Aircraft Engine Power Limiting via Propeller Thrust Constraints

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing engine control systems for propeller-driven aircraft do not consider propeller-related constraints when modulating engine output power, leading to potential mechanical or thermal damage.

Innovation Solution

A method and system that set a maximum engine power limit as the lowest value among thrust, mechanical, and thermal limits, incorporating propeller operation conditions and external aircraft factors to prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If engine output power is increased to improve aircraft performance, then power and speed are improved, but the propeller may exceed its thrust capacity causing mechanical damage

Engineering Contradiction:

Improveengine output powerVSAvoidpropeller thrust capacity

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The control system continuously monitors propeller operating conditions including blade pitch angle, rotational speed, and aircraft airspeed. Based on this feedback, the system dynamically adjusts the engine output power to ensure it does not exceed the propeller's thrust capacity while still maximizing performance within safe limits

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically determines the maximum allowable engine power based on real-time propeller operating conditions. As propeller blade pitch and rotational speed change during operation, the engine power limit is continuously adjusted to match the propeller's current thrust capacity, enabling optimal performance across different flight regimes

Inventive Principle:

Principle #15Dynamics

2Reliability

If engine power limit is set based on propeller thrust capacity, then propeller safety is improved, but engine power output is reduced

Engineering Contradiction:

Improvepropeller safetyVSAvoidengine power output

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The system changes the power limit parameter dynamically based on propeller operating conditions. Rather than using a fixed conservative limit, the engine power output limit is adjusted as a function of propeller blade pitch angle and rotational speed, allowing the engine to operate at higher powers when the propeller can safely handle the thrust

Inventive Principle:

Principle #35Parameter changes

3Reliability

If engine control system monitors multiple propeller conditions to determine power limits, then propeller safety is improved, but device complexity increases

Engineering Contradiction:

Improvepropeller protectionVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control system is designed to serve multiple functions: it monitors propeller blade pitch, rotational speed, and aircraft airspeed while simultaneously determining the maximum allowable engine power and controlling engine output. This multi-functional approach consolidates what could be separate systems into a unified control architecture

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3360785B1Methods and systems for controlling operation of aircraft engines

Publication Date: 2020.11.11 PRATT & WHITNEY CANADA CORP

Figure 1
Figure 2A
Figure 2B

AI summary

A method and a system for controlling operation of an engine (110) of an aircraft. A first engine power limit associated with a thrust limit for a propeller (120) coupled to the engine (110) is obtained. The first engine power limit is compared to a second engine power limit associated with a mechanical limit for the engine (110) and to a third engine power limit associated with a thermal limit for the engine (110). A maximum engine power limit is set at a lowest value of the first, second, and third engine power limits.