Surfability of an ASR in irregular waves

摘要: Wave surfing is a popular sport all around the world where conditions allow for it. Waves preferred by surfers are higher than 1 meter, have certain hollow breaker shape (plunger) and angle under which wave breaks, peel angle, within 30-70 degrees. Also in Netherlands becomes increasingly but Dutch far from ideal because firstly almost always spilling not desirable shape, secondly angles range 60-90 degrees most of time. To alter breaking characteristics submerged structure can be built: so called Artificial Surf Reef (ASR). An ASR has been designed van Ettinger (2005) to reduce rip currents sides structure. The that was tested for, namely bichromatic waves, representative south North Sea coast line located. Therefore physical model tests done with irregular conditions, typical found this part Sea, determine effectiveness on surfability waves. One locations an Scheveningen area determined numerical simulation SWAN. From buoy data it what common surfable these used boundary model. direction waves come often sector 30° 240°-270° (Nautical). Only chance occurrence more 24 hours year height meter taken into account. output as test experimental study (scale 1:15) Laboratory Fluid Mechanics at Faculty Civil Engineering Geosciences. carried out constant water depth, representing situation without tides. Three different levels recorded analyze influence tidal level fluctuations surfability. parameters are: â Peel Length ride Breaker type These estimated recordings behavior reef (taken above) each second recording five images extracted location break point tracked. image length estimated. looking foam intensity created wave: larger Irribarren numbers (for I¾b<3). This explained fact air enclosed due intense breaking. With algorithms developed individual analyzed. results estimate made total number coming 240°-270°, 7180 if no tides would present. twofold: shapes, possible lengths shorter. Tides will approximately 40%, brings 4300