Details

Autor(en) / Beteiligte

• Nangia, Nishant
• Johansen, Hans
• Patankar, Neelesh A.
• Bhalla, Amneet Pal Singh

Titel

A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies

Ist Teil von

• Journal of computational physics, 2017-10, Vol.347 (C), p.437-462

Ort / Verlag

Cambridge: Elsevier Inc

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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 far-field (smooth) velocity and pressure information is used. We re-visit 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. •Simple and efficient approach to compute hydrodynamic force/torque on moving bodies.•Hydrodynamic stress tensor is evaluated on an accelerating box.•Spurious force oscillations in drag/torque coefficients are suppressed.•Proposed method works for direct forcing and fully constrained IB methods.