American Society of Civil Engineers


Nonreflective Boundary Design via Remote Sensing and Proportional-Integral-Derivative Control Valve


by Qinfen (Katherine) Zhang, Ph.D., P.E., (corresponding author), (Oak Ridge National Laboratory (UT-Battelle, LLC), One Bethel Valley Rd., PO Box 2008, Oak Ridge, TN 37831-6308. E-mail: Zhangq1@ornl.gov), Bryan Karney, M.ASCE, (Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto, ON, Canada, M5S 1A4. E-mail: karney@ecf.utoronto.ca), and Stanislav Pejovic, (Professor Emeritus, 300 Webb Dr. #1411, Mississauga, Ontario, Canada L5B 3W3. E-mail: pejovics@asme.org)

Journal of Hydraulic Engineering, Vol. 137, No. 11, November 2011, pp. 1477-1489, (doi:  http://dx.doi.org/10.1061/(ASCE)HY.1943-7900.0000403)

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Document type: Journal Paper
Abstract: This paper develops the concept of a nonreflective (or semireflective) boundary condition using the combination of a remote sensor and a control system to modulate a relief valve. The essential idea is to sense the pressure change at a remote location and then to use the measured data to adjust the opening of an active control valve at the end of the line to eliminate or attenuate the wave reflections at the valve, thus controlling system transient pressures. This novel idea is shown here through numerical simulation to have considerable potential for transient protection. Using this model, wave reflections and resonance can be effectively eliminated for frictionless pipelines or initial no-flow conditions and can be better controlled in more realistic pipelines for a range of transient disturbances. In addition, the features of even-order harmonics and nonreflective boundary conditions during steady oscillation, obtained through time domain transient analysis, are verified by hydraulic impedance analysis in the frequency domain.


ASCE Subject Headings:
Design
Energy dissipation
Hydraulic transients
Mathematical models
Pipe flow
Unsteady flow
Water hammer
Water pipelines
Wave propagation
Wave reflection
Resonance

Author Keywords:
Design
Energy dissipation
Hydraulic transients
Mathematical models
Pipe flow
Unsteady flow
Water hammer
Water pipelines
Wave propagation
Wave reflection
Resonance