Reducing Engine-Induced Ship Noise at Source
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Beschreibung
Maritime transportation remains a cornerstone of global trade and commerce,
with ships serving as vital vessels for transporting goods and passengers
across the world’s oceans. However, the environmental impact of this
industry, particularly concerning underwater noise pollution, has received
increasing attention in recent years. Engine-induced ship and underwater
noise, arising from propulsion systems and onboard machinery, poses
significant challenges to marine ecosystems and marine life.
This thesis delves into the aspects of engine-induced structure-borne
noise aboard ships, aiming to improve existing analytical and numerical
prognosis and simulation methods for the characterization of noise sources,
i.e. combustion engines, propagation mechanisms, and resulting impacts
on the ship structure. The research focuses on cruise ships and associated
propulsion technologies, namely medium-speed four-stroke engines, to provide
a nuanced understanding of the noise generation and propagation process.
State-of-the-art calculation methods, i.e. mobility- and impedancebased
techniques, have shown to not meet the required accuracy, necessary
for a reliable design of ships. This work analyses these methods and possible
causes for deviations. Therefore, a detailed multibody simulation model
of a combustion engine is developed and validated with measurement data,
consisting of all relevant structural parts and considering their interactions,
for the description of the noise source. A detailed analysis of the engine
model reveals excitation properties, which are not considered in traditional
models up to now and sheds new light on the vibration properties of combustion
engines. For the modeling of noise propagation, existing transfer
function methods are used and extended from single-point to multi-point
applications, incorporating all degrees of freedom of the system. The received
noise impacts on ships are evaluated based on a generic model of an
engine foundation on a cruise ship double-bottom structure.
Ultimately, this doctoral thesis contributes to the body of knowledge
surrounding engine-induced ship noise by providing a comprehensive assessment
of its excitation, transmission, and recipience on the ship. The
research aims to improve structure-borne noise prediction methods for the
usage by development and research engineers in the field of ship noise, to
mitigate noise pollution and ensure the long-term health of our oceans.
Autor*in
Matthias Donderer
Themen in »Reducing Engine-Induced Ship Noise at Source«
Ship Noise Ship Engine Structural damping