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Showing 2 results for High Skew Propeller
Numerical analysis of the effect of geometric pitch on the radiated noise level of high skew propeller
Ehsan Yari,
Volume 20, Issue 44 (10-2024)
Abstract
The purpose of this article is the numerical hydro acoustic analysis of non-cavitating radiated noise in different geometric pitches using the computational fluid dynamics method. The geometric pitch of the propeller is one of the most important influencing parameters in the design of marine propellers, Therefore, in this article, a sample of the standard underwater propeller series with different number of blades and different geometric pitches has been used and the data related to the vorticity field and the radiated noise level have been extracted and studied. In this numerical analysis, the DES turbulence model has been used, which has solutions with acceptable accuracy in the noise subject with an average grid number, compared to the large eddies method. In order to increase the accuracy of the numerical data, the grid generated around the propeller in the areas of the leading edge, trailing edge, tips of the blades and in the region of the downstream, has been produced with a higher grid density. According to the obtained results, by increasing the geometric pitch angle of the propeller blade, the static pressure on the pressure side of the blade increases, and the vortices caused by the boss and hub become longer, and the amount of change in the sound pressure level in the axial direction at low frequencies is less than 5 dB, but at high frequencies it is oscillating and the changes are more noticeable. The highest amount of change in the sound pressure level in terms of pitch is in the direction perpendicular to the flow direction and reaches up to about 40 db.

Hydroacoustic and hydrodynamic optimization of a high skew marine propeller
Mohammad Reza Najafi,
Volume 21, Issue 46 (7-2025)
Abstract
One of the main sources of noise generation from marine vehicles is propellers. The noise generated by propellers can lead to identify by detection systems and have negative effects on marine ecosystems. Researchers have investigated various methods to reduce the noise of marine propellers. However, what is important in practice is the simultaneous reduction of noise with an increase in propeller efficiency, which has received less attention. In this paper, while investigating various geometric parameters in order to achieve an optimal noise-reduced propeller, the increase in propeller efficiency is also addressed. Numerical simulations have been conducted using computational fluid dynamics (CFD) based on the finite volume method and the STAR-CCM+ software. To validate the hydroacoustic and hydrodynamic simulations, a conventional propeller with available data was utilized. The results of this study indicate that the high-skew propeller, after the optimization process, under equal operating conditions, achieved a 1.95% increase in efficiency and a 5.3 dB reduction in noise at the first blade passing frequency compared to the conventional propeller
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