Ship underwater radiation noise assessment method

Abstract

The invention provides a ship underwater radiation noise assessment method. The method comprises the following steps: 1, inputting ship length, equipment type selection and total number of ship conceptual schemes, and equipment to ship bow distance; 2, identifying the exciting force of the mass center position of the equipment; 3, calculating a far-field underwater radiation noise sound source level and a frequency band sound source level of single-machine equipment of the ship; 4, calculating the total sound level of each point from the bow to the stern at the transverse a-meter position of the ship, drawing a characteristic curve of longitudinal distribution of sound pressure along the ship body as a passing characteristic curve of the ship, and determining the equivalent sound center ofthe ship; 5, estimating an underwater radiation noise source level, a frequency band sound source level and a sound pressure spectrum source level of the ship; and 6, comparing the parameters obtained in the step 5 with a design demand limit value to obtain a ship underwater radiation noise index argumentation and evaluation result. The far-field sound pressure value of the ship under the navigation working condition can be estimated according to the ship concept scheme at the demonstration stage, and demonstration evaluation is carried out on the far-field sound pressure value according to the demand limit value.

Description

technical field [0001] The invention relates to a ship vibration and noise reduction technology, in particular to an underwater radiation noise evaluation method. Background technique [0002] The underwater radiated noise index of ships is mainly used to describe the comprehensive effect of ship vibration and noise reduction measures, and to measure the distance of ships detected by passive sonar. For example, when the total sound level of underwater radiated noise is reduced from 150 decibels to 140 decibels, considering the full-band detection of sonar, the distance of ships detected by passive sonar detection will be shortened to 23% of the original detection distance. [0003] The underwater radiated noise index of a ship is usually evaluated and inspected based on the far-field sound pressure excited by the ship in water. The so-called far field refers to the position at a certain distance from the ship and the ship can be regarded as a point. At present, there is no...

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Problems solved by technology

At present, there is no report on the research on the demonstration and evaluation method of underwater radiated noise of ships in the relevant literature or materials at home and abroad.

In the study of ship vibration and noise prediction methods, although there are some mature methods, such as finite element method, boundary element method and statistical energy method, etc., which provide a theoretical basis for the prediction and analysis of ship vibration and noise performance (Wang Xu Zhangming, Wang Yu, Hua Hong magnitude, modeling of ship structure and FEM / BEM calculation of underwater vibration and radiated noise, Ship Mechanics, Vol. In the forecast analysis, it is necessary to obtain parameters such as structural drawings and equipment layout of the analysis pair

However, in the demonstration stage, the concept plan of the ship is relatively rough, with only parameters such as tonnage, overall size and preliminary equipment selection, and it is impossible to carry out the demonstration and evaluation of the ship's underwater radiated noise index according to the existing methods

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