On the flows produced by sudden application of a constant pressure gradient or by impulsive motion of a boundary |
| |
Authors: | MEmin Erdo?an |
| |
Institution: | I.T.Ü., Makina Fakültesi, 80191, Gümü?suyu, Istanbul, Turkey |
| |
Abstract: | Some properties of the time-dependent Navier-Stokes equations are discussed for flows impulsively started from rest by sudden application of a constant pressure gradient or by the impulsive motion of a boundary. Five illustrative examples are given. They are: unsteady flow in a circular cylinder moving parallel to its length, starting flow in a circular pipe, unsteady flow in a rotating cylinder, starting flow in a rectangular channel moving parallel to its length and unsteady flow in a channel of rectangular cross-section. It is found that the expressions of the quantities such as velocity, flux and skin friction are in series forms which may be rapidly convergent for large values of the time but slowly convergent for small values of the time or vice versa. It is shown that if their expressions can be found for one of large values of the time or small values of the time, these expressions can be used for the other. |
| |
Keywords: | Unsteady pipe flow Viscous fluid Impulsive motion Starting flow |
本文献已被 ScienceDirect 等数据库收录! |
|