Pressure Surges Following Water-Column Separation

1961 ◽  
Vol 83 (3) ◽  
pp. 456-458 ◽  
Author(s):  
J. T. Kephart ◽  
Kenneth Davis
Keyword(s):  
Water Column ◽  
Rapid Assessment ◽  
Column Separation ◽  
Water Columns ◽  
Pressure Surge

Equations have been derived using rigid-water-column theory which permit rapid assessment of pressure surge magnitude owing to rejoinder of water columns in pump-discharge lines subsequent to a water-column separation induced by failure of power to the pump drivers. The method is valid only for systems which are equipped with check valves at the pumps.

Comparison of the performance of oscillating water column devices based on arrangements of water columns

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Graphical Form ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Water Columns ◽  
Single Column ◽  
Parallel Arrangement

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.

A Lagrangian wave characteristic method for simulating transient water column separation

2009 ◽  
Vol 101 (6) ◽  
pp. 64-73 ◽  
Author(s):  
Bong Seog Jung ◽  
Paul F. Boulos ◽  
Don J. Wood ◽  
Christopher M. Bros
Keyword(s):  
Water Column ◽  
Characteristic Method ◽  
Wave Characteristic ◽  
Column Separation

Water-Column Separation at Two Pumping Plants

1968 ◽  
Vol 90 (4) ◽  
pp. 521-530 ◽  
Author(s):  
R. J. Brown
Keyword(s):  
Water Column ◽  
Detrimental Effect ◽  
Time History ◽  
Field Measurements ◽  
Measured Data ◽  
Operating Characteristics ◽  
Inherent Difficulty ◽  
Column Separation ◽  
History Of ◽  
Entrained Air

Results of field measurement of transients in two pump discharge lines show that the pressures were greater than had been predicted during design, and a theory and method of analysis are developed which explains the time-history of the transients measured. The field measurements were undertaken because of the complexity of the phenomena and because very little measured data were available. Results are presented graphically along with analytical solutions. Conclusions drawn were: (a) The inherent difficulty of prediction of water-column separation effects is further complicated by the uncertainty about complete pump operating characteristics and actual moment of inertia of pumps and motors; (b) the effects of air and gases entrained in solution in the water must be considered in the analytical solution; and (c) entrained air can have a detrimental effect on the water-hammer transient, i.e., larger pressure surges in the discharge line and higher reverse speeds of the pumps can be caused by its presence.

scholarly journals Power Smoothing and Energy Storage Sizing of Vented Oscillating Water Column Wave Energy Converter Arrays

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1278 ◽  
Author(s):  
Gimara Rajapakse ◽  
Shantha Jayasinghe ◽  
Alan Fleming
Keyword(s):  
Energy Storage ◽  
Water Column ◽  
Wave Energy ◽  
Storage Systems ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Water Columns ◽  
Oscillating Water Columns

Oscillating water column wave energy converter arrays can be arranged to enhance the energy production and quality of power delivered to the grid. This study investigates four different array configurations of vented oscillating water columns and their effect on power quality and capacity of the energy storage systems required to absorb power fluctuation. Configuring the array of vented oscillating water columns as a nearshore detached breakwater allows combining the benefits of their complementary features. This increases the economic optimization of wave energy converters, paving the path to the energy market. The operations of the integration schemes are evaluated using the results obtained from simulations carried out using MATLAB/Simulink software. Simulation results show that the array of vented oscillating water columns and array of vented oscillating water columns as nearshore detached breakwater configurations increase the quality of power delivered to the grid and reduce the capacity of the energy storage systems required.

Sign in / Sign up

Export Citation Format

Share Document