Rotatable Shrouds for Flow Sensor Vibration Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Sensor accuracy is compromised in fluid flow environments due to vibration and buffeting effects experienced by elongate probes, particularly in gas turbine engine applications where longer probes are exposed to airflow, leading to inaccurate flow velocity and turbulence measurements.

Innovation Solution

A sensor system featuring a mast with independently rotatable shrouds that adjust to reduce flow resistance by aligning with local fluid flow directions, utilizing aerofoil-shaped shrouds and a bearing system for low-resistance rotation, which reduces drag and vibration-induced errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the probe length is increased to reach deeper into the airflow region, then the measurement coverage is improved, but the vibration and buffeting of the probe increases, leading to reduced measurement accuracy

Engineering Contradiction:
Improveprobe lengthVSAvoidmeasurement accuracy
Core Design Contradiction:
Length of moving objectVSMeasurement precision

Solution Approach 1:

The probe structure is segmented into a core body and multiple shrouds that can rotate independently. This segmentation allows the shrouds to adjust their orientation to reduce vibration and buffeting effects while maintaining the extended reach of the probe into the airflow region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shrouds are made dynamically adjustable through rotation about the core body. This dynamic capability allows the probe to adapt its configuration in response to varying airflow conditions, reducing vibration and buffeting to maintain measurement accuracy while keeping the probe extended.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the probe is extended further into the airflow region, then the flow velocity and turbulence data collection capability is improved, but the adverse effect of vibration and buffeting increases in severity

Engineering Contradiction:
Improvedata collection capabilityVSAvoidvibration and buffeting
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The rotatable shrouds provide dynamic adjustment capability that allows the probe to maintain optimal orientation despite extended exposure to airflow. This reduces the severity of vibration and buffeting effects while preserving the enhanced data collection capability from deeper probe positioning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The shroud rotation mechanism converts the harmful effects of vibration and buffeting into useful information about airflow conditions. By allowing the shrouds to rotate and align with flow directions, the system transforms potential measurement errors into data about the actual flow field characteristics.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If fixed shrouds are used on the mast, then the structure is simpler, but the flow resistance cannot be optimized for varying fluid flow directions

Engineering Contradiction:
Improvestructure simplicityVSAvoidflow resistance
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The shrouds are designed to rotate independently about the core body, transforming a static structure into a dynamic one. This allows the shrouds to automatically align with varying fluid flow directions, optimizing flow resistance without requiring complex active control systems or multiple fixed configurations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The shrouds self-adjust their orientation in response to varying fluid flow directions through passive rotation. This self-service mechanism optimizes flow resistance automatically without requiring external control systems, maintaining structural simplicity while achieving adaptive performance.

Inventive Principle:
Principle #25Self-service

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 enhances measurement accuracy by minimizing flow resistance and vibration, allowing for more precise recording of flow velocity and turbulence data despite variations in fluid flow directions.

Implementation Method 1

each shroud is shaped so that, from at least one fluid flow direction, each shroud presents a different flow resistance in dependence upon its rotational orientation

Methodology Applied
Scientific EffectAerofoil: Aerofoil

Implementation Method 2

the rotational orientation of each shroud adjusts to reduce the flow resistance produced by the shroud to the fluid flow

Methodology Applied
Scientific EffectDrag reduction through alignment: Drag

Implementation Method 3

utilizing aerofoil-shaped shrouds and a bearing system for low-resistance rotation

Methodology Applied
Scientific EffectFriction reduction through bearing: Ball Bearing

Implementation Method 4

The sensor is adapted to measure a physical property of an air flow

Methodology Applied
Scientific EffectFlow detection:

Data Source

PatentEP3159661B1Flow sensor system with self-adjusting rotatable shrouds
Publication Date: 2018.12.26 ROLLS ROYCE PLC
  • EP3159661B1 patent drawingFigure 1~2
  • EP3159661B1 patent drawingFigure 3~4
  • EP3159661B1 patent drawingFigure 5~6

AI summary

A sensor system is disclosed comprising a sensor and a mast on which the sensor is mounted. The mast comprises a core body and a shroud, whereby the shroud is provided about the core body and the shroud is rotatable with respect to the core body under the influence, in use, of a fluid flow flowing past the shroud. The shroud is shaped so as, from at least one fluid flow direction, it presents a different flow resistance in dependence upon its rotational orientation. The rotational orientation of the shroud adjusts to reduce the flow resistance produced by the shroud to the fluid flow in response to the commencement of, or a change in the fluid flow direction to, one of the at least one fluid flow directions.