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Item type:Publication, Access status: with files , Partitioned simulation of the acoustic behavior of flexible marine propellers using finite and boundary elementsIn the last years, classification societies have announced several specifications regarding the limitation of the noise level of ships. Accordingly, the prediction of the acoustic signature of cavitating propellers, which are the main source for noise generation, has attracted a lot of interest. For an accurate numerical simulation of the underlying physics, the deformation of the propeller has to be taken into account, which results in a fluid-structure interaction (FSI) problem. In order to utilize different discretization methods for the individual sub-problems, we apply a partitioned solution approach. This makes it possible to use a finite element solver for the structural problem, while a boundary element solver is used for the fluid problem. From the solution of the FSI problem, the acoustic pressure in the far field is obtained using the Ffowcs William-Hawking equation.Publicationtype: Conference Paper62 133 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A partitioned solution approach for the simulation of dynamic behaviour and acoustic signature of flexible cavitating marine propellers(2020-02-01); ; ; Upcoming legislative developments and modern propeller designs call for numerical methods which are able to assess the complex interaction of the propeller's hydrodynamic and structural dynamic behaviour as well as the resulting influence on the acoustic signature. In this work, the problem is engaged making use of a partitioned, strongly coupled solution approach, thus enabling the usage of specialized solvers for each domain. On the fluid side, a boundary-element-method is applied while on the structural side a finite element method is employed. Information transfer between each subproblem is handled by a separate coupling tool. The acoustic evaluation is performed by means of a Ffowcs Williams-Hawkings equation based technique. In the present paper, the main focus is to establish the method's capability to simulate the interaction of all fields and its' physical consistency. The results show that an external excitation of the blade can be captured in the resulting acoustic spectrum.Publicationtype: Journal Article133 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A partitioned solution approach for the simulation of the dynamic behaviour of flexible marine propellers(2020-01-02); ; ; Modern designs of ship-propellers make use of novel materials such as composites, which may show a much lower stiffness than classical material. In order to accurately predict the hydrodynamic characteristics of these propellers in real operating conditions, the structural deformation must be accounted for, which leads to a fluid-structure interaction problem. In the present paper, a partitioned solution approach for such a strongly coupled two-field problem is presented. Owing to the separate modelling of the fluid and the structural problem in such approaches, specialised numerical methods can be applied on either side. Thanks to their superior convergence properties, we use high-order finite elements to discretise the structural problem. On the fluid side, a boundary element method, which is specifically designed to simulate the hydrodynamic behaviour of ship propellers is employed. In order to stabilise the solution procedure, different coupling algorithms and convergence acceleration methods are investigated.Publicationtype: Journal Article76 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 261 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Evaluation of Underwater Sound Propagation of a Catamaran with Cavitating Propellers(National Research Council of Italy, Institute of Marine Engineering (CNR-INM), 2019); ; ; The present article deals with the prediction of the underwater noise induced by ship propellers under consideration of sheet cavitation on the propeller blades. The calculation method is a hybrid approach combining a boundary element calculation method with the Ffowcs-Williams Hawkings equation. The capabilities of the method are demonstrated by simulating multiple operation states of the Newcastle University’s catamaran research vessel, the “Princess Royal”. The numeric results are compared to full-scale measurements.Publicationtype: Conference Paper108