Open AccessPrediction of propeller hydromechanics for a single-shafter
Author(s) -
O. Orlov
Publication year - 2021
Publication title -
trudy krylovskogo gosudarstvennogo naučnogo centra
Language(s) - English
Resource type - Journals
eISSN - 2618-8244
pISSN - 2542-2324
DOI - 10.24937/2542-2324-2021-1-395-65-78
Subject(s) - propeller , extrapolation , hull , thrust , marine engineering , scale (ratio) , full scale , test data , scaling , scale effects , propulsive efficiency , engineering , computer science , structural engineering , mathematics , statistics , mechanical engineering , physics , geometry , software engineering , quantum mechanics
Object and purpose of research. This paper discusses hydromechanics properties of propeller and their scaling laws. The purpose of this study was to analyse existing methods of scaling model test data through their comparison with full-scale test results, identify possible sources of considerable error that might be present in them, as well as update the method of model test data scaling taking into account hydrodmechanic interaction between propeller and hull in terms of their model data extrapolation to the full scale. Materials and methods. The paper discusses general relationships between hydromechanic parameters of hull and propeller, that arise, in their turn, from the fundamental laws of mechanics. These relationships were used to analyse interconnected laws governing the full-scale extrapolation of model test data for hull resistance, propeller thrust and propeller torque. Main results. The study identified some incorrect hypotheses in current scaling methods for hydrodynamics of propeller in behind-hull conditions, that might bring about considerable error in full-scale estimates of operational advance coefficient, thrust coefficient, efficiency and RPM. Conclusion. This paper suggests alternative techniques for determination of operational advance coefficient and other hydromechanics parameters of full-scale propeller, so as to obtain the estimates that take into account physical peculiarities of scale effect and also correlate with the results of full-scale trials.