Propeller Flow Adjustment for Thrust and Hydrogeneration

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Solution Overview

Problem

Existing electric motor drive systems in watercraft face challenges in optimizing propeller flow characteristics for both propulsion and energy generation, with separate hydrogenerators adding weight and space, especially on smaller vessels.

Innovation Solution

A method and system that adjusts propeller flow characteristics based on the operating state, using modules to determine the state and adjustment means to optimize inflow velocity and shape, including Kort nozzles, guide vanes, and propeller blade adjustments, allowing efficient operation in thrust and generator modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a separate hydrogenerator is added to generate electrical energy, then energy generation capability is improved, but weight and space requirements increase

Engineering Contradiction:
Improveenergy generation capabilityVSAvoidweight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The patent combines the propulsion function and energy generation function into a single propeller system. The propeller serves dual purposes: generating thrust for propulsion and generating electrical energy through hydrogeneration when driven by water current, thereby eliminating the need for a separate hydrogenerator and reducing overall system weight

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The propeller is designed with multi-functionality, capable of operating in different modes including thrust state (propulsion), free state (minimal resistance), blocked state (maximal resistance), and generator state (energy generation). This universal design allows the same component to perform multiple functions across different operating conditions

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Power

If propeller flow characteristics are optimized for thrust state, then propulsion efficiency is improved, but performance in generator state deteriorates

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoidperformance across operating states
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic adjustment of propeller flow characteristics through adjustable pitch angles and variable geometry components. The propeller can change its blade pitch and flow direction dynamically to optimize performance for each operating state, transitioning smoothly between thrust optimization and energy generation optimization

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key parameters such as pitch angle, flow direction, and blade geometry based on the detected operating state. By varying these parameters, the propeller adapts its flow characteristics to match the requirements of either thrust generation or energy generation, resolving the contradiction between optimized thrust performance and generator performance

Inventive Principle:
Principle #35Parameter changes

3Power

If the propeller operates in generator state, then energy harvesting is improved, but propulsion capability deteriorates

Engineering Contradiction:
Improveenergy harvesting capabilityVSAvoidthrust
Core Design Contradiction:
PowerVSForce

Solution Approach 1:

The system employs periodic switching between different operating states based on energy needs and propulsion requirements. The propeller alternates between thrust-optimized mode and generation-optimized mode, allowing the watercraft to accumulate energy over time while maintaining adequate propulsion capability through cyclical operation

Inventive Principle:
Principle #19Periodic action

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

Maximizes efficiency in both thrust and generator states by optimizing propeller flow characteristics, reducing weight and space requirements, and enhancing energy harvesting capabilities.

Implementation Method 1

The propeller blades experience dynamic propulsion, the axial component of which is absorbed by the propeller bearing and referred to as thrust

Methodology Applied
Scientific EffectDynamic propulsion:

Implementation Method 2

If a generator is driven by a water current via a propeller, this is called hydrogeneration

Methodology Applied
Scientific EffectHydrogeneration:

Data Source

PatentEP3878732B1Method and device for adjusting the voltage of a propeller
Publication Date: 2025.10.22 TORQEEDO
  • EP3878732B1 patent drawingFigure 1~2
  • EP3878732B1 patent drawingFigure 3A~3B
  • EP3878732B1 patent drawingFigure 3C~3D

AI summary

The present invention relates to a method (1) and a device (10) for adjusting flow properties of a propeller (103) of a propulsion system (100) for watercraft (1000), in particular for boats and ships, depending on the operating state, comprising the steps of determining the operating state (2) of the propulsion system (100), wherein in the propulsion system (100) either a thrust state or a generator state, in particular a hydrogeneration state for generating energy by hydrogeneration, exists and adjusting the flow properties (3) of the propeller (103) based on the determined operating state.