Validation of Quasi-steady Model Propulsion Tests

During a measurement run of a quasi-steady model propulsion test, the loading (RPM) of the propeller(s) is gradually changed at a constant carriage and model speed. By this method it is possible to efficiently capture loading effects for each speed. Already after the first measurement run complete and accurate extrapolation to full scale can be made. Loading effects are alsoimportant in case of mutual interactions between various propulsor components, e.g. a hybrid propulsion system.MARIN wants to introduce the quasi-steady test technique in daily practice to replace gradually the conventional steady approach. Therefore a validation programme was started to compare resultsobtained with both techniques for five different models. Both single and twin propeller and pod ships are have been tested ranging from a cargo to a cruise ship, using identical setups andconditions for both methods. Several details of the experimental procedure are discussed. The influence of the regression analysis and numerical model was investigated. Results of the validation programme show a good agreement between the conventional and quasi-steady propulsion test procedures.