Experimental study for the hydraulic efficiency of an overtopping type wave energy converter with a circular runup ramp

Yıl 2017, Cilt: 19 Sayı: 1, 118 - 131, 19.06.2017

Mehmet Adil Akgul , Mehmet Sedat Kabdaşlı

https://doi.org/10.25092/baunfbed.322406

Öz

In this study,
overtopping rates on a circular cylindrical overtopping ramp under regular
waves have been measured and hydraulic efficiency of the device as a wave
energy converter has been assessed by analyzing the energy budget of the
overtopped water mass. The study has been carried out by conducting
two-dimensional physical model tests. The variation of overtopping rates with
wave parameters has been studied and an empirical formula has been evaluated
for the estimation of overtopping rates. The efficiency of the system has been
calculated as the ratio of the mean power of the overtopped water mass to the
wave energy flux. Results indicate that the hydraulic efficiency based on the
kinetical komponent can reach 40% for the case of steep waves and the
efficiency is reduced with increasing wavelength.

Anahtar Kelimeler

Wave overtopping, wave energy converter, hydraulic efficiency

Dairesel yüzeyli aşma tipi bir dalga enerjisi dönüştürücüde hidrolik verimin deneysel incelenmesi

Öz

Bu çalışmada, dairesel
silindir formundaki bir tırmanma yüzeyi üzerinde düzenli dalgalar etkisinde
meydana gelecek aşma debileri ölçülmüş ve aşan su kütlesinin enerji bütçesinden
yola çıkılarak sistemin bir dalga enerjisi dönüştürücü olarak hidrolik verimi
incelenmiştir. İki boyutlu fiziksel modelleme teknikleri uygulanarak
gerçekleştirilen çalışmada aşma debilerinin dalga parametreleri ile değişimi
incelenmiş ve debilerin tahmini için ampirik bir bağıntı önerilmiştir. Hidrolik
verim, aşan su kütlesinin ortalama gücünün dalga enerji akısına oranı cinsinden
elde edilmiştir. Çalışma, özellikle kısa periyodlu dalgalarda yapının %40'a
yakın bir hidrolik verim sağladığını göstermekte olup verimin artan dalga boyu
ile azaldığını ortaya koymuştur.

Anahtar Kelimeler

Dalga aşması, dalga enerjisi dönüştürücü, hidrolik verim

Kaynakça

• [1] Cruz, J., Ocean wave energy: Current status and future perspectives, Springer Verlag, Netherlands, (2008).
• [2] Thorpe, T.W., A brief review of wave energy - A report produced for the UK department of trade and industry, ETSU-R120, UK, (1999).
• [3] Bedard, R. and Hagerman, G. Offshore Wave Energy Conversion Devices E2I EPRI Evaluation Report No. E2I-EPRI-WP-004-USRev. 1, Haziran 2004.
• [4] Margheritini, L., Vicinanza, D. and Frigaard, P., SSG wave energy converter: Design, reliability and hydraulic performance of an innovative overtopping device, Renewable Energy, 34, 1371-1380, (2009).
• [5] Kofoed, J.P., Frigaard, P., Friis-Madsen, E. and Sørensen, H.C., Prototype testing of the wave energy converter wave dragon, Renewable Energy, 31, 181-189, (2006).
• [6] Kofoed, J.P., Hald, T. and Frigaard, P., Experimental study of a multi level overtopping wave power device, Proceedings of the 10th Congress of International Maritime Association of the Mediterranean, Crete, (2002).
• [7] Brooke, J., Wave energy conversion, Elsevier Science Ltd., Oxford, (2003).
• [8] Saville, T. JR., Laboratory data on wave runup and overtopping on shore structures, Technical Memorandum No. 64, US Army Corps of Engineers, Beach Erosion Board, Washington, D.C.,(1955).
• [9] Grantham, K.N.,Wave run-up on sloping structures,Transactions of the American Geophysical Union, 34, 5, 720-724, (1953).
• [10] Sibul, O. Flow over reefs and structures by wave action, Transactions of the American Geophysical Union, 36, 1, 61-69, (1955).
• [11] Paape, A., Experimental data on the overtopping of seawalls by waves, Proceedings of the 7th International Conference on Coastal Engineering, 674-681, The Hague,(1960).
• [12] Shi-Igai, K. and Kono, T., Analytical approach on wave overtopping on levees, Proceedings of the 12th International Conference on Coastal Engineering, 563-573, Washington D.C., (1970).
• [13] Weggel, J.R., Wave overtopping equation, Proceedings of the 15th International Conference on Coastal Engineering, 2737-2755, Honolulu, (1976).
• [14] Owen, M.W., Design of sea walls allowing for wave overtopping, Technical Report No.EX 924, HR Wallingford, Oxon, (1980).
• [15] Ahrens, J.P. and Heimbaugh, M.S., Seawall overtopping model, Proceedings of the 21st International Conference on Coastal Engineering, 795-806, Costa de Sol-Malaga, (1988).
• [16] Juhl, J. and Sloth, P., Wave overtopping of breakwaters under oblique waves, Proceedings of the 24th International Conference on Coastal Engineering, 1182-1196, Kobe,(1994).
• [17] van der Meer, J.W. and Janssen, W., Wave run-up and wave overtopping at dikes, in Kobayashi and Demirbilek, Wave Forces on Inclined and Vertical Wall Structures, ASCE Publishing, 1-27, Rosewood, USA, (1995).
• [18] Schüttrumpf, H.F., Wellenüberlaufströmung bei Seedeichen - Experimentelle und theoretische Untersuchungen, Ph.D. Thesis, Leichtweiss-Institut für Wasserbau, TU Braunschweig, Germany,(2001).
• [19] Aminti, P. and Franco, L., Wave overtopping on rubble mound breakwaters, Proceedings of the 21st International Conference on Coastal Engineering, 770-781, Costa de Sol-Malaga,(1988).
• [20] Bradbury, A.P., Allsop, N.W. and Stephens, R.V., Hydraulic performance of breakwater crown walls, Technical Report No. 146, HR Wallingford, Oxon, (1988).
• [21] Pedersen, J. and Burcharth, H.F., Wave forces on crown walls, Proceedings of the 23rd International Conference on Coastal Engineering, 1489-1502, Venice,(1992).
• [22] Kofoed, J.P., Wave overtopping of marine structures - Utilization of wave energy, Ph.D. Thesis, Aalborg University, Denmark, (2002).
• [23] Pullen, T., Allsop, N.W.H., Bruce, T., Kortenhaus, A., Schüttrumpf, H. and van der Meer, J.W., EuroTOP: Wave overtopping of sea defences and related structures: Assessment manual, Boyens-Medien GmbH, Holstein, Germany, (2007).
• [24] Victor, L. and Troch, P., Wave overtopping at smooth impermeable steep slopes with low crest freeboards, Journal of Waterway, Port, Coastal and Ocean Engineering, 138, 5, 372-385, (2012).
• [25] van der Meer, J.W. and Bruce, T., New physical insights and design formulae on wave overtopping at sloping and vertical structures, Journal of Waterway, Port, Coastal and Ocean Engineering, ASCE, 140, 6, 1-18,(2014).
• [26] van der Meer, J.W., Allsop, N.W.H., Bruce, T., De Rouck, J., Kortenhaus, A., Pullen, T., Shüttrumpf, H., Troch, P. and Zanuttigh, B., EurOtop 2016: Manual on wave overtopping of sea defences and structures, (2016). www.overtopping-manual.com (14.12.2016).
• [27] Akgul, M.A., Design of a floating breakwater - wave energy converter hybrid, Ph.D. Thesis, ITU Institute of Science and Technology, Istanbul, (2014).
• [28] Schüttrumpf, H. and Oumeraci, H., Layer thicknesses and velocities of wave overtopping flow at seadikes, Coastal Engineering, 52, 473-495, (2005).