ISO 20233-1:2018 PDF

Ships and marine technology — Model test method for propeller cavitation noise evaluation in ship design — Part 1: Source level estimation

Первая страница стандарта ISO 20233-1:2018

Открыть превью (PDF)

Название (английский):

ISO 20233-1:2018

Ships and marine technology — Model test method for propeller cavitation noise evaluation in ship design — Part 1: Source level estimation

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 13
Дата публикации:: 23 февраля 2018 г.
Издание:: ISO IS 20233 edition 1 version 1
ICS:: 47.020.20

Язык документа:

ruen

Срок поставки:3 раб. дн. (перевод)

Цена:195 €

Описание (английский):

ISO 20233-1:2018 specifies a model test method for propeller cavitation noise evaluation in ship design. The procedure comprises reproduction of noise source, noise measurements, post processing and scaling. The target noise source is propeller cavitation. Thus, this document describes the test set-up and conditions to reproduce the cavitation patterns of the ship based on the similarity laws between the model and the ship. The propeller noise is measured at three stages. The measurement targets for each stage are propeller cavitation noise, background noise, and transmission loss. For the source level evaluations, corrections for the background noise and the transmission loss are applied to the measured propeller cavitation noise. Finally, the full-scale source levels are estimated from the model scale results using a scaling law.

Технические детали

Технический комитет: ISO/TC 8/SC 8 - Ship design
SKU: ISO 20233-1:2018

Abstract

Overview

ISO 20233-1:2018 - "Ships and marine technology - Model test method for propeller cavitation noise evaluation in ship design - Part 1: Source level estimation" defines a standardized model-test procedure to estimate propeller cavitation noise source levels for ship design. The standard covers reproduction of the noise source (cavitation patterns), noise measurements, post‑processing (background noise and transmission loss corrections), and scaling from model to full scale using similarity laws.

Key topics and technical requirements

Test setup and facilities: Suitable facilities include variable‑pressure cavitation tunnels, circulating water channels, and depressurized towing tanks. Wake generation can be by wake screens or ship models depending on tunnel size.
Model propeller requirements: Geometry accuracy per ITTC guidelines; typical model diameters cited are 180–300 mm. Maximize Reynolds number within facility limits to reduce scale effects.
Measurement stages: Noise is measured in three stages - propeller cavitation noise, background noise, and transmission loss (reference field) - with corrections applied to derive source level.
Instrumentation and data acquisition: Hydrophones, signal conditioning, multi‑channel synchronization, sampling frequency, resolution, filtering and acquisition time are specified to ensure reliable SPL measurement.
Post-processing and scaling: Procedures include sound pressure level calculation, background noise adjustment, transmission loss correction, model‑scale source level calculation, and application of a scaling law to estimate full‑scale source levels.
Key acoustical concepts: Definitions and usage of terms such as acoustic centre, reference distance (1 m), cavitation number, and reference field.
Quality and uncertainty: Calibration, uncertainty assessment, and optional methods for full‑scale prediction are addressed.

Applications and users

ISO 20233-1:2018 is intended for professionals and organizations involved in:

Ship design and naval architecture - assessing propeller noise at early design stages.
Underwater acoustics and environmental compliance - quantifying ship noise for regulatory or environmental impact studies.
Acoustic test facilities and cavitation tunnel operators - establishing repeatable model tests.
Propeller and propulsion system designers - evaluating cavitation mitigation measures.
Military and special‑purpose vessels where low propeller cavitation noise is critical.

Practical benefits include standardized, reproducible model testing for reliable full‑scale noise prediction and improved design decisions to reduce underwater radiated noise.

Related standards

ISO 17208-1:2016 - underwater acoustics measurement requirements.
IEC 61260 - octave and fractional‑octave filters.
ITTC Recommended Procedures and Guidelines - model propeller and cavitation test methodologies.

Keywords: ISO 20233-1, propeller cavitation noise, model test, source level estimation, ship design, cavitation tunnel, underwater acoustics, noise measurements, scaling law.

Overview

Key topics and technical requirements

Test setup and facilities: Suitable facilities include variable‑pressure cavitation tunnels, circulating water channels, and depressurized towing tanks. Wake generation can be by wake screens or ship models depending on tunnel size.
Model propeller requirements: Geometry accuracy per ITTC guidelines; typical model diameters cited are 180–300 mm. Maximize Reynolds number within facility limits to reduce scale effects.
Measurement stages: Noise is measured in three stages - propeller cavitation noise, background noise, and transmission loss (reference field) - with corrections applied to derive source level.
Instrumentation and data acquisition: Hydrophones, signal conditioning, multi‑channel synchronization, sampling frequency, resolution, filtering and acquisition time are specified to ensure reliable SPL measurement.
Post-processing and scaling: Procedures include sound pressure level calculation, background noise adjustment, transmission loss correction, model‑scale source level calculation, and application of a scaling law to estimate full‑scale source levels.
Key acoustical concepts: Definitions and usage of terms such as acoustic centre, reference distance (1 m), cavitation number, and reference field.
Quality and uncertainty: Calibration, uncertainty assessment, and optional methods for full‑scale prediction are addressed.

Applications and users

ISO 20233-1:2018 is intended for professionals and organizations involved in:

Ship design and naval architecture - assessing propeller noise at early design stages.
Underwater acoustics and environmental compliance - quantifying ship noise for regulatory or environmental impact studies.
Acoustic test facilities and cavitation tunnel operators - establishing repeatable model tests.
Propeller and propulsion system designers - evaluating cavitation mitigation measures.
Military and special‑purpose vessels where low propeller cavitation noise is critical.

Practical benefits include standardized, reproducible model testing for reliable full‑scale noise prediction and improved design decisions to reduce underwater radiated noise.

Related standards

ISO 17208-1:2016 - underwater acoustics measurement requirements.
IEC 61260 - octave and fractional‑octave filters.
ITTC Recommended Procedures and Guidelines - model propeller and cavitation test methodologies.

Keywords: ISO 20233-1, propeller cavitation noise, model test, source level estimation, ship design, cavitation tunnel, underwater acoustics, noise measurements, scaling law.

ISO 20233-1:2018 PDF

Технические детали

Abstract

Overview

Key topics and technical requirements

Applications and users

Related standards

Похожие стандарты

Abstract

Overview

Key topics and technical requirements

Applications and users

Related standards

Похожие стандарты

Underwater acoustics — Quantities and procedures for description and measurement of underwater sound from shi…

Electroacoustics - Octave-band and fractional-octave-band filters - Part 3: Periodic tests

Ships and marine technology. Model test method for propeller cavitation noise evaluation in ship design. Sour…