A Field Meter for Sound Velocity Measurements

Sound field separation with sound pressure and particle velocity measurements.

In conventional near-field acoustic holography (NAH) it is not possible to distinguish between sound from the two sides of the array, thus, it is a requirement that all the sources are confined to only one side and radiate into a free field. When this requirement cannot be fulfilled, sound field separation techniques make it possible to distinguish between outgoing and incoming waves from the t...

Water Velocity Measurements in Open Channels Using Volumetric Current Meter (VCM)

An innovative Volumetric Current Meter (VCM) was designed in order to allow quick velocity measurements in open channels. At first, the coefficient of velocity (Cv) of the device was determined through calibration under different water velocities in the laboratory. The measurement performance was verified by measurements performed in similar flows in irrigation channels using an ordinary curren...

A sound field separation technique based on measurements with pressure-velocity probes

A sound field separation technique based on measurements with pressure-velocity probes (L).

It has recently been shown that statistically optimized near field acoustic holography based on measurement with an array of pressure-velocity transducers makes it possible to distinguish between sources on the two sides of the array and thus suppress the influence of a disturbing source [F. Jacobsen and V. Jaud, J. Acoust. Soc. Am. 121, 1550-1558 (2007)]. However, the suggested technique uses ...

Development of a Low Cost and Safe PIV for Mean Flow Velocity and Reynolds Stress Measurements

In this study, a white light particle image velocimetry (WL PIV) system which employs a light sheet generated with a flash was used. The system was developed in order to provide a cost-efficient and safe alternative to laser systems while keeping the accuracy limits required for hydraulic model tests. To investigate the accuracy of WL PIV method under different flow conditions, experiments were...