Hollow Probe Flow Separation for Constant Sensor Volume

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Solution Overview

Problem

Existing measuring devices for determining fluid medium parameters in vehicle climate control systems are influenced by variable air flow speeds and flap positions, leading to inhomogeneous and time-variable incident flows, which affect sensor accuracy.

Innovation Solution

A measuring arrangement with a probe device having a hollow body with a closed incident flow side and an open discharge flow side, featuring a partition wall that creates a constant volume flow for the sensor, independent of the fluid flow conditions, using a backflow mechanism to ensure accurate measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional sensor device is used in high-speed air flow (up to 10 m/s), then the device can operate in the fluid flow duct, but the sensor value becomes dependent on variable air flow speed and flap position, reducing measurement precision

Engineering Contradiction:

Improvesensor value accuracyVSAvoidair flow speed variability

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The hollow body is divided into separate inflow and outflow chambers by a partition wall, creating independent flow paths that prevent direct incident flow from affecting the sensor. This segmentation isolates the sensor from variable flow conditions while maintaining a controlled measurement environment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hollow body acts as an intermediary device between the high-speed air flow and the sensor. It captures a portion of the air flow through its inlet opening and provides a stabilized, constant volume flow to the sensor, mediating the harsh external flow conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the inlet and outlet openings are directly exposed to the air flow, then the device structure is simple, but pressure accumulation occurs at the openings, increasing volume flow variability and reducing measurement precision

Engineering Contradiction:

Improvevolume flow constancyVSAvoidprobe device structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The partition wall extends in the flow direction, creating a three-dimensional separation of flow paths. This spatial arrangement prevents pressure accumulation at openings by directing flows through separate chambers, adding a dimensional element to the flow management.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Measurement precision

If the sensor volume flow is dependent on incident flow speed, then the device can operate in varying climate control conditions, but the sensor accuracy decreases due to time-variable flow influence

Engineering Contradiction:

Improveair quality measurement accuracyVSAvoidoperation under varying climate control conditions

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The hollow body automatically maintains a constant volume flow through its geometric design and flow separation characteristics, without requiring external regulation or control systems. The backflow mechanism self-regulates to provide stable sensor flow conditions across varying operating conditions.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The device changes the flow parameters from variable high-speed incident flow to constant volume flow at the sensor. The hollow body transforms the incident flow conditions through its geometric design, converting speed-dependent flow into a stable, regulated flow regime suitable for accurate measurement.

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 provides a constant sensor volume flow, enhancing accuracy by avoiding direct interference between the inlet and outlet openings and ensuring effective separation of the fluid flow, thus allowing for precise measurement of air quality parameters like fine dust concentration without requiring regulation.

Implementation Method 1

an outer contour generating a flow separation on the discharge side for generating a backflow

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Implementation Method 2

a partition wall dividing the cavity into a fluid inflow chamber and a fluid outflow chamber

Methodology Applied

Scientific EffectPhysical separation:

Data Source

PatentUS11385142B2Measuring arrangement for determining a parameter of a fluid medium flowing through a fluid flow channel and fluid flow channel having such a measuring arrangement

Publication Date: 2022.07.12 AUDI AG

AI summary

A measuring arrangement for determining at least one parameter of a fluid medium flowing through a fluid flow duct. The measuring arrangement includes a probe device designed to be arranged in the flowing medium as a hollow body having an incident flow side closing the cavity of the hollow body, an open discharge flow side, an outer contour, which generates a flow separation on the discharge flow side, for generating a backflow, and a partition wall dividing the cavity into a fluid inflow chamber and a fluid outflow chamber, wherein the fluid inflow chamber includes an inlet opening and the fluid outflow chamber includes an outlet opening.