Açik Deni̇z Rüzgar Enerji̇si̇ Türbi̇nleri̇ Teki̇l Kazik Temelleri̇ni̇n Çevresi̇ndeki̇ Boşluk Suyu Basinci Geli̇şi̇mi̇

Abstract

ÖZETAçık deniz rüzgar türbin tasarımında yaygın olarak kullanılan geniş çaplı tekil kazıklar ağır rüzgar ve dalga yüküne maruz kalırlar. Söz konusu temel sistemlerinin davranışının incelenmesine ve güvenlikli tasarım yöntemlerinin geliştirilmesine ihtiyaç bulunmaktadır. Bu amaçla, geniş çaplı tekil kazık ile tasarlanan türbin temel sisteminin davranışı sonlu elemanlar yöntemi ile incelenmiştir. Zemin elemanları için iki fazlı ve üç boyutlu u20p8 olarak isimlendirilen sonlu elemanlar geliştirilmiştir. Böylelikle, nümerik analizler boyunca çalışma kapsamında odaklanılmış olan, kazığın çevresindeki zeminde boşluk suyu basıncı gelişiminin elde edilmesi mümkün olabilmiştir. Zemin hipoplastik malzeme modeli ile modellenmiştir. Analiz sonuçları, açık deniz yük koşullarında kazık çevresinde önemli derecede aşırı boşluk suyu basıncı gelişiminin kazık başı deplasmanlarını oldukça etkilediğini göstermiştir. Literatürde yer alan mevcut yöntemlerin geniş çaplı kazığın deplasman tahmininde yetersiz kaldığı bulgulanmıştır. Sonrasında, kazık çapı-zemin geçirimliliğine dayanan parametrik analizler yapılmıştır. Analizler sonucu aşırı boşluk suyu basıncı birikim potansiyeline bağlı, temel tasarımında kullanılabilecek, karşılıklı etkileşim diyagramı sunulmuştur.Anahtar kelimeler: Açık deniz rüzgar enerjisi türbinleri, tekil kazık temel, tekrarlı yük, hipoplastik malzeme modeli, iki fazlı model, nümerik analiz, aşırı boşluk suyu basıncı PORE WATER PRESSURE DEVELOPMENT AROUND THE MONOPILE FOUNDATIONS OF OFFSHORE WIND ENERGY CONVERTERS ABSTRACTOffshore wind energy converters (OWECs) require specific foundations due to special loading conditions. Large diameter monopiles are widely proposed for OWECs. The behavior of large diameter monopiles under cyclic lateral loads was investigated in this study by means of numerical simulation with finite element method. Special focus is given to the pore water pressure accumulation around the monopile. For this purpose a fully coupled two-phase finite element (u20p8) is developed. A hypoplastic constitutive model for the saturated sand soil is used in the numerical analyses. The results revealed that, pile head displacement is strongly dependent on excess pore water pressure (EPWP) accumulation around the monopile. Subsequently, pile diameter-hydraulic conductivity interaction diagram was derived with a parametric study to estimate the pore water pressure accumulation potential. The proposed interaction diagram enables a preliminary design tool of monopiles for offshore wind energy converters in saturated sand soils.

GIS-based floating offshore wind turbine installation site selection using fuzzy analytic hierarchy process in northeast Aegean Sea

“…For Crete, the GIS method was also used [21] to identify sustainable offshore windfarm siting with respect to ecological and economical resources. The Aegean Sea coast was studied [3] using a GISbased Fuzzy Analytic Hierarchy Process (F-AHP) for the Gökçeada and Bozcaada Regions for suitable fixed offshore wind farms. Erkurtulmus [24] conducted GIS based site selection for floating offshore wind turbines and examined their effects on motion outcomes and performance on the Aegean Sea coast.…”

“…Some others have been carried out based on wind speed. For the establishment of offshore wind power plants in the Aegean Sea, Çanakkale, Gökçeada, and Bozcaada were comparatively categorized by using the F-AHP and GIS methods together [3]. In another study [32], an AHP method was applied for Northwest Türkiye.…”

“…In this study, distance to fault lines was evaluated based on data obtained from Kandilli Observatory [60]. In different studies in the literature, it has been argued that the distance of similar installations to fault lines should be at least 2,000 m [3]. In this study, areas 3,000 m distant from fault lines were chosen as the most suitable ones.…”

“…Considering the current problem of global warming, the environmental harms and exhaustibility of fossil fuels and increasing energy demands encourage a shift towards renewable resources for electricity generation [1,2]. Forms of renewable energy, which can be listed as solar, hydro, wind, current, tide, and wave energy, not only help protect employment but also contribute to increasing it 2 [3]. Due to its endless energy potential and continuity, wind energy is frequently preferred worldwide as a renewable energy resource for electricity generation.…”