Distributed Propulsion Thermal Management for Motor Overheating

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Solution Overview

Problem

Existing aircraft propulsion systems face inefficiencies due to vortex interactions between main and tail rotors, leading to reduced thrust and increased noise, as well as overheating issues in motors which can cause failure.

Innovation Solution

A distributed propulsion system with thermal management, featuring multiple rotors and motors that can be individually controlled for thrust and temperature regulation, including liquid cooling, to maintain efficient operation and prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If tail rotors are driven at high angular velocities to provide adequate aerodynamic responses, then thrust efficiency is improved, but motor temperature increases leading to overheating and potential failure

Engineering Contradiction:
Improvethrust efficiencyVSAvoidmotor temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

A heat exchanger is introduced as an intermediary component between the motor and the environment. The heat exchanger receives thermal energy from the motor and dissipates it to the surrounding air, preventing motor overheating while allowing the motor to operate at high angular velocities for adequate thrust production

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thermal management system extracts excess heat from the motor through the heat exchanger, separating the heat dissipation function from the motor's primary thrust generation function. This allows the motor to maintain high power output without accumulating excessive heat

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If distributed propulsion system operates at high power output, then propulsion efficiency is improved, but vortex interactions between main and tail rotors increase reducing overall efficiency

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoidenergy loss due to vortex interactions
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the operation of distributed propellers based on real-time conditions. By independently controlling multiple propellers, the system can optimize their operation to minimize vortex interactions while maintaining high overall propulsion efficiency, adapting to changing flight conditions

Inventive Principle:
Principle #15Dynamics

3Reliability

If thermal management system continuously cools motors, then reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvemotor reliabilityVSAvoidenergy consumption for cooling
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The thermal management system operates periodically rather than continuously. The heat exchanger activates when thermal thresholds are approached and allows passive cooling when temperatures are acceptable, reducing energy consumption while maintaining motor reliability through periodic thermal management

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

The system enhances propulsion efficiency by minimizing vortex interference and effectively managing motor temperatures, ensuring stable and safe flight operations by reducing thrust when necessary to prevent overheating and allowing for quick recovery from high-thrust conditions.

Implementation Method 1

a heat exchanger in fluid communication with the hydraulic circuit, the heat exchanger cooling the hydraulic fluid

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3919375B1Distributed propulsion with thermal management
Publication Date: 2023.08.23 TEXTRON INNOVATIONS INC

AI summary

An exemplary distributed propulsion system (110, 210) with thermal management includes two or more rotors (112, 212a-d) individually controlled by associated motors (111, 211a-d) and an input control (107) connected to the associated motors to demand the associated motors produce a demanded thrust, wherein a motor power output of each motor of the associated motors is independently controlled to produce the demanded thrust and to control a motor temperature of one or more of the associated motors.