Blade Section Profile Array Lifting Surface Design Method for Marine Screw Propeller Blade

Energy efficiency has become more important in every industry and daily life. Designing and building a more efficient marine vehicle can lead to lower fuel consumption and a longer lifetime for the components of the vehicle. Erosion caused by cavitation reduces the service life of the propeller and the related components in the propulsion and maneuvering system. Reducing cavitation leads to a longer life for these components. This paper aims to explain and investigate propeller blade cup as a cavitation reduction method for marine propellers. A cavitating no-cup propeller is created and analyzed then the cupped version of this propeller is generated and analyzed to compare with the no-cup propeller. Cavitation results of these propellers are investigated. In addition, the thrust, torque, and efficiency of the propellers are compared.

Section: Cavitation Reduction By Cup Methods No Cupped and Cupped Propeller Comparisonmentioning

confidence: 99%

Blade Cup Method for Cavitation Reduction in Marine Propellers

Şamşul

2021

“…The lifting surface method for open-water analysis is a classic method similar to that described in [20]. The initial step of the calculations provides a discrete representation of the propeller geometry.…”

Section: Lifting Surface Analysismentioning

confidence: 99%

Analysis of Model-Scale Open-Water Test Uncertainty

Król¹

2022

Self Cite

Within the frame of CTO’s standard procedure, a propeller open-water test is preceded by a reference measurement, which is taken for a reference propeller model (P356). The results of these measurements are assembled to conduct an open-water test uncertainty analysis. Additional material was gathered from open-water tests that were conducted throughout several research projects on the CP469 model, which is a model of the Nawigator XXI propeller. The latter is a controllable pitch propeller; its pitch was reset before each test repetition. Known procedures for the determination of the open-water test uncertainty do not allow one to extract the manufacture impact directly, without building many models. This factor was addressed with the use of lifting surface calculations. Under certain additional assumptions, these calculations were performed for 100 generic versions of each propeller’s geometry, which were generated by random deviations from the theoretical data within the limits of allowed tolerances. The results of the conducted analyses made it possible to extract separate factors, which were connected to the test’s repeatability, measurement bias and geometry tolerance.

“…Ships are a contributor to greenhouse gas (GHG) emissions [1], and in recent years, increasing pressure has been placed on the marine industry to decrease GHG emissions through regulatory legislation. IMO (International Maritime Organization) indicated that efficiency improvements could be achieved through operational [2] and technological methods, as these could increase overall performance and decrease fuel consumption [3][4][5][6][7][8][9][10]. Temporary roughness, which refers to temporal changes in the hull and propeller surface roughness, is caused by fouling organisms during a period of service [8].…”

Section: Introductionmentioning

confidence: 99%

Effects of Propeller Fouling on the Hydrodynamic Performance of a Marine Propeller

Zinati,

Ketabdari,

Zeraatgar

2023

Propeller performance is typically considered under clean conditions, despite the fact that fouling is an inevitable phenomenon for propellers. The main objective of this study is to investigate the effects of roughness due to fouling on the performance of a propeller using a CFD simulation in conjunction with the roughness function model. A simulation of a clean propeller is verified for a five-blade propeller model using existing experimental results. A roughness function model is then suggested based on existing measured roughness data. The simulations are extended for the same propeller under varying severities of roughness. Initially, it is concluded that KT and ηo gradually decrease with increasing fouling roughness, while KQ increases, compared to smooth propeller. For instance, at J=1.2 for medium calcareous fouling, KT is reduced by about 26%, KQ increases by about 7.0%, and ηo decreases by 30.9%. In addition, for the rough propeller, the extra power required is defined as the specific sea margin (SSM) to compensate for the power loss. A slight roughness causes a large decrease in ηo. A propeller painted with foul-release paint and an unpainted propeller are found to require 2.7% SSM and 57.8% SSM over four years of service, respectively. Finally, the use of foul-release paints for propeller painting is strongly advised.