Hybrid Multi-Resolution and Multi-Fidelity Simulation of Bubbly Flows in Ship Wakes

Abstract

We propose to develop a novel computational framework and use it to simulate and model the bubbly flows in ship wakes. It will have, multi-resolution to accurately and efficiently account for the hydrodynamic processes ranging from the ship and wake scales to bubb,le scales. It will also use multi-fidelity simulations by combining the unsteady Reynolds-averaged Navier-Stokes simulation and lar,ge-eddy simulation, while incorporating bubble models developed by collaborators based on direct numerical simulation and experiment, studies. The proposed computational framework will contain a two-phase flow solver combined with an immersed boundary method to ad,dress the interactions among bubbles, water, ship hull and appendages. To further enhance the computational power, we will incorpor,ate adaptive mesh refinement to reduce the computational cost and memory requirement. The objectives of the proposed project are: ,Develop a computational framework for the bubbly flow in ship hydrodynamics to establish a simulation capability to connect the basi,c research on bubble dynamics and modeling to the ship wake applications. Use our simulations as a useful tool for the assessment,, improvement, and validation of the models for bubble generation, fragmentation, and coalescence, for example the models developed b,y the collaborators in the ONR bubbly wake program.Help the data analysis of experiment work conducted in the ONR bubbly wake progr,am. Investigate the mechanisms underlying bubble generation, transport, fragmentation, coalescence, and extinction. Understand a,nd quantify their dependence on the hydrodynamic processes and operation conditions of surface ships. Develop the next generation o,f physics-based bubble models that can be readily employed by the Navys researchers for applications. The proposed research task,s include:Research Task 1: Develop a multi-fidelity computational framework for ship bubbly flows. We will develop an advanced imm,ersed boundarymethod for ship hull and appendage geometries together with an innovative adaptive mesh refinement technique for multi,-resolution simulation, based on which hybrid LES/URANS modeling will be developed.Research Task 2: Develop a multi-scale modeling,method for ship bubbly flows, which consists of grid-scale simulation of free-surface flows and subgrid-scale bubble modeling.Resea,rch Task 3: Investigate bubbly wake hydrodynamics. We will also collaborate with other investigators in the ONR bubbly flow program, by helping assess the performance of DNS-based bubble entrainment model in our ship-scale simulations and providing assistance to t,he interpretation of experiment data of bubbly flows. Based on the flow mechanisms revealed, we will develop improved models of bub,bly wake flows.Based on the research of this project, the next generation of physics-based bubble models can be developed to be empl,oyed by the Navys researchers for defense applications. This summary is approved for public release.

Document Details

Document Type
DoD Grant Award
Publication Date
Jul 08, 2022
Source ID
N000142212481

Entities

People

  • Lian Shen

Organizations

  • Office of Naval Research
  • Regents of the University of Minnesota
  • United States Navy

Tags

Readers

  • Computational Fluid Dynamics (CFD)