Stator Vane Angular Setting for Pusher Propeller

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Solution Overview

Problem

There is no optimized, simple, and effective system for angularly setting an annular row of stator vanes downstream of a pusher propeller in an aircraft propulsion system, which is complex and lacks a method for optimized angular setting as a function of flight phase.

Innovation Solution

A method is developed to determine the angular setting of the annular row of stator vanes by establishing a theoretical model of the pusher propeller, calculating dimensionless parameters, and using a pre-constructed database to determine the optimal angular setting based on the angle between the airflow and the pusher propeller plane, and the Mach number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a complex control system is used to determine the angular setting of stator vanes, then the propulsion efficiency can be optimized, but the device complexity and difficulty of implementation increase

Engineering Contradiction:

Improvepropulsion efficiencyVSAvoidcontrol system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent pre-calculates and stores optimal angular settings for stator vanes in a database during ground phase, covering various flight conditions. During actual flight, the system only needs to retrieve pre-computed values based on current operating parameters, eliminating the need for complex real-time calculations and significantly reducing control system complexity while maintaining optimization.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical control mechanisms with a simplified electronic control system that uses a database lookup approach. Instead of using complex mechanical linkages or real-time computational algorithms, the system uses pre-stored data tables that can be quickly queried and processed by standard electronic controllers, reducing both complexity and computational requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If real-time calculations are performed to determine optimal angular setting, then the system adapts to changing flight conditions, but the computational time and processing requirements increase

Engineering Contradiction:

Improveadaptability to flight conditionsVSAvoidcomputational time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs all complex aerodynamic calculations and determines optimal angular settings during the ground phase when computational resources are abundant. These pre-computed values are stored in a database structured by flight conditions. During actual flight, the system simply queries the database based on current parameters, reducing real-time computational requirements to minimal data retrieval and interpolation operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system pre-establishes the relationship between flight parameters and optimal angular settings through ground-based simulations and tests. This preliminary characterization allows the flight control system to use simple lookup tables during operation, avoiding the need for time-consuming real-time aerodynamic calculations while maintaining full adaptability to varying flight conditions.

Inventive Principle:

Principle #10Preliminary 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

This method simplifies the control of the annular row of stator vanes, making it more robust to changes in flight conditions, and allows for the optimization of thrust generation by determining the optimum angular setting of the stator vanes in real-time.

Implementation Method 1

An annular row of stator vanes 6 is arranged downstream of the pusher propeller 4 in order to convert gyration induced by the pusher propeller 4 into an axial advance velocity and thereby increase the thrust generated

Methodology Applied

Scientific EffectGyration conversion:

Implementation Method 2

defining dimensionless parameters including at least a power coefficient Cp,1, a pull coefficient CT,1 and an advance ratio J1 of the pusher propeller

Methodology Applied

Scientific EffectDimensionless parameter calculation:

Implementation Method 3

deducing an angle φ12 between the velocity of the airflow incident on the annular row of stator vanes and a plane of rotation of the pusher propeller

Methodology Applied

Scientific EffectAngle calculation:

Implementation Method 4

determining an angular setting to be applied to the annular row of stator vanes from the angle, a Mach number associated with the velocity of the airflow incident on the pusher propeller

Methodology Applied

Scientific EffectMach number: Speed of Sound

Data Source

PatentUS12221223B2System for determining the angular setting of an annular row of stator vanes

Publication Date: 2025.02.11 SAFRAN SA

AI summary

A method determines the angular setting (β_2) of an annular row of stator vanes arranged downstream of a pusher propeller of a propulsion system with a longitudinal axis. The annular row of stator vanes receives an air flow having a velocity (V2) including a longitudinal component (Viz) and a tangential component (V_iθ) associated with the velocity of gyration generated by the pusher propeller. The method includes the steps of establishing a theoretical model of the pusher propeller using a power (P1) and a mechanical speed (N1) associated with said pusher propeller, and flight conditions that include a velocity of the airflow incident on the pusher propeller, the altitude of said propulsion system and ambient temperature. The method further includes the step of determining an angular setting (β_1) of the pusher propeller from the theoretical model.