Research & Development at Dynaflow, Inc. has yielded a new product, the ABS Cavitation Susceptibility MeterTM (ABS-CSMTM) based on an acoustic technique to generate and measure cavitation inception in a liquid. This product is now offered to users to enable quantification of the cavitation susceptibility, also known as liquid ‘quality’ or tensile strength of.

Principle of Operation
The ABS-CSMTM system uses a similar hardware set as our bubble size measurement instrument, the ABS Acoustic, Bubble Spectrometer®© system, and interrogates the cavitation susceptibility of a liquid sample by systematically increasing the excitation voltage applied to an acoustic pressure generator in order to create an oscillating pressure field to excite any bubble nuclei in the liquid. As the intensity of the oscillating pressure field exceeds a threshold, cavitation events (explosive bubble growth and collapse) start to occur and high frequency collapsing bubble pressures are emitted. These are then detected by a high sensitivity pressure probe. Dynaflow proprietary software controls the instrument operation, the acoustic emission and detection, and the signal analysis. The initiation of cavitation is detected as a sudden significant increase in the received signal of interest.

Sample cavitation susceptibility measurement results in water samples with different tensile strength.

The  ABS-CSMTM utilizes the following major hardware: a Desktop PC, an ABS interface box, a power amplifier, and a high frequency pressure sensor. The ABS-CSMTM can also be purchased as an add-on to an  ABS Acoustic Bubble Spectrometer®© system to take advantage of customer existing hardware and software. The use of a power amplifier can be avoided for applications which accept application of a pressure drop to the sample through a vacuum pump or a controlled flow.

The main advantages of the ABS-CSMTM relative to other cavitation susceptibility meters are as follows:

  • Tests and results are obtained in minutes
  • No post-processing is required
  • The measurement can be done for a sample liquid with or without flow
  • The use of acoustic excitation makes it suitable for measurement in clear or opaque liquids and in presence or absence of particles
  • There is no need for expensive means to cavitate individual bubbles and count them
  • It can be made portable and is easy to setup
  • The system can be custom made to the user specifications

Major components used in the ABS Cavitation Susceptibility MeterTM

System setup sketch for an add-on option of ABS-CSMTM in a triple-set ABS Acoustic Bubble Spectrometer®© system

ABS-CSMTM sensor unit embedded in a by-pass configuration that is used for a triple-set ABS Acoustic Bubble Spectrometer®© system. The sensor unit includes an excitation hydrophone and a high sensitivity pressure transducer which are seen on the right