Slip in Couette flow with pressure gradient: Theoretical and experimental investigation of hydrodynamic characteristics considering slip effect

In this study, the hydrodynamic characteristics are investigated for magneto-micropolar fluid flow through an inclined channel of parallel plates with constant pressure gradient. The lower plate is maintained at constant temperature and upper plate at a constant heat flux. The governing equations which are continuity, momentum and energy are are solved numerically by Explicit Runge-Kutta. The effect of characteristic parameters is discussed on velocity and microrotation in different diagrams. The nonlinear parameter affected the velocity microrotation diagrams. An increase in the value of Hartmann number slows down the movement of the fluid in the channel. The application of the magnetic field induces resistive force acting in the opposite direction of the flow, thus causing its deceleration. Also the effect of pressure gradient is investigated on velocity and microrotation in different diagrams.

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Numerical and Experimental Investigation of Hydrodynamic Characteristics of Deformable Hydrofoils

Journal of Ship Research ◽

10.5957/jsr.2009.53.4.214 ◽

2009 ◽

Vol 53 (04) ◽

pp. 214-226

Author(s):

Antoine Ducoin ◽

François Deniset ◽

Jacques André Astolfi ◽

Jean-François Sigrist

Keyword(s):

Experimental Investigation ◽

Structure Design ◽

Hydrodynamic Characteristics ◽

The Finite Element Method ◽

Fluid Structure ◽

Cavitation Inception ◽

Marine Structure ◽

Structure Problem ◽

Volume Method ◽

Processing Device

The present paper is concerned with the numerical and experimental investigation of the hydroelastic behavior of a deformable hydrofoil in a uniform flow. The study is developed within the general framework of marine structure design and sizing. An experimental setup is developed in the IRENav hydrodynamic tunnel in which a cambered rectangular hydrofoil is mounted. An image-processing device enables the visualization of the foil displacement. As for the numerical part, the structure problem is solved with the finite element method, while the fluid problem is solved with the finite volume method using two distinct numerical codes that are coupled through an iterative algorithm based on the exchange of the boundary conditions at the fluid-structure interface. Results obtained from the coupled fluid-structure computations including deformation and hydrodynamic coefficients are presented. The influence of the fluid-structure coupling is evaluated through comparisons with "noncoupled" simulations. The numerical simulations are in very good agreement with the experimental results and highlight the importance of the fluid-structure coupling consideration. Particular attention is paid to the pressure distribution modification on the hydrofoil as a result of deformations that can lead to an advance of the cavitation inception, which is of paramount importance for naval applications.

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