摘要
Transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. The waveform distortion due to viscous dissipation and elastic expansion of pipe wall was characterized by a dimensionless transmission number. The damping coefficients of pressure waves were found to be related to the roots of Bessel function. An exact solution of pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and transmission number was studied. The problem was also calculated with a general-purpose computer code, COMMIX, which solves exact mass conservation equation and Navier-Stokes equations. The computational results of the COMMIX code agreed well with the analytical solutions.
Transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. The waveform distortion due to viscous dissipation and elastic expansion of pipe wall was characterized by a dimensionless transmission number. The damping coefficients of pressure waves were found to be related to the roots of Bessel function. An exact solution of pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and transmission number was studied. The problem was also calculated with a general-purpose computer code, COMMIX, which solves exact mass conservation equation and Navier-Stokes equations. The computational results of the COMMIX code agreed well with the analytical solutions.
