Airfoil Sensor Housing Centrifugal Particle Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing moisture sensors in fluid media, such as those in hot-film air-mass meters, face contamination risks from particles and droplets, leading to inaccurate moisture content determination due to soiled membranes.
Innovation Solution
A sensor arrangement with a housing designed as an airfoil profile, featuring separate inlet and outlet openings, where the fluid medium flows counter to the main direction, creating a high static pressure area at the inlet and low pressure area at the outlet, facilitating centrifugal separation of particles and ensuring the membrane is protected from direct contact with contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a semipermeable membrane is used to protect the moisture sensor, then the sensor is protected from dirt particles, but the membrane becomes contaminated by water, dust, or oil mist leading to measurement errors
Solution Approach 1:
The sensor housing is divided into separate functional zones: a first opening for fluid medium intake, a second opening for moisture extraction, and a third opening for exhaust. The retention element is positioned to span only the first opening, creating distinct protection and measurement zones that prevent contamination while maintaining measurement accuracy.
Solution Approach 2:
The harmful function of the membrane (getting contaminated) is separated from the useful function (protecting the sensor). The retention element protects against particles at the first opening, while moisture is extracted separately through the second opening where no retention element is present, eliminating the contamination problem.
2Speed
If the sensor housing is designed with an airfoil shape to create pressure differential, then fluid medium flows faster at the outlet and centrifugal separation occurs, but the device complexity increases
Solution Approach 1:
The airfoil-shaped sensor housing performs multiple functions simultaneously: it creates the pressure differential needed for flow, provides centrifugal separation of particles and droplets, and defines the spatial arrangement of all openings and internal components. This multi-functionality reduces overall device complexity despite the sophisticated shape.
Solution Approach 2:
The airfoil shape with its curved surfaces creates favorable flow conditions for generating pressure differential and centrifugal forces. The curved geometry naturally guides the fluid medium through the housing, achieving particle separation and proper flow distribution without additional mechanical components.
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
This design effectively prevents contamination of the membrane, ensuring accurate moisture content measurement even in heavily contaminated environments by maintaining a clean air path past the protective membrane, thus enhancing the reliability of humidity sensing.
Implementation Method 1
The sensor housing is designed such that the fluid medium flows faster in the region of the outlet opening than in the region of the inlet opening
Implementation Method 2
The sensor housing essentially has the shape of an airfoil, wherein the inlet opening and the outlet opening are arranged on a top surface of the airfoil
Implementation Method 3
The sensor housing is designed such that the fluid medium flows faster in the region of the outlet opening than in the region of the inlet opening
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention proposes a sensor arrangement (10) for determining a moisture content of a fluid medium flowing in a main flow direction (12), in particular of intake air in an internal combustion engine. The sensor arrangement (10) has a sensor housing (14), in particular a plug-type sensor which is or can be introduced into a flow pipe, at least one moisture sensor (24), which is arranged in the sensor housing (14), for determining the moisture content of the fluid medium, and at least one retaining element (28). The retaining element (28) is at least partially permeable to moisture. The sensor arrangement (10) has an inlet opening (16) for passing moisture into the sensor housing (14), and the moisture sensor (24) and the retaining element (28) are arranged in the sensor housing (14) such that moisture can act on the moisture sensor (24) by means of the inlet opening (18) and the retaining element (28). The sensor arrangement (10) has at least one outlet opening (18), which is arranged separately from the inlet opening (16), for passing moisture from the sensor housing (14) into the flowing fluid medium.