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  • Author or Editor: Dan Liberzon x
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Dan Liberzon
and
Lev Shemer

Abstract

An application of a commercially available and inexpensive pressure probe and transducer, originally designed for pressure drop measurements in air conditioning conduits, is suggested for accurate and reliable measurements of static pressure fluctuations in airflow, with a particular application to wind interaction with water waves. It is demonstrated that this static pressure probe is a robust instrument that offers efficient dynamic pressure elimination while having low directional sensitivity and sufficiently high dynamic response. A series of measurements in a wind-wave flume was carried out to validate the characteristics of the sensor and of the pressure transducer.

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Dan Liberzon
,
Alexandru Vreme
,
Sagi Knobler
, and
Itamar Bentwich

Abstract

We report the development of a new method for accurate detection of breaking water waves that addresses the need for an accurate and cost-effective method that is independent of human decisions. The new detection method, which enables the detection of breakers using only surface elevation fluctuation measurements from a single wave gauge, supports the development of a new method for research relating to water waves and wind–wave interactions. According to the proposed method, detection is based on the use of the phase-time method to identify breaking-associated patterns in the instantaneous frequency variations of surface elevation fluctuations. A wavelet-based pattern recognition algorithm is devised to detect such patterns and provide accurate detection of breakers in the examined records. Validation and performance tests, conducted using both laboratory and open-sea data, including mechanically generated and wind-forced waves, are reported as well. These tests allow us to derive a set of parameters that assure high detection accuracy rates. The method is shown to be capable to achieve a positive detection rate exceeding 90%.

Open access