Wave Propagation in a Randomly Layered Medium
The authors briefly outline a problem discussed at length in a paper called Frequency content of randomly scattered signals, by M. Ash, W. Kohler, G. Papanicolaou, M Postel and B. White....
Use of Acoustic Emissions in Identifying Damage Modes in Filament-Wound Composite Pressure Vessels
Characterization of Acoustic Emission Signals
Separation of crack growth signals is of fundamental importance for detecting, locating and determining the significance of an internal flaw using acoustic emission techniques. An analytical...
Acoustic Emission Source Locations in Concrete
The location of acoustic emission (AE) sources can potentially provide information on the fracture process zone in brittle materials such as concrete. Typical AE experiments generate very...
Field Measurements of the Vertical Structure of Suspended Sediment
The use of acoustic backscatter measurements to determine suspended sediment concentration gives a new view of the instantaneous sediment distribution as a function of height above the...
Shoreface Connected Ridges Along the Dutch Coast
Quasi-synoptic current measurements were obtained across the Dutch shoreface connected ridges using an acoustic Doppler current profiler. The measurements are used to evaluate the role...
Higher Frequency Acoustic Measurements of Coarse Bedload Transport
Although sensors have been developed which provide high temporal resolution for the measurement of wave profiles, flow fields and suspended sediment concentrations within the coastal system,...
Laboratory and Field Experience with Cavitation Monitoring of Hydroturbines
When control of cavitation erosion can be accomplished by changes in operating conditions, real-time monitoring of cavitation level is a valuable tool. Three types of cavitation monitors...
Cavitation Noise Investigation of a Pump-Turbine
The results from cavitation noise detection measurements on a 35 MW pump-turbine are presented. Detailed information about the cavitation noise is determined including three-dimensional...
Performance Analysis of Multipath Acoustic Flowmeters Under Various Hydraulic Conditions
Multipath, crossed plane acoustic flowmeters are being increasingly used for hydroelectric turbine efficiency measurement both for acceptance testing and efficiency mapping of units in...
An Acoustic Doppler Discharge-Measurement System
A discharge-measurement system that uses a vessel-mounted acoustic Doppler current profiler has been developed and tested by the U.S. Geological Survey. Discharge measurements using the...
Measuring Ground Water Levels in Wells
Acoustic Flowmeter/Efficiency System Installation at the Niagara Power Project
The New York Power Authority's Robert Moses Niagara Power Project (RMNPP) recently installed an acoustic flowmeter/efficiency system on two 150 MW rated generators. This paper...
Project Control Via Acoustical Sensing
This paper describes ongoing research into automating the process of collecting project control information using acoustical sensing devices. The paper describes how frequency spectra...
Influence of Three Sonic Devices on Fish Behaviour
Three sound emitting devices have been developed to control fish movement in the vicinity of generating stations. These devices have the advantage of increased flexibility in terms of...
Prototype Experience With Acoustic Flowmeters
The acoustic (ultrasonic) flowmeter offers many advantages over other methods for measuring discharge in penstocks for turbine performance tests. It is nonintrusive, inexpensive and may...
A 3 MHz Acoustic Sediment Profiling System
Deepwater Sediment Concentration Profiling in HEBBLE using a One Megahertz Acoustic Backscatter System
Acoustic Determination of Suspended Particle Size Spectra
Acoustic Profiling of Currents and Backscatter Level
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