E23 Lift to Drag Characteristics of Three Dimensional Wing at Low Reynolds Number Using Small Variable-Pressure Wind Tunnel

The translation and rotation of non-spherical particles, such as ellipsoidal, cylindric or disk-like pigment particles, in a Couette flow system similar to a blade coating system in the paper industry6 have been successfully simulated by using the lattice-Boltzmann method combined with Newtonian dynamic simulations. Hydrodynamic forces and torques are obtained by the use of boundary conditions which match the moving surface of solid particles. Then Euler equations have been integrated to include three-dimensional rotations of the suspensions by using four quaternion parameters as generalized coordinates. The three-dimensional rotations have been clearly observed. Consequently, the motion of the particles suspended in fluids of both low-Reynolds-number and finite-Reynolds-number, up to several hundreds, has been studied. It appears that the 3D translation and rotation of the non-spherical particles are more clearly observed in a high-Reynolds-number fluid than in a low-Reynolds-number fluid.

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Performance characteristics from wind-tunnel tests of a low-Reynolds-number airfoil

10.2514/6.1988-607 ◽

1988 ◽

Cited By ~ 11

Author(s):

ROBERT MCGHEE ◽

GREGORY JONES ◽

REMI JOUTY

Keyword(s):

Reynolds Number ◽

Wind Tunnel ◽

Low Reynolds Number ◽

Performance Characteristics ◽

Wind Tunnel Tests ◽

Low Reynolds ◽

Low Reynolds Number Airfoil

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The motion of rigid particles in a shear flow at low Reynolds number

Journal of Fluid Mechanics ◽

10.1017/s002211206200124x ◽

1962 ◽

Vol 14 (2) ◽

pp. 284-304 ◽

Cited By ~ 518

Author(s):

F. P. Bretherton

Keyword(s):

Reynolds Number ◽

Low Reynolds Number ◽

Three Dimensional ◽

Body Of Revolution ◽

Rigid Particles ◽

Unidirectional Flow ◽

Uniform Shear ◽

Ellipsoid Of Revolution ◽

Low Reynolds ◽

Bounding Surfaces

According to Jeffery (1923) the axis of an isolated rigid neutrally buoyant ellipsoid of revolution in a uniform simple shear at low Reynolds number moves in one of a family of closed periodic orbits, the centre of the particle moving with the velocity of the undisturbed fluid at that point. The present work is a theoretical investigation of how far the orbit of a particle of more general shape in a non-uniform shear in the presence of rigid boundaries may be expected to be qualitatively similar. Inertial and non-Newtonian effects are entirely neglected.The orientation of the axis of almost any body of revolution is a periodic function of time in any unidirectional flow, and also in a Couette viscometer. This is also true if there is a gravitational force on the particle in the direction of the streamlines. There is no lateral drift. On the other hand, certain extreme shapes, including some bodies of revolution, will assume one of two orientations and migrate to the bounding surfaces or to the centre of the flow. In any constant slightly three-dimensional uniform shear any body of revolution will ultimately assume a preferred orientation.

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