Determination of ice-induced anti-torque of propeller

Abstract

Object and purpose of research. This paper discusses the methods for determination of propeller anti-torque in ice milling conditions. The purpose of the study was to investigate existing methods for propeller anti-torque determination, analyse their respective pros and cons and to trace out the paths of further studies towards a satisfactory description of propeller anti-torque. Materials and methods. This study relies on previous publications and experimental ice milling data from both laboratory tests and field measurements, as well as on full-scale measurement data obtained on propulsion shafts of real icebreakers and ice-going ships. Main results. Currently, there is a wide variety of methods for obtaining anti-torque data: regulatory, theoretical, model testing and full-scale measurements on ship shafting. Analysis of the regulations given in the recommendations of various class societies has shown considerable drawbacks in the calculation formulae used in them. This paper proves that the most viable method for propeller anti-torque determination is its reconstruction as per the results of full-scale measurements on shaft line. Conclusion. Current methods for determination of anti-torque do not describe this phenomenon exhaustively. The most promising solution here would be to perform full-scale trials and analyse their results.