scholarly journals On the reconstruction of obstacles and of rigid bodies immersed in a viscous incompressible fluid

2017 ◽  
Vol 25 (1) ◽  
pp. 1-21
Author(s):  
Jorge San Martín ◽  
Erica L. Schwindt ◽  
Takéo Takahashi
Keyword(s):  
Incompressible Fluid ◽  
Stokes System ◽  
Partial Information ◽  
Viscous Incompressible Fluid ◽  
Rigid Bodies ◽  
Navier Stokes ◽  
Fluid Structure ◽  
Structure System ◽  
Spherical Waves ◽  
Enclosure Method

AbstractWe consider the geometrical inverse problem consisting in recovering an unknown obstacle in a viscous incompressible fluid by measurements of the Cauchy force on the exterior boundary. We deal with the case where the fluid equations are the nonstationary Stokes system and using the enclosure method, we can recover the convex hull of the obstacle and the distance from a point to the obstacle. With the same method, we can obtain the same result in the case of a linear fluid-structure system composed by a rigid body and a viscous incompressible fluid. We also tackle the corresponding nonlinear systems: the Navier–Stokes system and a fluid-structure system with free boundary. Using complex spherical waves, we obtain some partial information on the distance from a point to the obstacle.

Embeddings for the space on sets of finite perimeter

2019 ◽  
Vol 150 (5) ◽  
pp. 2442-2461 ◽  
Author(s):  
Nikolai V. Chemetov ◽  
Anna L. Mazzucato
Keyword(s):  
Incompressible Fluid ◽  
Viscous Incompressible Fluid ◽  
Rigid Bodies ◽  
Deformation Tensor ◽  
Integrable Deformation ◽  
Sets Of Finite Perimeter ◽  
Open Set ◽  
Finite Perimeter ◽  
Continuous Embedding

AbstractGiven an open set with finite perimeter $\Omega \subset {\open R}^n$, we consider the space $LD_\gamma ^{p}(\Omega )$, $1\les p<\infty $, of functions with pth-integrable deformation tensor on Ω and with pth-integrable trace value on the essential boundary of Ω. We establish the continuous embedding $LD_\gamma ^{p}(\Omega )\subset L^{pN/(N-1)}(\Omega )$. The space $LD_\gamma ^{p}(\Omega )$ and this embedding arise naturally in studying the motion of rigid bodies in a viscous, incompressible fluid.

scholarly journals Self-propelled motion of a rigid body inside a density dependent incompressible fluid

2020 ◽  
Author(s):  
Sarka Necasova ◽  
Mythily Ramaswamy ◽  
Arnab Roy ◽  
Anja Schlomerkemper
Keyword(s):  
Angular Momentum ◽  
Weak Solution ◽  
Global Existence ◽  
Viscous Fluid ◽  
Rigid Body ◽  
Incompressible Fluid ◽  
Stokes System ◽  
Navier Stokes ◽  
Navier Condition ◽  
Whole Space

This paper is devoted to the existence of a weak solution to a system describing a self-propelled motion of a rigid body in a viscous fluid in the whole space. The fluid is modelled by the incompressible nonhomogeneous Navier-Stokes system with a nonnegative density. The motion of the rigid body is described by the  balance of linear and angular momentum. We consider the case where slip is allowed at the fluid-solid interface through Navier condition and prove the global existence of a weak solution.

scholarly journals Stability Analysis of Symmetrical Rotors Partially Filled with a Viscous Incompressible Fluid

2001 ◽  
Vol 7 (5) ◽  
pp. 301-310 ◽  
Author(s):  
Zhu Changsheng
Keyword(s):  
Stability Analysis ◽  
Incompressible Fluid ◽  
Stokes Equations ◽  
Viscous Incompressible Fluid ◽  
Damping Ratio ◽  
Navier Stokes ◽  
Fluid Viscosity ◽  
Navier Stokes Equations ◽  
Rotor Systems ◽  
The Stability

On the basis of the linearized fluid forces acting on the rotor obtained directly by using the two-dimensional Navier-Stokes equations, the stability of symmetrical rotors with a cylindrical chamber partially filled with a viscous incompressible fluid is investigated in this paper. The effects of the parameters of rotor system, such as external damping ratio, fluid fill ratio, Reynolds number and mass ratio, on the unstable regions are analyzed. It is shown that for the stability analysis of fluid filled rotor systems with external damping, the effect of the fluid viscosity on the stability should be considered. When the fluid viscosity is included, the adding external damping will make the system more stable and two unstable regions may exist even if rotors are isotropic in some casIs.

STEADY FLOWS OF A VISCOUS INCOMPRESSIBLE FLUID IN A POROUS HALF-SPACE

1994 ◽  
Vol 04 (05) ◽  
pp. 705-732 ◽  
Author(s):  
ARIANNA PASSERINI
Keyword(s):  
Asymptotic Behavior ◽  
Incompressible Fluid ◽  
Half Space ◽  
Viscous Incompressible Fluid ◽  
Steady Motion ◽  
Navier Stokes ◽  
Asymptotic Behavior Of Solutions ◽  
Steady Flows ◽  
Porous Half Space

In this paper we prove the existence and asymptotic behavior of solutions to the equations describing the steady motion of a viscous incompressible fluid in a porous half-space. The results are compared with those already known for the Navier-Stokes model and we find, in particular, that the behavior at large distances is strongly different depending on the value of the incoming flux through the boundary.

Time delay and Lagrangian approximation for Navier–Stokes flow

Analysis ◽  
2015 ◽  
Vol 35 (4) ◽  
Author(s):  
Nazgul Asanalieva ◽  
Carolin Heutling ◽  
Werner Varnhorn
Keyword(s):  
Fluid Flow ◽  
Time Delay ◽  
Incompressible Fluid ◽  
Stokes Flow ◽  
Stokes Equations ◽  
Viscous Incompressible Fluid ◽  
Navier Stokes ◽  
Incompressible Fluid Flow ◽  
Navier Stokes Equations

AbstractWe consider the nonstationary nonlinear Navier–Stokes equations describing the motion of a viscous incompressible fluid flow for

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