Author(s): Tiit Koppel; Leo Aino La
Linked Author(s):
Keywords: Water hammer models; Asymptotic derivat ion; Wall shear
Abstract: Practical so lut ions o f the Navier-Stokes and cont inuity equat ions for applied engineering problems o f the transient pipe flow are very troublesome both analyt ically and numerically. Therefore, the use of approximate one- and two-dimensional mathemat ica l models is inevitable. Several approximate models are well known. A unified asymptotic derivat ion o f the one- and two-dimensional water hammer equat ions from the threedimensional Navier-Stokes equations for a compressible fluid is given. The high- and lowfrequency approximat ions of these equat ions are obtained. By expressing the wall shear stress through pressure the water hammer equat ions are represented in a new alternat ive form.
Year: 2007