Airfoil Probe for Fluid Speed Measurement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing devices for measuring air speed in suction lines suffer from low measurement accuracy and risk of contamination, particularly in environments like mine ventilation where gases like methane are present.

Innovation Solution

A probe designed as a three-dimensional airfoil profile with measuring points on the front edge and side edges, minimizing vortex shedding and pressure fluctuations, ensuring high differential pressure measurements with reduced contamination risk and streamlined installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional probe design is used for measuring air speed, then the device can be installed in suction lines, but the measurement accuracy is low and contamination risk is high

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidcontamination risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The probe is designed with an airfoil profile featuring curved surfaces instead of sharp edges. The rounded leading edge and tapered trailing edge create streamlined geometry that reduces vortex formation and minimizes contamination risk while maintaining high measurement accuracy through optimized pressure differential detection

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention transitions from conventional two-dimensional probe cross-sections to a three-dimensional airfoil profile with specific thickness ratios. This dimensional enhancement allows the probe to better integrate with the fluid flow while maintaining measurement precision and reducing turbulence-induced contamination

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

2Measurement precision

If a Prandtl tube is used for dynamic pressure measurement, then the device structure is simple, but the pressure difference is not pronounced resulting in compromised measurement accuracy

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidprobe design complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The airfoil profile incorporates optimized geometric parameters including a thickness ratio of 0.3 to 0.5 and specific curvature radii at the leading and trailing edges. These parameter optimizations maximize the pressure differential between the leading and trailing edges, significantly improving measurement accuracy while maintaining a relatively simple probe structure

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If a probe with large dimensions is used to achieve adequate measurement, then measurement accuracy may improve, but the design effort and installation complexity increase considerably

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddesign effort
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

By optimizing the airfoil profile parameters including thickness ratio, curvature radii, and length-to-diameter ratio, the invention achieves high measurement accuracy with a compact probe design. The optimized geometry maximizes pressure differential per unit length, reducing the required probe size while maintaining or improving measurement precision and simplifying installation

Inventive Principle:
Principle #35Parameter changes

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 significantly enhances measurement accuracy and prevents contamination, allowing precise air speed determination in suction lines with minimal fluid disruption and probe influence, even in turbulent flows.

Implementation Method 1

a probe (3) which has at least two measuring points (4, 5) for measuring the differential pressure

Methodology Applied
Scientific EffectDifferential pressure measurement: Bernoulli Effect

Data Source

PatentEP2402722B1Device for measuring the speed of a fluid
Publication Date: 2016.06.29 WOELKE INDUSTRIEELKTRONIK GMBH
  • EP2402722B1 patent drawingFigure 1
  • EP2402722B1 patent drawingFigure 2

AI summary

The meter to measure the flow speed of a fluid, especially air in the suction channel of a mine ventilation system, has a probe (3) with at least two measurement points (4,5) for measurement of the different pressures. The probe has the shape of a spatial carrier surface profile with one measurement point at the leading edge (11) and the other at a side flank (12). The measurement points have entry openings into channels (6,7) to pressure sensors (8,9).