Slender-body theory

In fluid dynamics and electrostatics, slender-body theory is a methodology that can be used to take advantage of the slenderness of a body to obtain an approximation to a field surrounding it and/or the net effect of the field on the body. Principal applications are to Stokes flow — at very low Reynolds numbers — and in electrostatics. In fluid dynamics and electrostatics, slender-body theory is a methodology that can be used to take advantage of the slenderness of a body to obtain an approximation to a field surrounding it and/or the net effect of the field on the body. Principal applications are to Stokes flow — at very low Reynolds numbers — and in electrostatics. Consider slender body of length ℓ {displaystyle ell } and typical diameter 2 a {displaystyle 2a} with ℓ ≫ a {displaystyle ell gg a} , surrounded by fluid of viscosity μ {displaystyle mu } whose motion is governed by the Stokes equations. Note that the Stokes' paradox implies that the limit of infinite aspect ratio ℓ / a → ∞ {displaystyle ell /a ightarrow infty } is singular, as no Stokes flow can exist around an infinite cylinder.