BACKGROUND

Vortex generators are a common aerodynamic device used to delay flow separation. On aircraft, flow separation can cause non-optimal flight conditions when a lifting surface is operating at low speeds associated with takeoff and approach to landing. Vortex generators improve safety and efficiency of such low-speed flight by re-energizing flow over the lifting surface and preventing stall until high angles of attack. However, at cruising speeds, vortex generators cause drag and can negatively affect efficiency. Deployable vortex generators are a promising option, but current deployment systems require remote control systems, electrical power, and/or expensive materials. A simple and reliable system for deploying vortex generators only when needed is desirable.

SUMMARY

The present disclosure provides systems, apparatuses, and methods relating to passive deployment of a vortex generator. In some examples, a system for passive deployment of a vortex generator may include a housing mounted at a fixed location relative to an airfoil structure and a piston contained in the housing. A vortex generator may be moveably mounted adjacent an exterior surface of the airfoil structure, and may be moveable between a stowed position inside the airfoil structure and a deployed position outside the airfoil structure. The piston may be configured to drive the vortex generator between the stowed position and the deployed position in response to a pressure differential between a first airstream over a first surface of the airfoil structure and a second airstream over a second surface of the airfoil structure.

In some examples, an aircraft may include an airfoil structure connected to a fuselage. A housing may be mounted at a fixed location relative to the airfoil structure, with a piston contained in the housing. The aircraft may further include a vortex generator moveably mounted adjacent an exterior surface of the airfoil structure, and moveable between a stowed position inside the airfoil structure and a deployed position outside the airfoil structure. The piston may be configured to drive the vortex generator between the stowed position and the deployed position in response to a pressure differential between a first airstream over a first surface of the airfoil structure and a second airstream over a second surface of the airfoil structure.

In some examples, a method of deploying a vortex generator may include sending a pressure differential between a first airstream over a first surface of an airfoil structure and a second airstream over a second surface of the airfoil structure. The method may further include passively moving a vortex generator from a stowed position to a deployed position in the first airstream, in response to sending a selected first threshold value of the pressure differential.

Features, functions, and advantages may be achieved independently in various examples of the present disclosure, or may be combined in yet other examples, further details of which can be seen with reference to the following description and drawings.

