Development of Advanced Quality Control System of Ship Performance Tests in Towing Tank

(Detection and Analysis of Higher-Order Uncertainties Originated from Model Propeller Accuracy)

Abstract

The appearance and propagation of uncertainties in propulsive performance tests in towing tank were investigated. A concept of higher-order uncertainty was introduced, and the idea was applied to the evaluation of uncertainties originated from the model propeller accuracies. A series of performance tests using five stock propellers were carried out, and the influences of manufacturing accuracy and deterioration due to the long-term operation were examined. The details of uncertainty propagations were analyzed, and the indirect propagation mechanisms of higher-order factors were clarified. The evaluated results show the possibility of violence on final result quality by inappropriate quality managements. Utilizing the established evaluation system, an advanced quality control procedure was proposed. By tracing the uncertainty propagations in opposite direction from the ordinary evaluation actions, proposed procedure enables us to feed back the demands on final results to the source factors