Alizadeh Valiollah, Abbaspour Madjid, Mohseni Arasteh Afshin, Lari Kamran, Torabi Azad Masoud
Department of Physical Oceanography, Faculty of Marine Science and Technology, Islamic Azad University, North Tehran Branch, Tehran, Iran.
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
Heliyon. 2024 Apr 16;10(8):e29632. doi: 10.1016/j.heliyon.2024.e29632. eCollection 2024 Apr 30.
Ship noise emission has many environmental impacts. Recognizing noise-generating source and investigating noise reduction techniques is the first step in elimination or reduction of these harmful effects. Studies show that ship propeller is one of the main sources of ship noise emission. Ducted propeller is one of the well-known solutions for noise reduction. In this paper, results of numerical solution for governing mathematical equations of noise emission in far field is presented and sound pressure level is calculated using Ffowcs Williams and Hawkings (FWH) equations. Numerical solution is validated by valid research resources. Propeller noise emission is also calculated by experimental measurements and filtering ambient noise frequencies. Finally, a comparison has been made between numerical solution and experimental results and the effect of duct on noise reduction is calculated. The measured SPL emitted from the propeller in CFD approach (solving the FWH) shows 28% reduction for ducted propeller in comparison with the propeller without the duct. In experimental approach (after removing the ambient noise) shows 37% reduction for ducted propeller in comparison with the propeller without the duct.
船舶噪声排放具有诸多环境影响。识别噪声产生源并研究降噪技术是消除或降低这些有害影响的第一步。研究表明，船舶螺旋桨是船舶噪声排放的主要来源之一。导管螺旋桨是一种广为人知的降噪解决方案。本文给出了远场噪声排放控制数学方程的数值解结果，并使用Ffowcs Williams和Hawkings（FWH）方程计算了声压级。数值解通过有效的研究资源进行了验证。螺旋桨噪声排放也通过实验测量和过滤环境噪声频率来计算。最后，对数值解和实验结果进行了比较，并计算了导管对降噪的影响。在CFD方法（求解FWH）中，螺旋桨发出的测量声压级表明，与无导管螺旋桨相比，导管螺旋桨的噪声降低了28%。在实验方法中（去除环境噪声后），与无导管螺旋桨相比，导管螺旋桨的噪声降低了37%。
