Intermittent unsteady propulsion with a combined heaving and pitching foil
Emre Akoz, Amin Mivehchi, Keith W. Moored
Abstract
Aquatic animals swim with a wide range of kinematic motions affecting their shed vortex structures and propulsive performance. We explore the mechanistic trade-offs that occur when caudal fin swimmers use continuous or intermittent combined heaving and pitching motions. It is determined that intermittent swimming can improve efficiency for pitch dominated motions whereas heave dominated motions lead to higher efficiencies with continuous swimming. This phenomenon is a consequence of the physical origins of the force production for heave dominated and pitch dominated motions, which is discussed in light of unsteady thin airfoil theory.
Topics & Concepts
AirfoilMechanicsKinematicsVortexMarine engineeringPropulsionReduced frequencyRange (aeronautics)PhysicsAerodynamicsStrouhal numberFinPropulsorLift (data mining)Lift-to-drag ratioDragGeologyAerospace engineeringEnvironmental scienceVortex sheddingAngle of attackPropulsive efficiencyEngineeringJet propulsionFOIL methodBiomimetic flight and propulsion mechanismsMicro and Nano RoboticsAerospace Engineering and Energy Systems