A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies
Here, we present a moving control volume (CV) approach to computing hydrodynamic forces and torques on complex geometries. The method requires surface and volumetric integrals over a simple and regular Cartesian box that moves with an arbitrary velocity to enclose the body at all times. The moving box is aligned with Cartesian grid faces, which makes the integral evaluation straightforward in an immersed boundary (IB) framework. Discontinuous and noisy derivatives of velocity and pressure at the fluid–structure interface are avoided and farfield (smooth) velo city and pressure information is used. We revisit the approach to compute hydrodynamic forces and torques through force/torque balance equations in a Lagrangian frame that some of us took in a prior work (Bhalla et al., 2013 [13]). We prove the equivalence of the two approaches for IB methods, thanks to the use of Peskin's delta functions. Both approaches are able to suppress spurious force oscillations and are in excellent agreement, as expected theoretically. Test cases ranging from Stokes to high Reynolds number regimes are considered. We discuss regridding issues for the moving CV method in an adaptive mesh refinement (AMR) context. The proposed moving CV method is not limited to a specific IB method andmore »
 Authors:

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 Northwestern Univ., Evanston, IL (United States). Dept. of Engineering Sciences and Applied Mathematics
 Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Applied Numerical Algorithms Group
 Northwestern Univ., Evanston, IL (United States). Dept. of Engineering Sciences and Applied Mathematics, Dept. of Mechanical Engineering
 Publication Date:
 Grant/Contract Number:
 AC0205CH11231; SI2SSI1450374; DGE1324585; NIH HL117163; ACI 1450327
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Computational Physics
 Additional Journal Information:
 Journal Volume: 347; Journal Issue: C; Journal ID: ISSN 00219991
 Publisher:
 Elsevier
 Research Org:
 Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC21); National Science Foundation (NSF); National Institutes of Health (NIH)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 97 MATHEMATICS AND COMPUTING; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; immersed boundary method; spurious force oscillations; reynolds transport theorem; adaptive mesh refinement; fictitious domain method; lagrange multipliers
 OSTI Identifier:
 1379929
Nangia, Nishant, Johansen, Hans, Patankar, Neelesh A., and Bhalla, Amneet Pal Singh. A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies. United States: N. p.,
Web. doi:10.1016/j.jcp.2017.06.047.
Nangia, Nishant, Johansen, Hans, Patankar, Neelesh A., & Bhalla, Amneet Pal Singh. A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies. United States. doi:10.1016/j.jcp.2017.06.047.
Nangia, Nishant, Johansen, Hans, Patankar, Neelesh A., and Bhalla, Amneet Pal Singh. 2017.
"A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies". United States.
doi:10.1016/j.jcp.2017.06.047. https://www.osti.gov/servlets/purl/1379929.
@article{osti_1379929,
title = {A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies},
author = {Nangia, Nishant and Johansen, Hans and Patankar, Neelesh A. and Bhalla, Amneet Pal Singh},
abstractNote = {Here, we present a moving control volume (CV) approach to computing hydrodynamic forces and torques on complex geometries. The method requires surface and volumetric integrals over a simple and regular Cartesian box that moves with an arbitrary velocity to enclose the body at all times. The moving box is aligned with Cartesian grid faces, which makes the integral evaluation straightforward in an immersed boundary (IB) framework. Discontinuous and noisy derivatives of velocity and pressure at the fluid–structure interface are avoided and farfield (smooth) velo city and pressure information is used. We revisit the approach to compute hydrodynamic forces and torques through force/torque balance equations in a Lagrangian frame that some of us took in a prior work (Bhalla et al., 2013 [13]). We prove the equivalence of the two approaches for IB methods, thanks to the use of Peskin's delta functions. Both approaches are able to suppress spurious force oscillations and are in excellent agreement, as expected theoretically. Test cases ranging from Stokes to high Reynolds number regimes are considered. We discuss regridding issues for the moving CV method in an adaptive mesh refinement (AMR) context. The proposed moving CV method is not limited to a specific IB method and can also be used, for example, with embedded boundary methods.},
doi = {10.1016/j.jcp.2017.06.047},
journal = {Journal of Computational Physics},
number = C,
volume = 347,
place = {United States},
year = {2017},
month = {10}
}