Filter Structure for Dynamic Pressure Measurement Resonance
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Solution Overview
Problem
Current systems for dynamic pressure measurements in environments like gas turbines face challenges due to resonance frequencies caused by long tubes, limited sensor access, and discrimination against low and high frequencies, leading to reduced measurement accuracy and bandwidth.
Innovation Solution
A filter structure is introduced that includes a restricting tube to attenuate higher-frequency dynamic pressure, allowing for improved dynamic pressure measurements by passing static and lower-frequency pressures while dampening higher-frequency pressures, thereby enhancing signal-to-noise ratio and measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a long tube is used to cool hot gases before reaching the sensor, then the gases are cooled successfully, but the bandwidth of the pressure measurement is reduced due to harmonic frequencies and resonance
Solution Approach 1:
A filter structure is introduced as an intermediary component between the long cooling tube and the pressure sensor. This filter structure includes a restricting tube with specific dimensions that allows low-frequency pressure signals to pass through while attenuating high-frequency resonance signals, thus preserving measurement bandwidth without compromising the cooling function
Solution Approach 2:
The filter structure changes the frequency characteristics of the pressure signal by using a restricting tube with carefully selected length and diameter. These dimensional parameters are optimized to create a low-pass filter effect, allowing desired low-frequency signals to pass while blocking unwanted high-frequency resonance from the long tube
2Measurement precision
If an infinite tube is used to remove resonance frequencies, then resonance frequencies are removed, but the tube requires long length and precise coiling which increases device complexity
Solution Approach 1:
The harmful resonance frequencies are extracted and removed from the pressure measurement system by introducing a separate filter structure. Instead of making the cooling tube itself complex (long and coiled), a distinct filter component is added that specifically targets and removes resonance frequencies while keeping the main tube configuration simple
Solution Approach 2:
The pressure measurement system is segmented into distinct functional components: the cooling tube for temperature control and the filter structure for frequency selection. This segmentation allows each component to be optimized independently - the tube for cooling efficiency and the filter for resonance removal - without requiring the tube to perform both functions complexly
3Speed
If standard pressure transducers are used to measure high frequency flow, then high frequency measurement capability is achieved, but the measurement accuracy is reduced by resonance and noise from the tube
Solution Approach 1:
The filter structure serves as an intermediary between the long cooling tube and the pressure transducer, cleaning the pressure signal by removing resonance frequencies and noise before they reach the sensor. This allows the transducer to accurately measure high-frequency flow variations without being contaminated by tube resonance
Solution Approach 2:
The filter structure converts the harmful resonance frequencies generated by the long tube into a beneficial low-pass filtering effect. By strategically placing the filter with appropriate dimensions, the resonance frequencies are attenuated while the desired high-frequency flow measurement capability is preserved, turning the tube's resonant behavior from a problem into a defined filter characteristic
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 filter structure effectively cancels or distorts lower-frequency pressures, allowing for accurate measurement of higher-frequency pressures with improved signal-to-noise ratio and reduced resonance-related distortions, enhancing measurement capabilities in environments with high static and dynamic pressures.
Implementation Method 1
The filter structure may filter, by the restricting tube, the input pressure to substantially pass an output pressure having the static pressure (PS), the lower-frequency dynamic pressure (PLD), and an attenuated higher-frequency dynamic pressure (PHD)
Data Source
AI summary
A method, device, or system is provided for improving dynamic pressure measurements. In one embodiment, a method comprises receiving, at a filter structure having a restricting tube, an input pressure having a static pressure (PS), a lower-frequency dynamic pressure (PLD) and a higher-frequency dynamic pressure (PHD); filtering, by the restricting tube, the input pressure to substantially pass an output pressure having the static pressure (PS), the lower-frequency dynamic pressure (PLD), and an attenuated higher-frequency dynamic pressure (PHD); and outputting, from the filter structure, the output pressure.