Keywords
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Slamming, Impact pressure, Sampling rate, Wedge, Water entry experiment
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Abstract
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Water entry experiment is the most reliable method by which impact pressures on marine structures are measured. Several parameters have to be controlled during the water entry experiments to obtain accurate and
reliable results. Sampling rate of data acquisition system is one of the influencing factors. In this paper, the effect
of sampling rate on impact pressure on wedge water entry experiments is investigated. A wide range of wedges
with deadrise angles of 5°–35° are dropped into water at the entry velocity of 3.13 m/s and impact pressures are
recorded with different sampling rates. Results are compared to analyze the effect of sampling rate on outcomes.
Finally, to mitigate the negative aspects, some thresholds of sampling rate are determined for different wedges. It
was found that for wedges with deadrise angles of 25° and higher, a sampling rate of 25 kHz is adequate for this
configuration. This sampling rate; however, is not appropriate for deadrise angles lower than 20° where a higher
rate is needed. Results indicate that the acceptable sampling rate for a wedge of 5° deadrise angle is 600 kHz at
water entry velocity of 3.13 m/s.
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