Hydrofoil Shaft Brackets for Multi-Screw Ship Propulsion Efficiency
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Solution Overview
Problem
Multi-screw ships with external propeller shafts lack effective solutions to reduce drive power requirements, which affects energy efficiency.
Innovation Solution
The arrangement includes at least two shaft brackets with hydrofoil-shaped arms and a fore-nozzle, where the hydrofoils are designed to influence propeller inflow, generating pre-rotation and optimizing energy efficiency by reducing drive power requirements through fluidic optimization of propeller inflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional shaft blocks with simple support arms are used for external propeller shafts, then the structure is simple and easy to manufacture, but the propulsion power requirement is high and energy efficiency is poor
Solution Approach 1:
The shaft block structure is segmented into multiple functional components: support arms for mechanical support, hydrofoils for flow optimization, and pre-nozzles for inflow conditioning. Each segment performs a specific function, allowing the complex system to achieve energy efficiency while maintaining manufacturability through modular assembly
Solution Approach 2:
The support arms serve dual functions: providing mechanical support for the propeller shaft and acting as hydrofoils to optimize water flow. This multi-functionality reduces the need for separate components, balancing energy efficiency improvement with structural simplicity
2Productivity
If shaft block arms are designed with hydrofoil profiles and pre-nozzles are added, then propeller inflow is optimized and drive power requirement decreases, but manufacturing complexity and device complexity increase
Solution Approach 1:
The pre-nozzles are positioned upstream of the propeller to pre-condition the water flow before it reaches the propeller blades. This preliminary action optimizes the inflow angle and reduces turbulence, improving propulsion efficiency without requiring complex modifications to the propeller itself
Solution Approach 2:
The hydrofoil profiles of the support arms are designed with specific geometric parameters (camber, thickness distribution, angle of attack) to optimize flow characteristics. By carefully selecting these parameters, the design achieves energy efficiency while keeping the manufacturing processes within standard capabilities
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 arrangement effectively reduces the drive power requirement of multi-screw ships by optimizing propeller inflow, leading to improved energy efficiency and lower propulsion energy needs.
Implementation Method 1
each of the at least two devices comprises at least one hydrofoil... at least one shaft bracket arm has an hydrofoil profile... the at least one hydrofoil has an angle of attack
Implementation Method 2
the at least one hydrofoil is designed to be twisted, and wherein the angle of attack of the at least one hydrofoil is greater in the region of the at least one hydrofoil facing the shaft bracket than in the rest of the at least one hydrofoil
Implementation Method 3
Each of the at least two devices of the arrangement comprises a pre-nozzle, wherein each of the at least two devices is provided with at least one fin which is designed as a hydrofoil of the device, wherein the at least one fin is arranged inside the pre-nozzle and outside on the pre-nozzle
Data Source
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AI summary
The invention relates to an arrangement for multi-screw vessels, in particular twin-screw vessels, with external propeller shafts, as well as a method for producing such an arrangement. The arrangement according to the invention is particularly suitable for a propulsion system of such a multi-screw vessel and for improving its energy efficiency.