Flow Guide Arrangement for Retractable Thruster Tunnel Leakage
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Solution Overview
Problem
Retractable thrusters in marine vessels experience flow leakage and increased noise and fuel consumption due to bypass flow when in tunnel mode, and suffer from flow resistance issues that hamper efficiency and steerability in drive mode.
Innovation Solution
A flow guide arrangement is implemented on the periphery of the thruster housing, opposite to the propeller, which minimizes flow leakage and turbulent flow in tunnel mode and maintains low flow resistance and high steerability in drive mode by guiding the flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the retractable thruster is in tunnel mode, then it can assist in moving the ship sideways for docking purposes, but flow leakage occurs from the tunnel to the well causing bypass flow that reduces thrust efficiency and increases noise and fuel consumption
Solution Approach 1:
A flow guide arrangement is introduced as an intermediary component between the tunnel and the well. The flow guide includes a guide body with a guide surface that directs water flow from the tunnel towards the propeller, preventing leakage into the well. This mediator component resolves the contradiction by maintaining tunnel mode functionality while eliminating the energy loss caused by bypass flow.
Solution Approach 2:
The invention converts the potentially harmful bypass flow into beneficial directed flow. The flow guide arrangement captures water that would otherwise leak into the well and redirects it towards the propeller, transforming energy loss into useful thrust. This principle resolves the contradiction by turning the harmful leakage effect into a benefit that enhances propeller efficiency.
2Force
If the retractable thruster is in tunnel mode, then it can provide thrust for maneuvering, but flow leakage to the well causes bypass flow that reduces thrust efficiency
Solution Approach 1:
The flow guide arrangement acts as an intermediary that intercepts leaking flow and redirects it towards the propeller. The guide body with its specifically designed guide surface ensures that water flow is channeled efficiently to the propeller inlet, preventing energy loss and maximizing thrust generation in tunnel mode.
Solution Approach 2:
The invention transforms the harmful bypass flow that would otherwise represent energy loss into a beneficial contribution to propeller thrust. By redirecting the leaking water towards the propeller, the flow guide converts what was previously wasted energy into useful thrust, thereby resolving the contradiction between maintaining thrust and improving thrust efficiency.
3Adaptability or versatility
If the retractable thruster operates in drive mode outside the hull, then it can generate thrust in any desired direction, but flow resistance from surrounding structures hampers efficiency and steerability
Solution Approach 1:
The flow guide arrangement serves as a mediator between the propeller and the surrounding water environment in drive mode. The guide body and guide surface are designed to optimize flow patterns around the propeller, reducing turbulent flow and flow resistance caused by surrounding structures. This intermediary component protects the propeller from harmful flow resistance while maintaining full steerability.
Solution Approach 2:
The flow guide arrangement employs curved surfaces and streamlined geometry to reduce flow resistance. The guide surface is designed with appropriate curvature to guide water flow smoothly around the propeller, minimizing turbulence and drag. This application of curved geometry helps resolve the contradiction by reducing flow resistance while preserving the thruster's ability to operate in any direction.
4Device complexity
If no flow guide arrangement is used, then the structure is simpler, but flow leakage increases causing energy loss and reduced thrust efficiency
Solution Approach 1:
The flow guide arrangement is a relatively simple intermediary component that can be added to the existing thruster structure. It consists of a guide body with a guide surface, forming a straightforward geometric addition that prevents flow leakage without requiring complex mechanical systems, control mechanisms, or multiple moving parts. This simple mediator effectively reduces energy loss while adding minimal structural complexity.
Solution Approach 2:
The flow guide arrangement extracts and redirects the problematic bypass flow before it can cause energy loss. By introducing this single functional component, the invention addresses the energy loss problem without requiring comprehensive redesign of the entire thruster system, thereby maintaining structural simplicity while achieving significant energy efficiency improvements.
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 flow guide arrangement enhances thrust in tunnel mode, reduces leak to the well, and maintains high steering properties and low flow resistance when the thruster is outside the hull, resulting in improved efficiency and reduced fuel consumption.
Implementation Method 1
a flow guide arrangement, which may minimize a bypass flow and/or turbulent flow
Implementation Method 2
a propeller arranged rotatable relative to a longitudinal axis of the thruster housing, and a drive means for rotating the propeller
Data Source
Figure 1~3
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Figure 7~8
AI summary
A flow guide arrangement of a retractable thruster unit (1), the retractable thruster unit comprising a thruster housing (2) and a stem (3) for connecting the thruster housing (2) to a support and lifting structure, wherein the thruster housing (2) is arranged rotatable around an axis (V) of the stem (3), a propeller (4) arranged rotatable relative to a longitudinal axis (L) of the thruster housing (2), and a drive means for rotating the propeller. The flow guide (10) is arranged on the periphery of the thruster housing (2) on a side opposite to the propeller (4).