stronger the vortex, the higher the induced drag and the lower the aerodynamic efficiency. Wingtips can reduce the strength of the vortex by changing the shape, size, or angle of the wing's edge.

2 Types of wingtip devices

There are several types of wingtip devices that can improve the aerodynamic performance of an aircraft, such as winglets, raked wingtips, blended winglets, sharklets, and spiroids. Winglets are vertical or angled extensions of the wingtip that reduce the vortex strength and increase the wingspan and aspect ratio. Raked wingtips are swept back at a higher angle than the rest of the wing and have less drag than winglets. Blended winglets smoothly transition from the wing to the vertical tip and provide lower drag and noise than conventional winglets. Sharklets have a curved shape that resembles a shark's fin and are lighter and more aerodynamic. Spiroids wrap around the wingtip and create a continuous surface which can reduce drag and fuel consumption significantly, but they are not widely used due to their complexity and cost.

3 How to optimize wingtip shape

The optimal wingtip shape for an aircraft depends on several factors, such as its size, weight, speed, range, and mission. However, when selecting the best wingtip device, you should consider the trade-off between drag reduction and weight increase. Wingtip devices can lower the drag of the aircraft but they also add weight and structural complexity. Additionally, you should consider the operating altitude and speed, as well as the wing geometry and design. Wingtip devices are more effective at higher altitudes and speeds, where the induced drag is higher and the vortex is stronger. Furthermore, they can affect the aerodynamics of the whole wing, not just the tip. Therefore, you need to consider the shape, size, and sweep of the wing and how it interacts with the wingtip device. For example, a wing with a high sweep angle may benefit more from a raked wingtip than a winglet since it can increase the effective sweep and reduce wave drag.

4 How to test wingtip shape

The best way to test the performance of different wingtip shapes is to use a combination of computational and experimental methods. Computational methods, such as computational fluid dynamics (CFD), can simulate the airflow around the wing and the wingtip device and calculate the drag and lift coefficients. Experimental methods, such as wind tunnel testing and flight testing, can validate the computational results and measure the actual effects of the wingtip device on the aircraft. By comparing the results of both methods, you can evaluate the effectiveness and feasibility of different wingtip shapes.

5 How to implement wingtip shape

The final step of optimizing the wingtip shape is to implement it on the aircraft. Depending on the type of wingtip device, you may need to modify the existing wing structure or add a new component. You may also need to adjust the flight controls, the stability systems, and the performance parameters of the aircraft to account for the changes in the aerodynamics. You should also monitor the performance and fuel consumption of the aircraft after implementing the wingtip device and compare it with the baseline data.