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船用螺旋桨水动力、空化和低噪声集成设计

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该文以开源软件OpenProp为基础,集成螺旋桨无空化噪声理论公式、空化噪声估算经验公式和新Burrill图谱,构建了船用桨水动力、空化和低噪声集成设计软件OpenProp+.OpenProp+的核心功能包括:完成桨叶几何设计并可信预报敞水性能曲线;判断桨叶有无空化产生,量化并确定空化范围,输出无空化工况的声压谱源级与中纵剖面声指向性图,估算空化噪声谱源级.当设计桨叶时,先确定相对最优的叶片数、直径和转速等总体参数,再优选叶型参数,设计考虑具体包括确定弦长分布规律、应用大侧斜设计要素、适当增加0.70R~0.95R(R为桨叶半径)叶截面最大厚度.桨叶最佳侧斜角临界值位于侧斜度50.0%~70.0%,设计初值可取60.0%.OpenProp+一体化设计效果由低噪声5叶桨设计给予检验,反馈良好,可直接服务于船用桨工程设计.
Integrated design of ship propellers considering hydrodynamics,cavitation,and low noise
[Objective]Designing ship propellers is a comprehensive engineering task that synergistically considers hydrodynamics,cavitation,vibration,and noise performance.To address the limitations of current design guidance cases and existing open design software,an integrated software called OpenProp+was developed.This application is designed to facilitate advancements in marine propeller design by incorporating theoretical formulas for noncavitation noise,empirical formulas for cavitation noise estimation,and the new Burrill diagram into the open-source software,OpenProp+.[Methods]The process of blade geometry design begins with determining the number of blades based on design requirements and empirical knowledge.The diameter is determined by the maximum power density limit and the optimal speed that meets the main engine's speed constraint,while the rotational speed is established according to the relative optimal efficiency.The three essential parameters for 3D blade section optimization along the radial direction are accomplished,including determining chord length distribution,applying a highly skewed angle,and suitably increasing the maximum thickness of the blade section from 0.70R to 0.95R.Notably,the chord length distribution should differ between five-blade and seven-blade propellers.The optimal skew value for the critical blade lies between 50.0%and 70.0%,with an initial recommended value of 60.0%.Appropriately increasing the tip thickness and its rake enhances anti-cavitation performance.Following design and optimization,performance prediction involves utilizing theoretical formulas of the propeller's free sound field by National Advisory Committee for Aeronoutics(NACA)to predict the source level of the sound pressure spectrum under noncavitation conditions and to illustrate its longitudinal acoustic direction diagram at discrete line spectrums.Factors such as ship speed,propeller rotating speed,diameter,blade numbers,thrust,and torque contributions to sound pressure are integrated into these formulas.The new Burrill spectrum can subsequently be employed to ascertain the presence of cavitation,estimate its range if it does exist,and qualitatively measure its noise performance under specific operating conditions.Finally,the Brown empirical formula estimates the propeller cavitation noise spectrum,while the Fraser empirical formula and International Council for the Exploration of the Sea(ICES)standard are used to quantitatively evaluate noise performance levels.[Results]The effectiveness of the integrated design software,OpenProp+,was validated through the design and performance prediction of a low-noise five-blade propeller,which yielded positive feedback.Within the full operating range,the open water performance curve of the designed blade almost coincided with the measured values of the original blade.Even on the off-design operating condition farthest from the designed advance ratio,the deviation between the thrust coefficient and torque coefficient compared to their measured value was only 4.65%.Considering the true ship wake flow distribution,the design point efficiency decreased by about 4%and the anti-cavitation margin decreased by about 12%.This indicated that the design program could effectively design the blades and reasonably predict their hydrodynamic and cavitation performance.[Conclusions]OpenProp+not only reliably predicts the open-water performance of existing propellers but also designs new propellers and accurately forecasts their open-water performance.It can determine the presence of cavitation,quantify its range if present,predict the noncavitation noise source level,and estimate the cavitation noise spectrum source level.Thus,OpenProp+and the complete design chart incorporated in the software can directly aid in the engineering application of ship propeller design.

propeller designhydrodynamiccavitationlow noiseOpenProp

杨琼方、黄修长、李晔

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海军工程大学动力工程学院,武汉 430033

上海交通大学机械与动力工程学院,上海 200240

上海交通大学船舶海洋与建筑工程学院,上海 200240

螺旋桨设计 水动力 空化 低噪声 OpenProp

2024

清华大学学报(自然科学版)
清华大学

清华大学学报(自然科学版)

CSTPCD北大核心
影响因子:0.586
ISSN:1000-0054
年,卷(期):2024.64(1)
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