Uncertainty Analysis of Resistance Tests in Ata Nutku Ship Model Testing Laboratory of Istanbul Technical University

Abstract

In this study, some systematical resistance tests, where were performed in Ata Nutku Ship Model Testing Laboratory of Istanbul Technical University (ITU), have been included in order to determine the uncertainties. Experiments which are conducted in the framework ofmathematical and physical rules for the solution of engineering problems,measurements, calculations include uncertainty. To question the reliability of the obtained values, the existing uncertainties should be expressed as quantities. The uncertainty of a measurement system is not known if the results do not carry a universal value. On the other hand, resistance is one of the most important parameters that should be considered in the process of ship design. Ship resistance during the design phase of a ship cannot be determined precisely and reliably due to the uncertainty resources in determining the resistance value that aretaken into account. This case may cause negative effects to provide the required specifications in the latter design steps. The uncertainty arising from the resistance test has been estimated and compared for a displacement type ship and high speed marine vehicles accordingto ITTC 2002 and ITTC 2014 regulations which are related to the uncertainty analysis methods. Also, the advantages and disadvantages of both ITTC uncertainty analysis methods have beendiscussed.Keywords: Measurement, bias & precision limit, displacement ship, KrisoContainer Ship (KCS), high speed marine vehicle.

Keywords

• precision limit, displacement ship, Kriso Container Ship (KCS), high speed marine vehicle

İstanbul Teknik Üniversitesi Ata Nutku Gemi Model Testi Laboratuvarında Direnç Testlerinin Belirsizlik Analizi

Abstract

Bu çalışmada, İstanbul Teknik Üniversitesi (İTÜ) Ata Nutu Gemi Model Laboratuvarında gerçekleştirilen model direnç deneylerinin belirsizliği incelenmiştir. Belirli fiziksel ve matematiksel yaklaşımlar ve varsayımlar altında gerçekleştirilen deneyler hem ölçüm sisteminin hem de çevresel şartların etkisi ile sonuçlar üzerinde belirsizlikler içermektedir. Deney sonucunda elde edilen değerin doğruluğu veya güvenilirliği mevcut belirsizliklerin incelenmesi ve sayısal olarak ifade edilmesiyle mümkündür. Eğer deney sonucunda elde edilen değerin belirsizliği tahmin edilmez ise bu değerin evrensel anlamda geçerliliği kısıtlıdır. Diğer taraftan, gemi direnci, gemi dizayn spirali içerisinde dikkat edilen en önemli parametrelerin başında gelmektedir. Eğer dizayn aşamasında gemi direnci değeri gerçeğe en yakın şekilde tahmin edilmez ise, bu durum sonraki dizayn aşamalarını da önemli ve olumsuz yönde etkileyebilecektir. Bu yüzden model testlerinde ve değerlerin analizi sırasında meydana gelebilecek muhtemel belirsizlik kaynakları incelenmelidir. Bu çalışmada, deplasman tipi gemi ve hızlı tekne modellerinin direnç testlerinde ortaya çıkan belirsizlikler ITTC 2002 ve ITTC 2014 belirsizlik analizi prosedürleri dikkate alınarak tahmin edilmiştir. Aynı zamanda, bu iki farklı yöntem karşılaştırılarak avantajlı ve dezavantajlı yönleri tartışılmıştır

Keywords

• Ölçme, eğilim & kesinlik limiti, deplasman gemisi, Kriso Konteynır Gemisi, hızlı tekne

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