Accession Number:

AD1085920

Title:

Fluid-Structure Interactions Employing Cyber-Physical Fluid Dynamics

Descriptive Note:

Technical Report,15 Jun 2015,14 Dec 2018

Corporate Author:

Cornell University Ithaca United States

Personal Author(s):

• Williamson,Charles H.

Report Date:

2019-04-24

Pagination or Media Count:

115.0

Abstract:

In this research, we implement a novel type of experimental apparatus for unsteady aerodynamics, which we call the Cyber Physical Fluid Dynamics CPFD Facility. Unlike traditional fluid mechanics experiments, CPFD is a general purpose technique that allows one to impose arbitrary forces on an object submerged in a fluid. We examine how the propulsive performance of an oscillating airfoil is improved by the addition of passive dynamics in this case using active heave and passive pitch. The passive pitching allows the airfoil to produce up to an order of magnitude more thrust as compared to heave alone. In a further study, we are interested in self propulsion of a heaving and pitching airfoil. We employ a force feedback technique to simulate true self propulsion. The pitch plays a crucial role in controlling the instantaneous angle of attack. In fact, the most efficient operating point is one where the angle of attack is as high as possible, but just prior to airfoil stall. Reducing or removing flow separation and the formation of a leading edge vortex LEV corresponds to maximum efficiency and a maximum performance of the airfoil as a propulsor.

Descriptors:

• strouhal number
• flow separation
• energy
• leading edges
• fluid dynamics
• reynolds number
• environmental monitoring
• pressure distribution
• search and rescue
• actuators
• efficiency
• feedback
• self propelled
• underwater vehicles
• vortex shedding
• vortices
• energy storage
• fluid flow

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE