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Study The Effect of Geometric Parameter on Hydrodynamic and Hydroacoustic Performance Marine Propeller in Far Field by the Openwater Method
, M.Sc. Thesis Sharif University of Technology ; Seif, Mohammad Saeed (Supervisor) ; Mehdigholi, Hamid (Co-Supervisor)
Abstract
One of the most important noise produced by craft, is the propeller noise which must be identified and measured for many reasons, including military and engineering applications. Therefore, in the first step, the sources of noise emissions in the propeller are studied, and after describing the research background, the governing equations of this research are examined. Then, to validate, the DTMB 4119 propeller, which has hydrodynamic and hydroacoustic results, is used. In order to carry out the investigations, a B series propeller model is selected and compared with changing the parameters of the Rake, Skew, Pitch ratio and the number of blades for their hydrodynamic and hydroacoustic...
Reduce Contra Rotating Propeller (CRP)Noise Level By Improving Design Specifications
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Madjid (Supervisor) ; Shafii, Mohammad Behshad (Co-Supervisor)
Abstract
One of the biggest problems in improving the performance of submersible propellers is the acoustic standard in conventional propellers. Recently, new solutions in propellers geometry have been used to reduce non-cavitation noise. Designing CRP licenses is one of these methods. This research includes numerical analysis. Numerical analysis in this research solves RANS equations of flow and extraction of hydrodynamic parameters and impeller noise in Ansys software. The results of numerical hydrodynamic solution are validated by laboratory results.DTMB 4119 three-blade propeller is used for hydrodynamic and hydroacoustic validation. The solution of Lighthill equations by FW-H method is...
Analysis of noise behaviour for marine propellers under cavitating and non-cavitating conditions
, Article Ships and Offshore Structures ; 2015 ; 17445302 (ISSN) ; Seif, M. S ; Mehdigholi, H ; Yaakob, O ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
In this study, the hydrodynamics and noise behaviour of marine propellers are examined through finite volume method under various operational conditions. The hydrodynamics of these propellers are studied both numerically and experimentally, and the characteristic curves are produced. Sheet cavitation inception and development conditions are also considered in order to understand the impact of different rotational speeds on propeller noise. Ffowcs Williams and Hawkings equations are used to extract the total sound pressure levels under non-cavitating and sheet cavitating conditions. Finally, the impact of cavitation on increasing the propeller noise is thoroughly explored and the results are...
Analysis of noise behaviour for marine propellers under cavitating and non-cavitating conditions
, Article Ships and Offshore Structures ; Volume 12, Issue 1 , 2017 , Pages 1-8 ; 17445302 (ISSN) ; Seif, M. S ; Mehdigholi, H ; Yaakob, O ; Sharif University of Technology
Abstract
In this study, the hydrodynamics and noise behaviour of marine propellers are examined through finite volume method under various operational conditions. The hydrodynamics of these propellers are studied both numerically and experimentally, and the characteristic curves are produced. Sheet cavitation inception and development conditions are also considered in order to understand the impact of different rotational speeds on propeller noise. Ffowcs Williams and Hawkings equations are used to extract the total sound pressure levels under non-cavitating and sheet cavitating conditions. Finally, the impact of cavitation on increasing the propeller noise is thoroughly explored and the results are...
An experimental investigation of hydrodynamic performance, cavitation, and noise of a normal skew B-series marine propeller in the cavitation tunnel
, Article Ocean Engineering ; Volume 238 , 2021 ; 00298018 (ISSN) ; Razaghian, A. H ; Tootian, A ; Seif, M. S ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this paper, the hydrodynamic performance, cavitation inception, and acoustic performance of a 5-bladed B-series propeller are experimentally investigated in the Sharif University of Technology cavitation tunnel. For hydrodynamic performance, thrust, torque, and efficiency of the propeller model were measured in open water tests. In the cavitation study, in addition to blade cavitation, tip vortex cavitation was also observed, and the cavitation bucket diagram was extracted in different advance coefficients. Finally, for the acoustic analysis of the propeller, the emitted noise in the cavitation tunnel was recorded using two hydrophones according to the recommended procedures of the...
Investigating the effect of geometric parameters on hydrodynamic and hydro-acoustic performances of submerged propellers
, Article Applied Ocean Research ; Volume 114 , 2021 ; 01411187 (ISSN) ; Ebrahimi, A ; Zahedi, F ; Javanmardi, M. R ; Seif, M. S ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The hydro-acoustic analysis of submerged propellers is an important issue in marine industries, which is examined to reduce the vibrations and noise level of vessels alongside reducing fuel consumption and improving hydrodynamic efficiency. B-series propellers are common propellers whose hydrodynamic and acoustic investigation through applying suitable rake, and skew angle can offer proper results to designers for enhancing the hydrodynamic performance and reducing noise. In this study, a model of the five-bladed B-series propeller with the normal skew angle is chosen. The effects of geometric parameters, including the rake angle, skew angle, geometric pitch ratio, and the number of blades...