Arc Duct and Pre-swirl Stators for Propeller Thrust
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Solution Overview
Problem
Existing propulsion systems face challenges in improving efficiency due to the dual effect of ducts, which increase thrust but also create resistance.
Innovation Solution
The apparatus incorporates a duct with an arc shape positioned in front of a propeller and supported by pre-swirl stators that generate a swirl flow opposite to the propeller's rotation direction, enhancing thrust while minimizing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a duct is disposed in front of a propeller to generate additional thrust, then propulsion efficiency is improved, but resistance increases reducing propulsion efficiency
Solution Approach 1:
The invention converts the harmful resistance effect of the duct into a beneficial thrust enhancement by integrating pre-swirl stators that generate counter-rotating swirl flow. This counter-swirl reduces the rotational wake behind the propeller, allowing the duct to generate additional thrust without suffering from excessive resistance, thus transforming the duct's negative resistance effect into a positive thrust contribution
Solution Approach 2:
The pre-swirl stators serve multiple functions: they generate counter-rotating swirl flow to reduce propeller wake, support the duct structure, and optimize flow distribution to the propeller. This multi-functionality allows the system to simultaneously reduce resistance and enhance thrust, resolving the contradiction between these two opposing effects
2Productivity
If pre-swirl stators are added to generate counter-swirl flow, then propulsion efficiency is improved, but device complexity increases
Solution Approach 1:
The invention merges the pre-swirl stator support structure with the duct assembly, creating an integrated unit that reduces overall system complexity. The pre-swirl stators are mounted on the duct or stern boss in a configuration that combines structural support and flow control functions into a single integrated component rather than separate additions
Solution Approach 2:
The pre-swirl stators are divided into multiple segments or blades arranged radially, allowing each segment to independently generate the necessary counter-swirl flow. This segmentation enables efficient flow control while maintaining a compact and manageable structure that can be manufactured and assembled using standard propulsion components
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 increases propeller thrust and improves propulsion efficiency by optimizing the interaction between the duct and pre-swirl stators, reducing the overall resistance and enhancing fuel efficiency.
Implementation Method 1
a plurality of pre-swirl stators for supporting the duct to a stern boss, the plurality of pre-swirl stators generating a swirl flow in a direction opposite to a rotation direction of the propeller
Implementation Method 2
The duct generates additional thrust as it passes through a flow moving backwards along a surface of a hull
Data Source
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AI summary
An apparatus for improving propulsion efficiency is discloses. An apparatus for improving propulsion efficiency according to embodiments of the present invention includes a duct disposed in front of a propeller, having an arc shape, and generating thrust; and a plurality of pre-swirl stators for supporting the duct to a stern boss, the plurality of pre-swirl stators generating a swirl flow in a direction opposite to a rotation direction of the propeller.