بر رسی فشارهای دینامیکی وارد بر صفحه موج نفوذپذیر تحت تابش امواج منظم

نویسندگان

1 دانشجوی دکتری دانشگاه تبریز

2 استاد دانشکده کشاورزی- گروه مهندسی آب

3 استاد دانشکده عمران- گروه مهندسی آب

چکیده

برای طراحی موثر و کارای یک صفحه موج تخمین دقیق فشار دینامیکی و نیروی موج ضروری می‌باشد. این مطالعه به بررسی فشار وارد بر اجزای سازه‌ی یک صفحه موج متشکل از لوله‌های افقی که با فاصله مشخص کنار هم قرار گرفته اند، می‌پردازد. این صفحه امکان تبادل آب دریا در منطقه ساحلی و جذب موثر انرژی را فراهم می‌کند. به این منظور آزمایش‌های فیزیکی بر روی سازه صفحه موج تحت تابش امواج منظم در 3 ارتفاع و 6 پریود موج در عمق آب ثابت 6/0 متر انجام گرفت. در این آزمایش ها از 3 قطر برای استوانه‌های تشکیل‌دهنده سازه استفاده گردید. فشار دینامیکی وارد بر استوانه‌های صفحه موج در امتداد عمقی و پیرامون سازه توسط مبدل فشار برداشت گردید. نتایج نشان داد افزایش تخلخل موجب کاهش تغییرات فشار دینامیکی موج می‌گردد و با افزایش ارتفاع موج تابشی نوسانات فشار برای تخلخل‌های مختلف افزایش می-یابد. هم‌چنین حداکثر تغییرات فشار دینامیکی موج غالبا در زاویه صفر برخورد موج با استوانه‌های سازه ایجاد نمی‌گردد و معمولا در زوایای بیش‌تر از 45 درجه، شاهد افزایش دامنه‌ نوسانات فشار دینامیکی بودیم.

کلیدواژه‌ها


عنوان مقاله [English]

Waves Investigation of Dynamic Pressure on Wave Screen under Regular

نویسنده [English]

  • Naval Azam 1
1 Tabriz university-PHD Candidate
چکیده [English]

For a cost-effective design of wave screen, an accurate estimation of dynamic pressures and wave forces is needed. This study investigated the acting dynamic pressure on elements of wave screen consist of horizontal pipes with constant distance between them. This wave screen can be beneficial for convection and interchange of seawater within the harbor district and, furthermore, perform wave absorption effectively. The physical experiments were performed by considering regular waves under 3 heights and 6 periods of waves and 3 diameters of pipes wave screen. The tests were carried out for 0.6m still water depth value. Dynamic pressure distribution along and around pipes was obtained employing pressure transducers. The experimental results indicated that increasing the porosity decrease pressure difference and with increasing the incident wave height for different porosity increase pressure difference. Furthermore, the maximum dynamic pressure difference does not often occur at the section normal to the wave direction.

کلیدواژه‌ها [English]

  • Regular Wave
  • Porosity
  • Wave Screen
  • dynamic pressure
  • Breakwater
Alkhalidi M, Neelamani S and Assad AAH, 2015. Wave force and dynamic pressure on slotted vertical wave barriers with an impermeable wall in random wave fields. Ocean Engineering 109 (1): 1–6.
Anandkumar G, Sundar V, Graw KU and Kaldenhoff H, 1995. Pressure and forces on inclined cylinders due to regullar waves. Ocean Engineering 22 (7): 747–759.
Bergmann H and Oumeraci H, 1998. Wave pressure distribution on permeable vertical walls. 26th International Conference on Coastal Engineering. Copenhagen, Denmark, 2042–2055.
Chen XF, Li YC, Wang YX, Dong GH and Bai X, 2003. Numerical simulation of wave interaction with perforated caissons breakwaters. China Ocean Engineering 17(1): 33–43.
Dean RG and Dalrymple RA, 1991. Water wave mechanics for engineers and scientists. World scientific. Delaware University, USA. 371p.
Dhinakaran G, Sundar V, Sundaravadivelu R and Graw KU, 2002. Dynamic pressures and forces exerted on impermeable and seaside perforated semicircular breakwaters due to regular waves. Ocean Engineering 29(15): 1981–2004.
Hall K, 2000. Wave transmission through multi-layer wave screens. M.Sc. thesis at Queen's university, Kingston, Ontario, Canada.
Hughse SA, 1993. Physical Models and Laboratory Techniques in Coastal Engineering. World scientific. Delaware University, USA, 568p.
Huang ZH and Li L, 2011. Hydraulic performance and wave loadings of perforated/slotted coastal structures: a review. Ocean Engineering 38(1): 1031–1053.
Kisacik D, Troch P and Bogaert PV, 2012. Description of loading conditions due to violent wave impacts on a vertical structure with an overhanging horizontal cantilever slab. Coastal Engineering 60(1): 201–226.
Koraim AS, Iskander MM and Elsayed WR, 2014. Hydrodynamic performance of double rows of piles suspending horizontal c shaped bars. Journal of Coastal Engineering 84: 81-96.
Krishnakumar C, Sunder V and Sannasiraj SA, 2010. Pressures and forces due to directional waves on a vertical wall fronted by wave screens. Applied Ocean Research 32 (1): 1-10.
Neelamani S and Sandhya N, 2005. Surface roughness effect of vertical and sloped seawall in incident random wave fields. Ocean Engineering. 32: 395–416.
Reddy MS and Neelamanit S, 1992. Wave transmission and reflection characteristics of a partially immersed rigid vertical barrier. Ocean Engineering 19(1): 313–325.
Sahoo T, Lee MM, and Chwang AT, 2000. Trapping and generation of waves by vertical porous structures. Journal of Engineering Mechanics. 126 (10): 1074-1082.
Shih RS, 2016. Investigation of random wave impact on highly pervious pipe breakwaters. Ocean Research 58 (1): 146–163.
Sorensen RM, 2006. Basic coastal Engineering. Springer Science. Lehigh University, Bethlehem, Pennsylvania. 331p.
Sundar V, Koola PM and Schlenkhoff AU, 1999. Dynamic pressure on inclined cylinders due to freak waves. Ocean Engineering 26 (9): 841–863.
Taqi A, Neelamani S, Al-Khalidi M and Al-Salem K, 2013. Experimental investigation to assess the wave energy dissipation for arrays of vertical slotted barriers. In: Proceedings of the 35th IAHR World Congress. Chengdu, China, A11863, (2), 1–15.
Yagci O, Kirca VSO, Kabdasli MS, Celik AO, Unal NE and Aydingakko A, 2006. An experimental model application of wavescreen: dynamic pressure, Water particle velocity, and wave measurements. Ocean Engineering 33(1): 1299-1321.