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

Year 2015, Volume: 1 Issue: 2, 69 - 88, 01.12.2015

Cihad Delen Şakir Bal

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

References

• Coleman, H., W., & Steele, W., G., (2009). Experimentation, Validation, and Uncertainty Analysis for Engineers. 3th press, John Wiley & Sons, Inc., New York, NY.
• ASME, (2005). Test Uncertainty. American Society of Mechanical Engineers, New York.
• Bal, S., & Güner, M., (2011). Handbook of Naval Engineering. In “Chapter 4” (ed. Yılmaz T.), 2nd press.
• Bal, S., (2008). Performance Prediction of Surface Piercing Bodies in Numerical Towing Tank, International Journal of Offshore and Polar Engineering, 18(2): 106-111.
• Bal, S., (2008). Prediction of Wave Pattern and Wave Resistance of Surface Piercing Bodies by a Boundary Element Method, International Journal for Numerical Methods in Fluids, 56(3): 305-329.
• ITTC, (2002). Uncertainty Analysis, Example for Resistance Test. ITTC Recommended Procedures and Guidelines, Procedure7.5-02-02-02, Revision 01.
• ITTC, (2008). Guide to the Expression of Uncertainty in Experimental Hydrodynamics. ITTC Recommended Procedures and Guidelines, Procedure7.5-02-01-01, Revision 01.
• ITTC, (2014). General Guidelines for Uncertainty Analysis in Resistance Test. ITTC Procedure7.5- 02-02-02. Benedict, Measurement, Electro-Technol., p.51. Uncertainty in Delen, C., (2015). Uncertainty Analysis of Experimental Ship Resistance Tests, MSc Thesis, Istanbul Technical University, TURKEY (In Turkish).
• ITTC, (2002a). Ship Models. 23rdInternational Towing Recommended Procedure 7.5-01-01-1, Rev.01. Venice, ITTC and Guidelines, ITTC, Recommended Procedure7.5-02-02-01, Revision 01. ITTC Procedures and Guidelines, ITTC, 2014. Resistance Committee Report, Proceedings of 27thInternational Towing Tank Conference.
• ITTC, (2014a). Example for Uncertainty Analysis of Resistance Tests in Towing Tank, ITTC Procedure7.5-02-02-02.1.
• ITTC, (2014b). Practical Guide for Uncertainty Analysis of Resistance Measurement in Routine Tests, ITTC Procedure7.5-02-02-02.2.
• URL-1, Ship Form: Kriso Container Ship, KCS, (2015)
• https://www.nmri.go.jp/institutes/fluid_performanc e_evaluation/cfd_rd/cfdws05/Detail/KCS/kcs_g&c .html
• ITTC, (2008). Model Manufacture: Ship Models. ITTC Recommended Procedures and Guidelines, Procedure7.5-01-01-01.
• Goren, O., Danisman, D., B., (2002). Uncertainty Analysis of Model Resistance Test on Asphalt Tanker. Report No: 01.01/1. ITU Ata Nutku Ship Model Testing Laboratory (In Turkish).
• Simonsen, C., D., Otzen, J., F., Joncquez, S., Stern, F., (2013). EFD and CFD for KCS heaving and pitching in regular head waves. J. Mar. Sci. Technol., 18 (4): 435–459.
• Hino, T., (ed.) (2005). Proceedings of CFD Workshop Tokyo 2005. NMRI Report 2005, Tokyo, Japan.
• Bugalski & Hoffman P., 2011. Numerical Simulation of the Self-Propulsion Model Tests, 2nd Propulsors, Hamburg, Germany. on Marine
• Delen, C., Bal, S., 2015. Uncertainty Analysis of Resistance Tests in Ata Nutku Ship Model Testing Laboratory of Istanbul Technical University, 16th International Congress of the International Maritime Association of the Mediterranean, IMAM 2015, Pula, Croatia.