Wideband spectrum noise forecasting method in cavitation inception state of combined propeller

A thruster, combined technology, applied in the field of prediction of wide-band spectral noise

CN103714246AActive Publication Date: 2014-04-09NAVAL UNIV OF ENG PLA
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2014-04-09

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Abstract

The invention discloses a wideband spectrum noise forecasting method in a cavitation inception state of a combined propeller. A target combined propeller geometric model, a fluid mesh model and a fluid dynamics analysis model are built, steady-state cavitation-free turbulence solution, steady-state cavitation turbulence solution and transient state cavitation turbulence solution are carried out sequentially until cavitation multi-phase turbulence of each time step after iteration time steps are reduced is solved, and cavitation noise is worked out along with a built acoustic boundary element mesh. A verification step adaptive to each calculation step is arranged after the corresponding calculation step, and the technical scheme of three criterions for judging the cavitation inception state is firstly created. The wideband spectrum noise forecasting method in the cavitation inception state of the combined propeller can guarantee that the forecasting error of the spectrum level in the position of one third octave center frequency at the frequency band above 800Hz of a rotary paddle and a pump is less than 3db, and the forecasting error of the total sound level is less than 4db, can be used for forecasting the cavitation inception navigational speed of a torpedo or a submarine, and directly serves the scheme design of a novel high-speed and low-noise torpedo and submarine.
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Description

technical field

[0001] The invention relates to a prediction method of propeller cavitation radiation noise, in particular to a prediction method of wide-band spectrum noise of a combined propeller represented by a contra-rotating propeller and a pump-jet propeller in a cavitation incipient state. Background technique

[0002] The counter-rotating propeller (referred to as the counter-rotating propeller) is the main propeller of the existing electrodynamic torpedo, and consists of a coaxial, counter-rotating front propeller (abbreviated as the front propeller) and a rear propeller (abbreviated as the rear propeller). Usually, the diameter of the rear propeller is smaller than that of the front propeller, and the number of blades is less in order to avoid the tip vortex shedding of the front propeller and interact with the leading edge of the blade to radiate sound. The pump jet propeller (abbreviated as the pump jet) is the main propeller for existing thermodynamic torpedoes...

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Embodiment Construction

[0026] Embodiments of the present invention will now be described with reference to the drawings, in which like reference numerals represent like elements.

[0027] Step S1, establishing a three-dimensional geometric model of the combined propeller according to the geometric value of the target combined propeller. The combined propeller is a counter-rotating propeller (referred to as a counter-rotating propeller) or a pump-jet propeller (abbreviated as a pump-jet). According to the geometric value in the design drawing, use UG software to accurately establish the three-dimensional sheet geometry model of the combined propeller of the combined propeller. In addition, 3D CAD software such as Pro / ENGINEER, CATIA or SolidWorks can also be used. In the process of generating the sheet, the geometry of the leading edge, trailing edge and blade tip of the blade should be strictly consistent with the drawing, and the geometry of the blade tip should be accurately described, and the cu...