Statistical Validation of a High-speed Catamaran in Irregular Waves

The paper presents an improved statistical validation method for irregular wave simulations, with application to the Delft catamaran at Fr=0.425 and (scaled) sea state 5. The procedure is based on non-overlapping and moving block bootstrap methods with optimal block size for primary variables (values from time series of wave elevation, heave, pitch motions, vertical acceleration of bridge and vertical velocity of flight deck), including validation values and intervals for EV, SD, mode, and quantiles. Comparison with autocovariance analysis is provided for EV and SD. Secondary variables (mean-crossing wave height of wave elevation, heave, pitch, acceleration and velocity) are validated applying the bootstrap method to EV, SD, mode, and quantiles. Validation values based on bootstrap methods are evaluated in terms of the median. Bootstrap methods overcome the limitations of the autocovariance analysis in evaluating confidence intervals for mode, quantiles and secondary variables in general. Compared to earlier studies, non-overlapping and moving block bootstrap methods provide smaller validation uncertainties by 6%. SD uncertainty is reduced by 11%. The average error for primary variables is 5.4%, with an average validation uncertainty equal to 28%, whereas the error for secondary variables is 19%, with an average validation uncertainty equal to 35% (errors and uncertainties are normalized with 2SD). New EFD data will be included in the final paper using a newly designed mount for force measurements, overcoming one of the limitations of earlier work. CFD simulations with a larger number of inlet wave components will be also included in the final work.