Experimental analysis of self-propelled characteristics with uncertainty analysis of ONR tumblehome hull

In this paper, the self-propelled characteristics of the benchmark ONRT hull were studied experimentally at both Froude numbers, Fr = 0.20 and Fr = 0.30. The assessments were conducted under free-running conditions using a fully appended Office of Naval Research Tumblehome (ONRT), model 5613, scaled at 48.9, a customary proportion in academic research. To demonstrate the reliability of self-propulsion experiments conducted at the Istanbul Technical University, Ata Nutku Ship Model Testing Laboratory (ITU-AN), an uncertainty analysis method was applied to the ONRT results. The self-propulsion points from the studies in literature at both Fr = 0.20 and Fr = 0.30, were compared with the present test results. Based on the analysis results at self-propulsion points, it was noted that there was a high level of both intra-laboratory repeatability and inter-laboratory reproducibility characteristics. Through repeated tests, it was discerned that the uncertainties impacting essential parameters were, in descending magnitude, thrust, torque, and rotational rate. Consequently, this investigation enhances the precision and reliability of results by presenting the thrust and torque characteristics of the ONRT hull form, along with associated uncertainties for these Fr numbers.