Closure to “Discussion of ‘An Investigation of the Effect of Cavitation Bubbles on the Momentum Loss in Transient Pipe Flow’” (1971, ASME J. Basic Eng., 93, pp. 7–10)

1971 ◽  
Vol 93 (1) ◽  
pp. 10-10
Author(s):  
M. E. Weyler ◽  
V. L. Streeter ◽  
P. S. Larsen
Keyword(s):  
Pipe Flow ◽  
Momentum Loss ◽  
Cavitation Bubbles ◽  
Transient Pipe Flow

An Investigation of the Effect of Cavitation Bubbles on the Momentum Loss in Transient Pipe Flow

1971 ◽  
Vol 93 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. E. Weyler ◽  
V. L. Streeter ◽  
P. S. Larsen
Keyword(s):  
Shear Stress ◽  
Physical Model ◽  
Pipe Flow ◽  
Pressure Waves ◽  
Separation Flow ◽  
Column Separation ◽  
Momentum Loss ◽  
Transient Pipe Flow ◽  
Pressure Changes ◽  
Separation Conditions

Based on experimental observations of pressure changes during hydraulic transients in pipe flow with column separation, a physical model was hypothesized and correlated with the data to provide a semiempirical “bubble shear stress” which can be used to predict the increased momentum loss observed under column separation conditions. The “bubble shear stress” arises from the nonadiabatic expansion and collapse of gas bubbles present throughout the low pressure column separation flow, and is found to be proportional to the strength of passing pressure waves, and a weak function of the amount of gas trapped on the pipe walls.

Numerical and experimental investigation of transient pipe flow

1994 ◽  
Vol 32 (5) ◽  
pp. 689-706 ◽  
Author(s):  
Amgad S. Elansary ◽  
M. Hanif Chaudhry ◽  
Walter Silva
Keyword(s):  
Experimental Investigation ◽  
Pipe Flow ◽  
Transient Pipe Flow

scholarly journals Behavior of turbulent slug in transient pipe flow.

1988 ◽  
Vol 54 (499) ◽  
pp. 541-546
Author(s):  
Manabu IGUCHI ◽  
Munekazu OHMI ◽  
Youichi FUJII
Keyword(s):  
Pipe Flow ◽  
Transient Pipe Flow

scholarly journals Modeling Transient Pipe Flow in Plastic Pipes with Modified Discrete Bubble Cavitation Model

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6756
Author(s):  
Kamil Urbanowicz ◽  
Anton Bergant ◽  
Apoloniusz Kodura ◽  
Michał Kubrak ◽  
Agnieszka Malesińska ◽  
...  
Keyword(s):  
Differential Equations ◽  
Pipe Flow ◽  
Numerical Solutions ◽  
Viscoelastic Behavior ◽  
Wall Material ◽  
Creep Function ◽  
Water Supply Systems ◽  
Two Phase ◽  
Plastic Pipes ◽  
Transient Pipe Flow

Most of today’s water supply systems are based on plastic pipes. They are characterized by the retarded strain (RS) that takes place in the walls of these pipes. The occurrence of RS increases energy losses and leads to a different form of the basic equations describing the transient pipe flow. In this paper, the RS is calculated with the use of convolution integral of the local derivative of pressure and creep function that describes the viscoelastic behavior of the pipe-wall material. The main equations of a discrete bubble cavity model (DBCM) are based on a momentum equation of two-phase vaporous cavitating flow and continuity equations written initially separately for the gas and liquid phase. In transient flows, another important source of pressure damping is skin friction. Accordingly, the wall shear stress model also required necessary modifications. The final partial derivative set of equations was solved with the use of the method of characteristics (MOC), which transforms the original set of partial differential equations (PDE) into a set of ordinary differential equations (ODE). The developed numerical solutions along with the appropriate boundary conditions formed a basis to write a computer program that was used in comparison analysis. The comparisons between computed and measured results showed that the novel modified DBCM predicts pressure and velocity waveforms including cavitation and retarded strain effects with an acceptable accuracy. It was noticed that the influence of unsteady friction on damping of pressure waves was much smaller than the influence of retarded strain.

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