4 research outputs found
Vortical Gusts: Experimental Generation and Interaction with Wing
We describe the experimental generation of isolated vortical gusts and the interaction between these gusts and a downstream airfoil at a Reynolds number of 20,000. A standard method of generating a vortical gust has been to rapidly pitch an airfoil. A different approach is presented here: heaving a plate across a tunnel and changing direction rapidly to release a vortex. This method is motivated by the desire to limit a test article’s exposure to the wake of the gust generator by moving it to the side of the tunnel. Two suites of experiments were performed to characterize the performance of the gust generators and to measure the forces on and flow around the downstream airfoil. The novel mechanism allowed for measurement of the resumption of vortex shedding from the downstream airfoil, which was impossible with the pitching generator
Vortical Gusts: Experimental Generation and Interaction with Wing
We describe the experimental generation of isolated vortical gusts and the interaction between these gusts and a downstream airfoil at a Reynolds number of 20,000. A standard method of generating a vortical gust has been to rapidly pitch an airfoil. A different approach is presented here: heaving a plate across a tunnel and changing direction rapidly to release a vortex. This method is motivated by the desire to limit a test article’s exposure to the wake of the gust generator by moving it to the side of the tunnel. Two suites of experiments were performed to characterize the performance of the gust generators and to measure the forces on and flow around the downstream airfoil. The novel mechanism allowed for measurement of the resumption of vortex shedding from the downstream airfoil, which was impossible with the pitching generator
Isolated Gust Generation for the Investigation of Airfoil-Gust Interaction
As part of an effort to examine the impact of vortical gusts on airfoils, a simple gust
generator has been built and investigated. This consists of a heaving
at plate capable of
following a specifed transverse trajectory across a water tunnel. The relationship between
the trajectory and the properties of the gusts that are shed downstream is characterized
for non-periodic heaving motion described by Eldredge's smooth motion equation. PIV
experiments show that the circulation of the vortical gust is proportional to the heaving
speed of the plate. Tests with a downstream NACA 0018 airfoil demonstrate repeatable
forces in response to the produced gusts