The traditional way of conducting and evaluating ship speed trials is very costly and involved and the results are not very trustworthy. The reason for this situation is that the logic and the methods behind the whole procedure are not very clear in the opinion of Prof. Michael Schmiechen in Berlin.
Consequently he has prepared a proposal for a clear-cut procedure as a contribution to the discussion on the current ISO/WD 15016. His approach is based on the theory of rational conflict resolution, accordingly requiring only a minimum of simple conventions on the power function in the behind condititon and on the current velocity and requiring no reference to model test results.
In a number of examples he has shown that the few parameters of the functions of powers delivered by ship propellers in the behind conditions can be identified together with those of the current velocities from the usual minimum of test runs using systems identification techniques. Similarly the parameters of the functions of powers required due to water and wind resistance have been identified in the most recent examples from the same sets of data.
The work is a by-product of experience he gained during applications of his rational theory of ship hull-propeller interaction in full scale testing of the German research vessel METEOR and the Blohm+Voss experimental SES CORSAIR.
More information: Prof. Michael Schmiechen, Berlin