Singing Propellers—Solutions and Case Histories

Fischer, Raymond

doi:10.5957/mt1.2008.45.4.221

Cited by 11 publications

(5 citation statements)

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“…If merchant vessels are not cavitating, the noise that can be identified are from the blade passage frequencies and, if present, due to flow-excited propeller blade vibrations ('propeller singing'). These tones may occur for wide range of frequencies depending on propeller size and shaft rotation rate: Fischer (2008) shows examples in which the frequency of singing varied between 180 and 1800 Hz. Carlton (2018) describes cavitation showing that it is an important source of shipping noise.…”

Section: Propeller Noisementioning

confidence: 99%

The present and future contribution of ships to the underwater soundscape

Possenti,

de Nooijer,

de Jong

et al. 2024

Front. Mar. Sci.

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Since the industrial revolution the ocean has become noisier. The global increase in shipping is one of the main contributors to this. In some regions, shipping contributed to an increase in ambient noise of several decibels, especially at low frequencies (10 to 100 Hz). Such an increase can have a substantial negative impact on fish, invertebrates, marine mammals and birds interfering with key life functions (e.g. foraging, mating, resting, etc.). Consequently, engineers are investigating ways to reduce the noise emitted by vessels when designing new ships. At the same time, since the industrial revolution (starting around 1760) greenhouse gas emissions have increased the atmospheric carbon dioxide fraction x(CO2) by more than 100 μmol mol-1. The ocean uptake of approximately one third of the emitted CO2 decreased the average global surface ocean pH from 8.21 to 8.10. This decrease is modifying sound propagation, especially sound absorption at the frequencies affected by shipping noise lower than 10 kHz, making the future ocean potentially noisier. There are also other climate change effects that may influence sound propagation. Sea surface warming might alter the depth of the deep sound speed channel, ice melting could locally decrease salinity and more frequent storms and higher wind speed alter the depth of the thermocline. In particular, modification of the sound speed profile can lead to the appearance of new ducts making specific depths noisier. In addition, ice melting and the increase in seawater temperature will open new shipping routes at the poles increasing anthropogenic noise in these regions. This review aims to discuss parameters that might change in the coming decades, focusing on the contribution of shipping, climate change and economic and technical developments to the future underwater soundscape in the ocean. Examples are given, contrasting the open ocean and the shallow seas. Apart from the changes in sound propagation, this review will also discuss the effects of water quality on ship-radiated noise with a focus on propeller cavitation noise.

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Section: Propeller Noisementioning

confidence: 99%

The present and future contribution of ships to the underwater soundscape

Possenti,

de Nooijer,

de Jong

et al. 2024

Front. Mar. Sci.

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“…The faster rotating and small propeller, the higher the singing frequency will be [8]. Since the propeller singing causes stress crack or structural failure of the blade, however, it should be prevented by anti-singing treatments such as an asymmetric trailingedge (for more information, refer to [9]). The most crucial source of underwater noise from a ship is cavitation, which is known to peak at 50-150Hz (at blade passing frequency and its harmonics) can be broadband up to 10kHz [10].…”

Section: Reviewmentioning

confidence: 99%

Towards Minimizing Underwater Noise from Ships

Lee¹

2017

OFOAJ

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“…Singing is a disturbing phenomenon on the propeller. Singing often occurs in propellers with high rotational speeds [1], as well as in propellers with wide and thin blade sizes [2]. Singing can increase airborne noise and underwater noise on ships.…”

Section: Introductionmentioning

confidence: 99%

“…Airborne noise can interfere the performance of ship crews, beside that underwater noise can increase the possibility of warships being detected by enemy devices [3] [4]. The cause of singing on the propeller is the resonance between the natural frequency of the propeller tip and vortex shedding on the trailing edge [2][3] [5] [6]. The most common way to deal with singing on a propeller is to sharpen the trailing edge [1].…”

Section: Introductionmentioning

confidence: 99%

“…The most common way to deal with singing on a propeller is to sharpen the trailing edge [1]. By sharpening the trailing edge, it is hoped that the separation point will be clearer, and the wake vortices and induced forces are lower than the blunt trailing edge [2]. In addition, sharpening the trailing edge can narrow the vortex street, so that the vortex shedding strength will decrease [7].…”

Section: Introductionmentioning

confidence: 99%

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Propeller Performance Analysis on The Modification of Trailing Edge Shape as Anti-Singing

Fikry

Ariana

Kusuma

2023

IOP Conf. Ser.: Earth Environ. Sci.

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Singing is one of the problems that occurs in the propeller. However, singing will not happen to every propeller. Singing occurs a lot in high-speed propellers and on propellers with wide and thin blade sizes. One of the ships that have high speed and wide propeller is fast patrol boat. To overcome this problem, modifying the trailing edge is one of the most commonly used methods. Sharpening the trailing edge is a way to reduce vortex shedding. However, modifying the trailing edge of the propeller will change the shape of the propeller, which can affect the performance of the propeller. Therefore, this study discussed about the effect of trailing edge modification as anti-singing on propeller performance. Propeller performance analysed with open water test simulation assisted by computational fluid dynamic based software. There are three sharpening model in this study, where the sharpening size in this study refers to Van Lammeren anti-singing design. The size of sharpening are 20 mm, 25 mm, and 30 mm, where 20 mm sharpening is the best modification to overcome singing according to flow analysis. The open water test simulation result shows that the modification of trailing edge as anti-singing can increase the average thrust coefficient 8.96%, average torque coefficient 7.88%, and average open water efficiency 1.29%.

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Singing Propellers—Solutions and Case Histories

Cited by 11 publications

References 0 publications

The present and future contribution of ships to the underwater soundscape

The present and future contribution of ships to the underwater soundscape

Towards Minimizing Underwater Noise from Ships

Propeller Performance Analysis on The Modification of Trailing Edge Shape as Anti-Singing

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