Fluid/Structure Interaction Modeling of Helicopters Using the Navier-Stokes Equations

2012 ◽  
Author(s):  
Guru Guruswamy
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Modeling

Review on Fluid Structure Interaction Solution Method for Biomechanical Application

2014 ◽  
Vol 660 ◽  
pp. 927-931 ◽  
Author(s):  
Nazri Huzaimi bin Zakaria ◽  
Mohd Zamani Ngali ◽  
Ahmad Rivai
Keyword(s):  
Stokes Equations ◽  
Complex Geometry ◽  
Fluid Structure Interaction ◽  
Navier Stokes ◽  
Structural Parameter ◽  
Clear Understanding ◽  
Arbitrary Lagrangian Eulerian ◽  
Navier Stokes Equations ◽  
Fluid Structure ◽  
Structure Interaction

Fluid-Structure Interaction engages with complex geometry especially in biomechanical problem. In order to solve critical case studies such as cardiovascular diseases, we need the structure to be flexible and interact with the surrounding fluids. Thus, to simulate such systems, we have to consider both fluid and structure two-way interactions. An extra attention is needed to develop FSI algorithm in biomechanic problem, namely the algorithm to solve the governing equations, the coupling between the fluid and structural parameter and finally the algorithm for solving the grid connectivity. In this article, we will review essential works that have been done in FSI for biomechanic. Works on Navier–Stokes equations as the basis of the fluid solver and the equation of motion together with the finite element methods for the structure solver are thoroughly discussed. Important issues on the interface between structure and fluid solvers, discretised via Arbitrary Lagrangian–Eulerian grid are also pointed out. The aim is to provide a crystal clear understanding on how to develop an efficient algorithm to solve biomechanical Fluid-Structure Interaction problems in a matrix based programming platform.

A Fluid-Structure Interaction Modeling Approach of Lubricated Bearing-Type Sliding Contacts

2012 ◽  
Author(s):  
Jeremiah N. Mpagazehe ◽  
C. Fred Higgs
Keyword(s):  
Reynolds Equation ◽  
Moving Boundary ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Navier Stokes ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Processing Power ◽  
Interaction Modeling

In many tribological applications, such as journal bearings and gears, a fluid film is used to accommodate velocity between moving surfaces. To model the behavior of this film and to predict its ability to carry load, the Reynolds equation is predominantly employed. As computational processing power continues to increase, computational fluid dynamics (CFD) is increasingly being employed to predict the fluid behavior in lubrication environments. Using CFD is advantageous in that it can provide a more general approximation to the Navier-Stokes equations than the Reynolds equation. Moreover, using CFD allows for the simulation of multiphase flows as could occur during bearing contamination and bearing exit conditions. Because the bearing surfaces move relative to each other as they obtain equilibrium with the fluid pressure, there is a need to incorporate the moving boundary into the CFD calculation, which is a non-trivial task. In this work, a fluid-structure interaction (FSI) technique is explored as an approach to model the dynamic coupling between the moving bearing surfaces and the lubricant. The benefits of using an FSI approach are discussed and the results of its implementation in a lubricated sliding contact model are presented.

scholarly journals Bottom rack intake improvement as a fluid physics application through a computational fluid dynamics model

2021 ◽  
Vol 2118 (1) ◽  
pp. 012003
Author(s):  
H E Calderón ◽  
L M Rada ◽  
J S De Plaza
Keyword(s):  
Stokes Equations ◽  
Flow Behavior ◽  
Fluid Structure Interaction ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Physics ◽  
Starting Point ◽  
Surrounding Areas

Abstract This research focuses on improving the hydraulic behavior of a traditionally design bottom rack intake, from variations in roughness parameters, free height, and the inclusion of chamfers, establishing a contribution to the contrast between classical physics and the physics that takes over the partial resolution of the Navier-Stokes equations. To make possible the structure in OpenFOAM, it is necessary to use the geometric tool Salome-Meca, as well as a meshing tool (snappyHexMesh), and the InterFOAM solver in the processing stage. In the same way, through the turbulence model (K-E) local effects are evidenced in the Fluid-Structure interaction, as well as the identification of events and the development of the phenomenon of vorticity. The results show the improvement presented in some areas of the structure from the stabilization of the water flow through of the fluid-structure interaction change, the modification of the geometry and roughness, minimizing the presence of vertical vortices, cavitation, and surrounding areas. This allows us to conclude that traditional hydraulic do not consider the real physical flow behavior within the structure and neither the subsequent phenomena that develop, establishing as a starting point the need to rethink the design of the bottom rack intakes.

scholarly journals Three-Dimensional Simulation of Fluid–Structure Interaction Problems Using Monolithic Semi-Implicit Algorithm

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 94 ◽  
Author(s):  
Cornel Marius Murea
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Arbitrary Lagrangian Eulerian ◽  
Time Step ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dimensional Simulation ◽  
Updated Lagrangian

A monolithic semi-implicit method is presented for three-dimensional simulation of fluid–structure interaction problems. The updated Lagrangian framework is used for the structure modeled by linear elasticity equation and, for the fluid governed by the Navier–Stokes equations, we employ the Arbitrary Lagrangian Eulerian method. We use a global mesh for the fluid–structure domain where the fluid–structure interface is an interior boundary. The continuity of velocity at the interface is automatically satisfied by using globally continuous finite element for the velocity in the fluid–structure mesh. The method is fast because we solve only a linear system at each time step. Three-dimensional numerical tests are presented.

Experimental and Numerical Analysis for Fluid-Structure Interaction for an Enclosed Hexagonal Assembly

2014 ◽  
Author(s):  
Lucia Sargentini ◽  
Benjamin Cariteau ◽  
Morena Angelucci
Keyword(s):  
Numerical Method ◽  
Stokes Equations ◽  
Interaction Analysis ◽  
Flow Behavior ◽  
Fluid Structure Interaction ◽  
Water Injection ◽  
Free Vibrations ◽  
Navier Stokes ◽  
Fluid Structure ◽  
Structure Interaction

This paper is related to fluid-structure interaction analysis of sodium cooled fast reactors core (Na-FBR). Sudden liquid evacuation between assemblies could lead to overall core movements (flowering and compaction) causing variations of core reactivity. The comprehension of the structure behavior during the evacuation could improve the knowledge about some SCRAMs for negative reactivity occurred in PHÉNIX reactor and could contribute on the study of the dynamic behavior of a FBR core. An experimental facility (PISE-2c) is designed composed by a Poly-methyl methacrylate hexagonal rods (2D-plan similitude with PHÉNIX assembly) with a very thin gap between assemblies. Another experimental device (PISE-1a) is designed and composed by a single hexagonal rod for testing the dynamic characteristics. Different experiments are envisaged: free vibrations and oscillations during water injection. A phenomenological analysis is reported showing the flow behavior in the gap and the structure response. Also computational simulations are presented in this paper. An efficient numerical method is used to solve Navier-Stokes equations coupled with structure dynamic equation. The numerical method is verified by the comparison of analytic models and experiments.

Fluid-Structure Interactive Simulation Using a Virtual Flux Method

2011 ◽  
Author(s):  
Koji Morinishi ◽  
Tomohiro Fukui
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Combustion Process ◽  
Valve Lift ◽  
Navier Stokes ◽  
Connecting Rod ◽  
Flux Method ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Virtual Flux

This paper describes the resent development of a virtual flux method for simulating fluid-structure interaction problems. The virtual flux method is one of the sharp interface Cartesian grid methods. The numerical flux across the interface is replaced with the virtual flux so that proper interface conditions must be satisfied there. In this study, the virtual flux method is applied to numerical flow simulations about reciprocating engines. The compressible Navier-Stokes equations are coupled with the equation of motion of the piston, connecting rod, and crank system. Intake and exhaust valves are lifted up and down according with the crank angle in the intake and exhaust strokes. Instead of modeling the complex fuel combustion process, a proper amount of energy is added to the Navier-Stokes equation at the beginning of each expansion stroke, to retain the four stroke engine cycle at a constant revolution rate. Initially the engine is started by starter motor force, which is added for a few seconds. The engine comes to work at the revolution rate intended after some initial transition cycles. With designing the intake and exhaust valve lift properly, intake mass and revolution rate are improved by several percent. It is confirmed that the virtual flux method is easily applicable to the simulation of fluid-structure interaction problems.

scholarly journals Modelling and numerical simulation of vibrations induced by mixed faults of a rotor system immersed in an incompressible viscous fluid

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881934 ◽  
Author(s):  
Bernard Xavier Tchomeni ◽  
Alfayo Alugongo
Keyword(s):  
Viscous Fluid ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Fluid Motion ◽  
Engineering Application ◽  
Incompressible Viscous Fluid ◽  
Navier Stokes ◽  
Energy Principle ◽  
Fluid Structure ◽  
Structure Interaction

Extraction of features of a specific signal in fluid–structure interaction is among the hottest problems in the field of mechanics. Yet, a comprehensive study of such problems remains a challenge due to their high nonlinearity and multidisciplinary nature. The study presented in this article is focused on a particular engineering application of fluid–structure interaction. The governing equation of a spinning rotor submerged in an incompressible viscous fluid is modelled by means of well-established dissipative energy principle, yielding a highly coupled 3-degree-of-freedom system with strong nonlinear terms. A two-dimensional model of the Navier–Stokes equations for the incompressible flow is developed for the viscous fluid motion around the spinning rotor under high fluctuations induced by unbalance, rotor–stator rub and a crack. The extracted features through frequency spectrum, orbit patterns and rotor-coupled deflection revealed that the performances of rotor systems are highly impacted by the hydrodynamic terms which are the sources of multiple frequency response. The results showed that the complex fluid–rotor model yields good analysis of fault diagnosis, and responses at more than one parametric resonance appear and reach a point of complex feature extractions when more than one fault coexists in the system. Furthermore, a nonlinear denoising by thresholding the wavelet coefficients is performed to overcome the complexity of discretization and for effective multiple fault diagnoses.

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