Evaluation is performed of the data used for T2015 test cases for the KCS captive added resistance σAR and ONRT free running course keeping/speed loss in head and oblique waves. For KCS calm water resistance, the individual facility N-order level testing uncertainty is UXi = 1%D and the multiple facility standard deviation based on three institutes using 2 model sizes (L = 7.3 and 6.1 m) is SD = 0.74%D, such that the individual facility MxN-order level testing uncertainty is UDi = 1.75%D. UXi was not reported for sinkage and trim; however, the SD = 4 and 7%D, respectively. For KCS head waves, the analysis was based on three institutes with model sizes L = 6.1, 3.2 and 2.7 m. For the 6.1 m model, FORCE provided UXi = 8, 4 and 4%D, respectively, for σAR and first harmonic heave z1/ζ1 and pitch θ1/ζ1k amplitudes, whereas for the 2.7 m model, FORCE/IIHR provided UXi = 7/18, 8/2 and 9/5%D, respectively. In consideration of the differences in model sizes and rigid vs. surge free mounts the agreement between the facilities is reasonable: for the primary variables, SD = 3, 20 and 10%D for z1/ζ1 and θ1/ζ1k amplitudes and σAR, respectively; and for secondary variable SD = 66%D for first harmonic resistance CT1. For KCS oblique waves, the data is only available from IIHR for tests in 2015 and 2016. The agreement is good, i.e., SD values are comparable to the corresponding values for head waves: for primary variables, SD = 6 and 63%D for z1/ζ1 and θ1/ζ1k amplitudes and σAR, respectively; and for secondary variable SD = 13%D for CT1. For ONRT self-propulsion and head and oblique waves, the data is only available from IIHR and only preliminary uncertainty analysis is available. The evaluation showed reasonably reliable data for both KCS and ONRT. However, clearly it is desirable to have data from more facilities including uncertainty analysis for assessment of facility biases, which will provide more robust data and uncertainty analysis for CFD validation.
Experimental Data for KCS Added Resistance and ONRT Free Running Course Keeping/Speed Loss in Head and Oblique Waves
Lect.Notes in Applied (formerly:Lect.Notes Appl.Mechan.)
2020-07-26
77 pages
Article/Chapter (Book)
Electronic Resource
English
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