# Drag force on a rigid cylinder when velocity is parallel to its axis(Slender-body theory)

## Description

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.

Drag force on a rigid cylinder having a moving velocity parallel to its axis, is depended on the length of the cylinder (length much longer than the radius of the base), the dynamic viscosity of the fluid and the velocity of the slender body.

## Variables

F | Drag force on the rigid cylinder (N) |

π | pi |

μ | Dynamic viscosity of the fluid (Pa*s) |

l | Long length of the cylinder (m) |

u | Velosity of the moving cylinder (m/s) |

a | Radius of the base of the cylinder (m) |

## Categories

### External links