Active Spool Scheduling Valve for Fuel Nozzle Noise Control

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Solution Overview

Problem

Conventional fuel injectors with passive flow scheduling valves in gas turbine engines face challenges in managing noise and structural health due to excitation of natural frequencies at certain heat release conditions, requiring additional hardware that increases cost, weight, and power consumption.

Innovation Solution

The introduction of a solenoid valve connected to a hydromechanical valve spool in the injector, allowing for active control of flow through a scheduling valve assembly, with proportional or discrete control options, to regulate fuel flow and mitigate noise and structural issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If additional flow dividing hardware and fuel manifolds are added to adjust fuel scheduling and decouple heat release from noise, then noise and structural health are improved, but cost, weight, and power requirements increase significantly

Engineering Contradiction:
Improvenoise and structural healthVSAvoidcost, weight, and power requirements
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the flow control function with the existing passive scheduling valve by integrating a solenoid actuator directly onto the valve spool. This merging approach allows active control capability to be added without requiring separate flow dividing hardware or additional fuel manifolds, thus avoiding the weight and complexity penalties of the conventional approach

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The solenoid actuator serves as an intermediary device that converts electrical control signals into mechanical displacement of the valve spool. This intermediary mechanism enables precise control of fuel flow scheduling without requiring complex mechanical linkages or additional flow paths, thereby reducing overall system complexity while achieving noise mitigation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If passive flow scheduling valves are used to regulate fuel flow based on inlet pressure, then the system is simple and reliable, but noise occurs at certain heat release conditions due to excitation of natural frequencies

Engineering Contradiction:
Improvesystem simplicityVSAvoidnoise at certain operating conditions
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent transforms the static passive valve into a dynamic controllable valve by adding solenoid actuation. The valve spool can now be actively positioned to modify flow scheduling in real-time, allowing the system to adapt to different operating conditions and avoid resonance frequencies that cause noise, while maintaining simplicity through electronic control rather than complex mechanical adjustments

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If a solenoid valve is added to actively control the valve spool position, then fuel flow control precision is improved, but device complexity increases

Engineering Contradiction:
Improvefuel flow control precisionVSAvoidvalve assembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The solenoid actuator is nested within or directly coupled to the existing valve assembly structure. The solenoid's plunger or armature is integrated with the valve spool, allowing the control mechanism to be contained within the existing envelope. This nesting approach minimizes additional space requirements and reduces the perceived complexity while achieving precise flow control

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Enables fine-tuned fuel injection control, reducing noise and improving structural integrity by decoupling heat release and noise, while eliminating the need for additional hardware and providing robust operation even in power outages.

Implementation Method 1

The solenoid valve member is configured to control flow through the solenoid valve from the inlet to the outlet based on electrical power applied to a coil to apply a force on an armature of the solenoid valve

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 2

The valve spool is biased to a closed position by one or more biasing members of the scheduling valve assembly

Methodology Applied
Scientific EffectElastic force: Spring

Data Source

PatentEP4332361B1Proportional force modification of passive spool for control of simplex circuit of fuel nozzles
Publication Date: 2026.03.25 HAMILTON SUNDSTRAND CORP
  • EP4332361B1 patent drawingFigure 1
  • EP4332361B1 patent drawingFigure 2
  • EP4332361B1 patent drawingFigure 3

AI summary

A system includes an injector (102) including a scheduling valve assembly (104) and a nozzle (106) in fluid communication with the valve assembly (104). The scheduling valve assembly (104) is configured for regulation of flow from an inlet (108) of the injector to the nozzle (106). The injector (102) includes one fluid circuit (112) between the inlet (108) of the injector and a respective outlet of the nozzle (106). A solenoid valve (114) is connected in fluid communication with the scheduling valve assembly (104). The solenoid valve (114) is configured to adjust position of a hydromechanical valve spool (116) of the valve assembly (104).