Dissecting the Flow Physics of Wave-Assisted Propulsion in Single and Multi-Vehicle Systems
Abstract
APPROVED FOR PUBLIC RELEASEThe objective of the proposed research is to gain insights into the hydrodynamics of single and multi-veh,icle wave-assisted propulsion (WAP) systems. A wave-assisted propulsion (WAP) system involves a hydrofoil attached to a surface vehi,cle via linear and/or torsional spring systems. The hydrofoil undergoes a flapping motion that is induced by the surface waves and i,n doing so, generates thrust. A well designed WAP system could enable effective propulsion that uses no (or very little) external po,wer. The performance of a WAP system however depends strongly several parameters and the flow-physics and fluid-structure interactio,n that determines this performance is not well understood. This creates a challenge for understanding and optimizing the performance, of these systems. In the current project, we will dissect the hydrodynamics and associated thrust performance of WAP systems via hi,gh-fidelity computational flow models and new data-enabled analysis tools. A key question that drives our research is: how can we de,sign a WAP system to perform effectively over a wide range of wave conditions, as well as for a variety of platforms.The primary com,putational tool to be employed is ViCar3D, a customized immersed boundary flow solver that has been developed in-house and is well s,uited for direct and large-eddy simulation of such flows. The analysis will rely heavily on the force (FPM)and power partitioning me,thods (PPM); methods that have been developed recently by the PI. These data-enabled methods provide unprecedented insights into the, fundamental mechanisms for pressure force generation in vortex dominated flows. The aims of the project will be achieved via the fo,llowing four research thrusts:(1) Modeling and analysis of a single submerged WAP foil, including FSI modeling and analysis for mono,chromatic and irregular waves.(2) Detailed analysis of foil-foil interaction and determination of hydrodynamic mechanisms that could, be exploited in multi-foil and multi-vehicle WAP systems.(3) Investigation of the interaction of WAP foils with the free surface fo,r foils operating at shallow depth, and identification of interaction mechanisms that can improve performance.(4) Investigation of t,he combined effects of foil-foil and wave-foil interactions including the development of guidelines for a multi-vehicle WAP system t,hat can exploit these interactions for effective harnessing of waves for thrust augmentation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 06, 2022
- Source ID
- N000142212770
Entities
People
- Rajat Mittal
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy