Dome Diffuser Pump for Underwater Vehicle Acoustic Stealth
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Solution Overview
Problem
Existing underwater vehicles, such as torpedoes, face challenges in acoustic discretion due to noise radiation from conventional electrolyte circulation pumps, which can lead to early detection by acoustic detection means.
Innovation Solution
The design incorporates a mixed flow pump with a non-axisymmetric impeller and a diffuser shaped like a dome, allowing electrolyte discharge parallel to the pump axis, reducing acoustic noise and improving circulation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional mixed flow pump with axisymmetric impeller is used, then the electrolyte circulation is efficient, but acoustic noise is radiated strongly in radial directions
Solution Approach 1:
The patent applies asymmetry by using a non-axisymmetric impeller with unequal blade spacing and a diffuser with asymmetric internal face vanes. This asymmetric configuration disrupts the symmetric radial noise radiation pattern of conventional pumps, redirecting acoustic energy and reducing noise in critical radial directions while maintaining circulation efficiency.
Solution Approach 2:
The patent redirects the noise radiation from radial directions to axial directions by designing the diffuser to discharge electrolyte axially rather than radially. This dimensional change in flow direction transforms the noise radiation pattern, concentrating acoustic energy along the axis where it is less detectable by side-mounted acoustic sensors.
2Object-affected harmful factors
If the diffuser discharges electrolyte radially, then the pump structure is simple, but acoustic noise propagates strongly in radial directions
Solution Approach 1:
The diffuser is designed to change the discharge direction from radial to axial, fundamentally altering the noise propagation pattern. The asymmetric internal face with offset vanes further modifies the flow pattern to discharge electrolyte axially over 360 degrees, reducing radial noise while the dome shape manages the complexity through geometric integration.
Solution Approach 2:
The dome-shaped diffuser structure uses curved surfaces to smoothly redirect flow from radial to axial directions. This spherical geometry naturally distributes the flow and noise radiation patterns, reducing concentrated radial noise peaks while maintaining structural integrity and managing complexity through form-follows-function design.
3Object-affected harmful factors
If a non-axisymmetric impeller is used, then acoustic noise is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The non-axisymmetric impeller deliberately introduces controlled asymmetry with unequal blade spacing to disrupt noise radiation patterns. While this increases manufacturing precision requirements compared to symmetric designs, the asymmetric configuration is optimized to achieve superior noise reduction, with the precision requirements being manageable through modern manufacturing techniques.
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
This configuration reduces acoustic energy radiation, enhancing the vehicle's discretion and making it harder to detect, while maintaining efficient electrolyte circulation and operation of the electrochemical cell.
Implementation Method 1
an electrochemical cell for producing electrical energy
Implementation Method 2
a motorized wheel rotatably mounted in a diffuser
Data Source
Figure 1~2
Figure 3~4
AI summary
This underwater vehicle, which has an electrolytically activated electrochemical battery intended to produce electrical energy for powering said vehicle, the electrochemical battery having: - an electrochemical cell (3) for producing electrical energy, - a reservoir (4) intended to contain the electrolyte, - means (7) for circulating the electrolyte between the electrochemical cell (3) and the reservoir (4), these circulation means comprising a helico-centrifugal pump disposed axially in the reservoir and comprising a motorized wheel mounted in a rotary manner in a diffuser, is characterized in that the diffuser is in the overall shape of a dome for discharging the flow of electrolyte at the outlet of the pump in a direction approximately parallel to the axis of the pump and thus of the reservoir.