Fluid Velocity Sensor Using Temperature-Dependent Resonance
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Solution Overview
Problem
Existing flow sensor systems are unable to accurately measure fluid velocity under non-steady flow conditions, as they rely on equations that do not account for time-varying fluid flows, limiting their applicability in systems with dynamic fluid patterns such as respiration and medical implants.
Innovation Solution
A sensor system that uses a heating element to transfer heat to the fluid, making the primary electronic circuit's resonance frequency temperature-dependent, allowing for accurate velocity measurement through a grid dip oscillator, which can wirelessly determine the resonance frequency and thus the fluid velocity, regardless of flow steadiness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a differential pressure sensor system is used to measure fluid velocity, then measurement is possible under steady flow conditions, but it fails to provide accurate measurement under non-steady flow conditions
Solution Approach 1:
The patent changes the measurement parameter from differential pressure to temperature. By measuring the temperature of the fluid instead of pressure differential, the system can accurately measure velocity in both steady and non-steady flow conditions. The temperature measurement is achieved through a temperature-dependent resonance frequency of an electronic circuit.
Solution Approach 2:
The patent replaces the mechanical pressure sensing system with an electronic resonance frequency-based temperature sensing system. Instead of using pressure sensors and mechanical components to measure flow velocity, the invention uses an electronic circuit whose resonance frequency changes with temperature, providing a more versatile measurement approach.
2Measurement precision
If a temperature-dependent resonance frequency circuit is used to measure fluid velocity, then accurate measurement in both steady and non-steady conditions is achieved, but the device complexity increases
Solution Approach 1:
The electronic resonance frequency circuit serves multiple functions: it acts as both the temperature sensor and the measurement transducer. The same circuit that generates the resonance frequency also provides the measurement signal, eliminating the need for separate temperature sensing components and reducing overall system complexity despite the sophisticated measurement principle.
Solution Approach 2:
The electronic circuit uses its own temperature-dependent resonance frequency as the measurement parameter. The circuit essentially measures its own temperature state through its resonant behavior, eliminating the need for external temperature sensors or additional measurement components.
3Ease of operation
If wireless flow measurement is implemented in medical implants, then patient comfort and infection risk are improved, but measurement reliability under pulsating flow conditions deteriorates
Solution Approach 1:
The patent changes from pressure-based measurement to temperature-based measurement using resonance frequency. This parameter change enables reliable measurement under pulsating flow conditions because temperature changes in response to flow velocity regardless of whether the flow is steady or pulsating, providing consistent measurement reliability in medical implant applications.
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
Enables accurate measurement of fluid velocity in both steady and non-steady conditions, suitable for applications like respiration systems and medical implants, with the ability to operate wirelessly and be reused, reducing complexity and costs.
Implementation Method 1
a temperature of at least a part of the primary electronic circuit is determined by heat transferred from the heating element to the fluid flowing through the channel
Implementation Method 2
a primary electronic circuit having a primary resonance frequency, which primary resonance frequency is temperature dependent
Implementation Method 3
the transducer arrangement comprises a grid dip oscillator for determining the primary resonance frequency of the primary electronic circuit
Implementation Method 4
a heating element for heating the fluid, wherein the heating element is provided with a predetermined level of power during operation
Data Source
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AI summary
The invention relates to a sensor system (102) for measuring a velocity of a fluid (110) flowing through a channel (108), comprising a heating element (104) for heating the fluid, wherein the heating element (104) is provided with a predetermined level of power during operation. The sensor system (102) furthermore comprises a primary electronic circuit (114) having a primary resonance frequency, which primary resonance frequency is temperature dependent. Herein the temperature of the primary electronic circuit (114) is determined by heat transferred from the heating element (104) to the fluid (110) flowing through the channel (108). In addition, the sensor system (102) comprises a transducer arrangement (126) configured for generating a measurement signal (128) indicative for the velocity of the fluid (110) flowing through the channel (108). Herein, the measurement signal (108) is based on the primary resonance frequency.