FADEC Low-Power Mode for Gas Turbine Bowed Rotor Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face a 'bowed rotor' condition due to thermal expansion after shutdown, which can prevent engine restart and is undesirable for safety and efficiency reasons.
Innovation Solution
A bowed rotor prevention system using a core turning motor driven by a full authority digital engine control (FADEC) in a low-power mode to slowly rotate the engine core, reducing power consumption and mitigating thermal gradients, and including a dry motoring process if the prevention is unsuccessful.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a core turning motor is used to prevent bowed rotor conditions, then reliability is improved, but power consumption increases
Solution Approach 1:
The FADEC operates in a low-power bowed rotor prevention mode where it performs only the essential function of controlling the core turning motor, depowering itself to consume less than 500 watts (ideally about 40 watts) during this specific task, rather than maintaining full operational capabilities
Solution Approach 2:
The core turning motor rotates the engine core periodically at low speeds rather than continuously at high speeds, allowing the system to achieve bowed rotor prevention through intermittent rotation while minimizing power consumption during the shutdown period
2Reliability
If full FADEC power is used for bowed rotor prevention, then prevention effectiveness is improved, but power consumption increases
Solution Approach 1:
The FADEC performs only the minimal necessary control functions for bowed rotor prevention, depowering itself to consume less than 500 watts (ideally about 40 watts) while maintaining adequate control capability for the core turning motor
Solution Approach 2:
The system extracts and isolates the bowed rotor prevention function from the full FADEC operational mode, creating a dedicated low-power mode that uses only the necessary subset of FADEC capabilities for this specific task
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
Effectively prevents bowed rotor conditions by reducing thermal gradients and allowing safe engine restart with reduced power consumption, avoiding high-speed rotations and external power sources, thus enhancing operational reliability and efficiency.
Implementation Method 1
When a gas turbine engine of an aircraft has been shut off for example, after an aircraft has landed at an airport, the engine is hot and due to heat rise, the upper portions of the engine will be hotter than lower portions of the engine. When this occurs thermal expansion may cause deflection of components of the engine which may result in a 'bowed rotor' condition.
Data Source
AI summary
A bowed rotor prevention system for a gas turbine engine includes a core turning motor operable to drive rotation of an engine core of the gas turbine engine. The bowed rotor prevention system also includes a full authority digital engine control (FADEC) that controls operation of the gas turbine engine in a full-power mode and controls operation of the core turning motor to drive rotation of the engine core using a reduced power draw when the FADEC is partially depowered in a low-power bowed rotor prevention mode.