Underwater Cover With Rotating Flow for Stable Water-Free Spaces

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Solution Overview

Problem

Existing underwater construction and inspection technologies face challenges in creating a stable water-free space near underwater surfaces due to air escaping through gaps, especially on non-horizontal or non-contact surfaces, leading to reduced effectiveness and mobility.

Innovation Solution

An underwater cover device with a cover body and gas source that generates a rotating water flow inside, using the pressure gradient and centrifugal inertial force to prevent air from escaping, forming a water-free space by injecting air through nozzles or blades, and utilizing air chambers and drainage channels to maintain the space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple cover body is used to create a water-free space, then the device structure is simple, but air escapes through gaps between the cover body and the underwater surface, making it impossible to maintain a stable water-free space

Engineering Contradiction:
Improvedevice structureVSAvoidwater-free space stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-coating the inner surface of the cover body with a hydrophobic material before deployment. This preliminary preparation creates a water-repellent barrier that prevents water from penetrating through gaps between the cover body and the underwater surface, thereby maintaining the stability of the water-free space without requiring complex additional structures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes pneumatic principles by introducing air into the cover body to create a pressurized air chamber. This pneumatic pressure counteracts the external water pressure and prevents water from entering through gaps, while the hydrophobic coating enhances this effect by repelling water at the interface. The combination of pneumatic pressure and hydrophobic properties maintains a stable water-free space.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of operation

If the cover body is moved away from the solid surface, then the device gains mobility, but a large gap forms between the cover body and the solid surface, allowing water to enter and preventing formation of a water-free space

Engineering Contradiction:
Improvedevice mobilityVSAvoidwater-free space formation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs pneumatic principles by continuously supplying air into the cover body through a gas source. This pressurized air expands to fill the gap between the cover body and the solid surface, preventing water from entering. The pneumatic pressure dynamically adapts to maintain the water-free space regardless of the cover body's position or mobility, enabling both movement and stable space formation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting the air pressure and flow rate from the gas source based on the cover body's position and the size of the gap. When the cover body moves away from the surface, the system increases air supply pressure to compensate for the larger gap, thereby maintaining the water-free space. This dynamic parameter adjustment enables both mobility and reliable space formation.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the solid surface is not horizontal, then the device can operate on various surface orientations, but air escapes through gaps due to buoyancy, allowing water to enter the cover body

Engineering Contradiction:
Improvesurface orientation adaptabilityVSAvoidair retention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies asymmetry by strategically positioning the gas source and air supply outlets at specific locations on the cover body, typically at the highest point or opposite to the expected water pressure direction. This asymmetric arrangement ensures that pressurized air is delivered to the most critical areas where buoyancy-driven air escape is most likely to occur, effectively counteracting the effect of non-horizontal surfaces.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent uses parameter changes by dynamically adjusting air supply pressure and flow rate in response to surface orientation. Sensors detect the angle and position of the cover body relative to the horizontal plane, and the control system adjusts the gas source parameters accordingly. On steeper or inverted surfaces, the system increases air pressure to counteract stronger buoyancy forces, thereby maintaining air retention and water-free space stability across various orientations.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If a cofferdam structure is used with atmospheric pressure inside, then a water-free space can be created, but the structure cannot be moved due to pressure difference sealing requirements

Engineering Contradiction:
Improvewater-free space creationVSAvoiddevice mobility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by transitioning from a static, rigid cofferdam structure to a dynamic, flexible cover body system. The cover body can expand and contract, and the gas source dynamically adjusts air pressure to maintain the water-free space during movement. This dynamic system allows the device to be moved to different locations and orientations while continuously maintaining the water-free space, unlike the immobile cofferdam.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses parameter changes by continuously adjusting the internal air pressure of the cover body during movement. As the cover body moves or changes orientation, the gas source modifies the air pressure parameters to compensate for changes in external water pressure and buoyancy forces. This dynamic parameter adjustment enables both mobility and reliable water-free space creation, resolving the contradiction between the two requirements.

Inventive Principle:
Principle #35Parameter changes

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 effectively creates a water-free space on non-horizontal surfaces and allows movement without friction, enhancing underwater operations by preventing air loss and maintaining a stable environment for tasks like welding and imaging.

Implementation Method 1

forming a rotating water flow inside the cover body. The gas source supplies air into the cover body, and the rotating water flow prevents the air from escaping through the gap between the open end face and the underwater surface

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

the rotating water flow prevents the air from escaping through the gap between the open end face and the underwater surface, thereby forming a water-free space on the underwater surface

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4640952A1Underwater cover device
Publication Date: 2025.10.29 ZHEJIANG UNIV
  • EP4640952A1 patent drawingFigure 1~3
  • EP4640952A1 patent drawingFigure 4~5
  • EP4640952A1 patent drawingFigure 6~7

AI summary

The invention discloses an underwater cover device, comprising a cover body and a gas source connected to the cover body. The cover body has an open end face directed towards an underwater surface, forming a gap between the open end face and the underwater surface. A rotating water flow is formed inside the cover body, and the gas source supplies air into the cover body. The rotating water flow prevents the air from escaping through the gap between the cover body and the underwater surface, thereby forming a water-free space on the underwater surface. This device is applicable to underwater surfaces at any inclination angle and can effectively establish a water-free space even if there is a gap or no contact between the underwater cover device and the underwater surface, demonstrating excellent applicability.