Flow Regulator Damping with Flowing Orifices for Temperature Stability

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Solution Overview

Problem

Existing fluid flow regulators are sensitive to temperature variations due to laminar leak path damping, which affects viscosity, and non-flowing orifice damping provides no damping at zero velocity but over-damps during large disturbances, leading to issues like high-frequency oscillations and equipment interference in aircraft applications.

Innovation Solution

A flowing orifice damping arrangement that maintains consistent damping independent of amplitude, using larger diameter passages to reduce contamination and leakage sensitivity, and eliminates the need for check valves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laminar leak path damping is used, then linear damping over full valve velocity range is achieved, but damping becomes sensitive to temperature variations due to viscosity changes

Engineering Contradiction:
Improvedamping consistencyVSAvoidtemperature sensitivity
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent changes the damping mechanism from laminar flow (viscosity-dependent) to turbulent flow through orifices (velocity-dependent). By using small orifice openings that create turbulent flow conditions, the damping force becomes proportional to the square of valve velocity rather than being proportional to fluid viscosity, thereby eliminating temperature sensitivity while maintaining consistent damping across the full velocity range.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If non-flowing orifice damping is used, then temperature sensitivity is reduced, but damping is proportional to square of valve velocity causing no damping at zero velocity and over-damping during large disturbances

Engineering Contradiction:
Improvetemperature sensitivityVSAvoiddamping consistency
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent transitions from a static non-flowing orifice to a dynamic flowing orifice system where the orifice is positioned within the flow path. This allows the orifice to remain submerged in flowing fluid, creating a flowing orifice damping arrangement that provides consistent damping forces proportional to valve velocity squared while maintaining temperature insensitivity. The dynamic positioning ensures the orifice operates effectively across all valve positions.

Inventive Principle:
Principle #15Dynamics

3Reliability

If smaller orifice passages are used for damping, then damping effectiveness is improved, but resistance to contamination decreases and leakage sensitivity increases

Engineering Contradiction:
Improvedamping effectivenessVSAvoidcontamination resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent resolves the contradiction between small orifice size and contamination resistance by transitioning from a single small orifice to multiple larger orifices arranged in parallel. This dimensional change from one small opening to multiple larger openings maintains the same total flow restriction (damping effectiveness) while increasing the surface area and reducing clogging susceptibility. The parallel arrangement provides redundancy against contamination.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution provides temperature-insensitive damping, reduces leakage sensitivity, improves contamination resistance, and maintains consistent damping across varying flow rates without additional pump draw, addressing the limitations of prior damping methods.

Implementation Method 1

Non-flowing orifice damping exhibits less temperature sensitivity than valves using laminar leak path damping. However, non-flowing orifice damping is proportional to the square of valve velocity.

Methodology Applied
Scientific EffectTurbulent flow: Turbulence

Implementation Method 2

Laminar leak path damping can provide linear damping over the full range of valve velocities. However the damping is proportional to the kinematic viscosity of the fluid being regulated, therefore the damping is sensitive to temperature variations of the fluid media.

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 3

A spring applies a force to the valve in response to a pressure differential between the fluid inlet and the fluid outlet

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3140532B1Regulator flow damping
Publication Date: 2025.07.02 WOODWARD INC
  • EP3140532B1 patent drawingFigure 1~3
  • EP3140532B1 patent drawingFigure 4~5
  • EP3140532B1 patent drawingFigure 6~7

AI summary

The subject matter of this specification can be embodied in, among other things, a method that includes providing a fluid at a fluid inlet fluidically connected to an input fluid path, providing a fluid outlet fluidically connected to an outlet fluid path, fluidically connecting the inlet fluid path to the outlet fluid path through a valve, fluidically connecting the inlet fluid and the outlet fluid through a bypass fluid path in parallel with the valve, flowing the fluid from the inlet fluid path to the outlet fluid path through the valve and the bypass fluid path at a regulated fluid flow rate, restricting fluid flow in the bypass fluid path with a first orifice, restricting fluid flow in one of the fluid inlet path or the fluid outlet path with a second orifice, and providing the fluid at the fluid outlet at an outlet fluid flow rate.