In
fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them.
It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and bio ...
a Riabouchinsky solid is a technique used for approximating
boundary layer separation
In fluid dynamics, flow separation or boundary layer separation is the detachment of a boundary layer from a surface into a wake.
A boundary layer exists whenever there is relative movement between a fluid and a solid surface with viscous fo ...
from a
bluff body
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag equ ...
using
potential flow
In fluid dynamics, potential flow (or ideal flow) describes the velocity field as the gradient of a scalar function: the velocity potential. As a result, a potential flow is characterized by an irrotational velocity field, which is a valid appr ...
. It is named after
Dimitri Pavlovitch Riabouchinsky.
Riabouchinsky solids are typically used for analysing the behaviour of bodies moving through otherwise quiescent fluid (examples would include moving cars, or buildings in a windfield).
Typically the
streamline
Streamline may refer to:
Business
* Streamline Air, American regional airline
* Adobe Streamline, a discontinued line tracing program made by Adobe Systems
* Streamline Cars, the company responsible for making the Burney car
Engineering
...
that touches the edge of the body is modelled as having no
transverse pressure gradient and thus may be styled as a
free surface
In physics, a free surface is the surface of a fluid that is subject to zero parallel shear stress,
such as the interface between two homogeneous fluids.
An example of two such homogeneous fluids would be a body of water (liquid) and the air in ...
after separation.
The use of Riabouchinsky solids renders
d'Alembert's paradox
In fluid dynamics, d'Alembert's paradox (or the hydrodynamic paradox) is a contradiction reached in 1752 by French mathematician Jean le Rond d'Alembert. D'Alembert proved that – for incompressible and inviscid potential flow – the drag for ...
void; the technique typically gives reasonable estimates for the drag offered by bluff bodies moving through inviscid fluids.
References
Fluid dynamics
Russian inventions
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