The use of System Identification Techniques to Measure the Ship Resistance, Powering and Maneuvering Coefficients of the Exxon Philadelphia and a Submarine from Simple Trials During a Routine Voyage

The ship modeling testing community is well aware of the difficulties and uncertainties that exist in predicting ship performance from scaled model tests because of the inability to satisfy the condition that the model be tested at the same Reynolds’ number at which the ship operates. As a result, the hydrodynamic coefficients measured on the model are not the same as those of the ship at this scale effect must be corrected for in order to produce realistic and reliable prediction of ship performance. Many methods of correcting for scale effect involving theoretical and experimental studies have been developed over the years to help improve predictions, but we presently are not satisfied and strive to improve out techniques.