A computational framework for flow-induced vibrations of propeller blades in cavitating flows
department or school: Applied Science, Faculty of
department or school: Mechanical Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Darbhamulla, Nihar Bhardwaj
issued: 2024-05-03T21:51:49Z
issued: 2024
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: In the current work, we present a finite-element computational framework for Fluid-Structure Interaction problems subjected to the coupling of unsteady cavitating flows with flexible structures. We build upon a previously developed stabilized variational framework for multiphase FSI by incorporating a dynamical structural solver based on the modal decomposition of the structure. In the first part of the work, we present the validation of the current framework for conducting Large Eddy Simulations (LES) of cavitating flows past rigid structures. We identify the resolution criteria for dynamic subgrid-scale LES based on the re-entrant jet momentum - a prominent phe- nomenon associated with cavity-shedding in the wake of immersed bodies. The validated framework is then used to elucidate the features of cavitating flow past a rigid hydrofoil. In particular, we iden- tify features of sheet-cavitating flow which enable the transition to cloud cavitation. Further, we evaluate the instabilities driving sheet-cavity breakdown and establish the vortical structures which drive cloud cavity collapse, and quantify the frequencies observed over the course of a cavitation cycle. In the second part of the work, we present the validation of the framework for LES of cavitating flows past flexible structures. Based on the validation study conducted over a flexible NACA66 rectangular hydrofoil, we elucidate the role of cavity and vortex shedding in the structural dynamics at three different cavitation numbers. We identify a broad spectrum frequency band whose central peak does not correlate to the frequency content of the cavitation dynamics or the natural fre- quencies of the structure, indicating the induction of unsteady flow patterns around the hydrofoil. Finally, we discuss the coupled fluid-structure dynamics during a cavitation cycle associated with the promotion and mitigation of cavitation.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88213
note: A Computational Framework forFlow-Induced Vibrations of PropellerBlades in Cavitating FlowsbyNihar Bhardwaj DarbhamullaB.Tech., Indian Institute of Technology Guwahati, 2019A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFMASTER OF APPLIED SCIENCEinThe Faculty of Graduate and Postdoctoral Studies(Mechanical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)April 2024© Nihar Bhardwaj Darbhamulla 2024The following individuals certify that they have read, and recommend to the Faculty of Graduateand Postdoctoral Studies for acceptance, the thesis entitled:A Computational Framework for Flow-Induced Vibrations of Propeller Blades in Cav-itating Flowssubmitted by Nihar Bhardwaj Darbhamulla in partial fulfillment of the requirements for thedegree of Master of Applied Science in Mechanical EngineeringExamining Committee:Dr. Rajeev Jaiman, Associate Professor, Department of Mechanical Engineering, UBCSupervisorDr. Carl Ollivier-Gooch, Professor, Department of Mechanical Engineering, UBCSupervisory Committee MemberDr. Anthony Wachs, Professor, Department of Chemical and Biological Engineering, UBCSupervisory Committee MemberiiAbstractIn the current work, we present a finite-element computational framework for Fluid-StructureInteraction problems subjected to the coupling of unsteady cavitating flows with flexible structures.We build upon a previously developed stabilized variational framework for multiphase FSI byincorporating a dynamical structural solver based on the modal decomposition of the structure.In the first part of the work, we present the validation of the current framework for conductingLarge Eddy Simulations (LES) of cavitating flows past rigid structures. We identify the resolutioncriteria for dynamic subgrid-scale LES based on the re-entrant jet momentum - a prominent phe-nomenon associated with cavity-shedding in the wake of immersed bodies. The validated frameworkis then used to elucidate the features of cavitating flow past…
has type: Thesis/Dissertation
date issued: 2024-05
is shown at: 10.14288/1.0442260
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Jaiman, Rajeev
type: Text
identifier URI: http://hdl.handle.net/2429/88213