Underwater Sonar Antenna Cladding with Acoustic Window

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Solution Overview

Problem

Existing underwater vehicles with sonar antennas installed outside the shell experience negative impacts on flow properties due to the antennas' presence, and previous solutions like covers either absorb too much sound or fail to withstand dynamic water pressure.

Innovation Solution

A device with a cover, valve, and outlet opening is used to enclose sonar antennas, featuring an acoustic window for sound wave transmission and a waterproof design to withstand water pressure, with a valve for water exchange to maintain hydrostatic pressure equilibrium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sonar antennas are mounted outside the underwater vehicle hull, then sound detection capability is improved, but flow characteristics deteriorate

Engineering Contradiction:
Improvesound detection capabilityVSAvoidflow characteristics
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

An acoustic window made of acoustically transparent material is introduced as an intermediary between the sonar antenna and the external water environment. This window allows sound waves to pass through while maintaining the streamlined hull shape, thus preserving both sound detection capability and flow characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If sonar antennas are covered by a hull, then flow characteristics are improved, but sound wave transmission is absorbed

Engineering Contradiction:
Improveflow characteristicsVSAvoidsound wave transmission
Core Design Contradiction:
Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The hull is designed with local quality variation: most of the hull structure provides streamlined flow characteristics, while a specific local region (the acoustic window) is made of acoustically transparent material to allow sound wave transmission. This resolves the contradiction by making different parts of the hull serve different functions.

Inventive Principle:
Principle #3Local quality

3Strength

If a thick hull is used to withstand dynamic water pressure, then structural strength is improved, but sound wave absorption increases

Engineering Contradiction:
Improvestructural strengthVSAvoidsound wave transmission
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

The acoustic window is designed with local quality: it is made of acoustically transparent material with optimized thickness to balance structural strength and sound transmission. The rest of the hull can be thicker for strength, while the acoustic window region is specifically designed for acoustic transparency.

Inventive Principle:
Principle #3Local quality

4Measurement precision

If the acoustic window is made thin to reduce sound absorption, then sound transmission is improved, but resistance to dynamic water pressure decreases

Engineering Contradiction:
Improvesound transmissionVSAvoidresistance to dynamic water pressure
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The acoustic window is made of composite materials that combine acoustic transparency with structural strength. These composite materials allow thin construction for sound transmission while maintaining adequate resistance to dynamic water pressure through material properties rather than thickness.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device improves the flow properties of underwater vehicles by allowing sound wave transmission while withstanding dynamic water pressure, and ensures water composition homogeneity to enhance sound wave propagation.

Implementation Method 1

The window (30) is designed to allow sound waves from the environment of the device to pass into the interior of the device

Methodology Applied
Scientific EffectSound wave transmission: Sound

Implementation Method 2

The valve (26) can allow water surrounding the device 20 to flow into the device 20

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Implementation Method 3

The valve (26) is designed to prevent water present in the device 20 from flowing out of the device 20 through the valve (26)

Methodology Applied
Scientific EffectPressure differential control: Pressure Gradient

Implementation Method 4

The outlet opening (28) is designed to allow water present in the device 20 to flow out of the device 20, so that a water exchange takes place in the device 20 due to the higher pressure outside the device (20) that occurs during the underwater vehicle's travel

Methodology Applied
Scientific EffectPressure-driven outflow: Pressure Gradient

Data Source

PatentEP3917827B1Device for cladding an underwater sound receiver
Publication Date: 2025.04.23 ATLAS ELEKTRONIK GMBH
  • EP3917827B1 patent drawingFigure 1
  • EP3917827B1 patent drawingFigure 2

AI summary

Embodiments show a device for cladding an underwater sound receiver, for example a (sonar) antenna, having a covering, a valve and an outlet opening. The covering can accommodate the underwater sound receiver. The covering further has, in a first region, an (acoustic) window, said window being designed to let sound waves pass through. The valve is designed to let water surrounding the device flow into the covering and to prevent water present in the covering from flowing out of the covering. The outlet opening is designed to let water present in the covering flow out.