Passively Orientable Pressure Probe for Variable Airflow Angles

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Solution Overview

Problem

Existing pressure probes used in aircraft engines suffer from measurement inaccuracies due to variations in the angle between the probe and the incoming airflow, leading to suboptimal stagnation pressure measurements, especially in scenarios where airflow angles vary significantly.

Innovation Solution

A pressure probe design featuring a movable member that adjusts its orientation relative to the airflow, using an orientation section to align itself parallel to the flow, minimizing drag and ensuring optimal stagnation pressure measurement across a wide range of angles without active actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional Pitot probe or Kiel head probe is used for measuring stagnation pressure, then the measurement is accurate when the probe is aligned with the airflow, but the measurement accuracy deteriorates when the angle between the probe and airflow exceeds the acceptance range

Engineering Contradiction:
Improvestagnation pressure measurement accuracyVSAvoidacceptance range of airflow angles
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The probe incorporates a movable member that can dynamically adjust its orientation relative to the airflow direction. The movable member, which includes the engagement section with the opening, is capable of rotating about a center of rotation to change the angle between the probe's opening and the airflow, thereby maintaining optimal measurement conditions across varying airflow angles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The probe utilizes the airflow itself to automatically orient the movable member into the correct position. The aerodynamic forces generated by the flowing air cause the movable member to rotate and align itself with the airflow direction, eliminating the need for external actuators or complex control systems while ensuring accurate measurement positioning.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If the probe is fixed in position to maintain alignment with airflow, then measurement accuracy is maintained, but the device cannot adapt to changing airflow directions

Engineering Contradiction:
Improvestagnation pressure measurement accuracyVSAvoidability to handle varying airflow angles
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The probe transforms from a static structure to a dynamic one by incorporating the movable member that can rotate about a center of rotation. This movable section, including the engagement section with the pressure-sensing opening, adjusts its angular position in response to airflow direction changes, allowing the probe to maintain measurement accuracy across a wide range of airflow angles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The probe employs passive aerodynamic orientation where the airflow itself provides the forcing mechanism to position the movable member. The shape and positioning of the movable member create aerodynamic moments that automatically align the opening with the airflow direction, enabling the probe to self-adjust without external control systems.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the movable member is designed with a large orientation section to improve airflow capture, then the ability to orient with airflow increases, but the complexity of the device increases

Engineering Contradiction:
Improveairflow orientation capabilityVSAvoidprobe structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The probe is divided into distinct functional segments: a static member providing structural support and housing, and a movable member containing the engagement section with the opening and the orientation section. This segmentation allows the movable portion to rotate independently for orientation while the static portion maintains structural integrity and provides mounting features.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The static member includes a spherical surface that engages with the movable member, providing a simple yet effective rotation mechanism. The spherical geometry allows for smooth rotational movement about a fixed center point while maintaining compact dimensions, reducing overall device complexity compared to more complex articulation mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 probe achieves improved measurement accuracy by passively aligning with the airflow, maintaining high recovery ratios and reducing measurement errors, even in conditions with varying airflow angles.

Implementation Method 1

the movable member movable relative to the static member about a center of rotation of the movable member, the movable member having a central axis, the movable member having an engagement section matingly engaged to the front face to slide against the curved surface

Methodology Applied
Scientific EffectAerodynamic force: Drag

Implementation Method 2

the orientation section defining an external surface exposed to the flow and facing away from the central axis

Methodology Applied
Scientific EffectFluid force: Force

Data Source

PatentEP4343120B1Passively orientable pressure probe
Publication Date: 2026.05.20 PRATT & WHITNEY CANADA CORP
  • EP4343120B1 patent drawingFigure 1
  • EP4343120B1 patent drawingFigure 2
  • EP4343120B1 patent drawingFigure 3

AI summary

An aircraft engine (10) has a pressure probe (30) having: a static member (31) having a front face (31A) and a back face (31B), an inlet (311) and an outlet (310) fluidly connected to the inlet (31I), the front face (31A) defining a curved surface (31C); a movable member (32) movably engaged to the static member (31) and movable relative to the static member (31) about a center of rotation (R0), the movable member (32) having a central axis (A), the movable member (32) having an engagement section (35) matingly engaged to the front face (31A) to slide against the curved surface (31C), the engagement section (35) having an opening (35A), and an orientation section (37) protruding from the engagement section (35) and located rearward of the center of rotation (R0), the orientation section (37) defining an external surface (37A) exposed to the flow (Fa), wherein the movable member (32) is movable relative to the static member (31) as a result of a force imparted by the flow (F0) on the external surface (37A).