Pressure-Sensitive Paint Measurement Using Stable Sinusoidal Pressure Waves
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Solution Overview
Problem
Existing measuring devices for dynamic characteristics of pressure sensitive paint (PSP) face challenges in achieving high-frequency precision for amplitude and phase characteristics of pressure frequency due to pressure instability, wave reflection, and frequency multiplication, limiting their ability to capture precise pressure dynamics.
Innovation Solution
A measuring device comprising a PSP sample wafer, dynamic pressure sensor, oscilloscope, light source, photomultiplier tube, bandpass filter, loudspeaker, and power amplifier, which generates continuous sinusoidal pressure waves with high precision, allowing for precise capture of amplitude and phase characteristics by synchronously recording light and pressure signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an acoustic standing wave tube is used to generate continuous sinusoidal pressure, then pressure stability is improved, but the tube length must be increased to generate lower frequency pressure waves, resulting in pressure loss and measurement limitations
Solution Approach 1:
The patent replaces the acoustic standing wave tube mechanism with a loudspeaker-based system that directly generates sinusoidal pressure waves. The loudspeaker converts electrical sinusoidal signals into mechanical pressure variations, eliminating the need for long acoustic tubes and their associated pressure losses while maintaining pressure stability and enabling precise frequency control.
Solution Approach 2:
The patent changes the fundamental parameter of pressure generation from acoustic resonance in a tube to direct electromagnetic-to-mechanical conversion via a loudspeaker. This allows independent control of frequency and amplitude parameters without being constrained by tube length, enabling precise measurement of PSP dynamic characteristics across a wide frequency range with 0.01 Hz precision.
2Power
If a shock tube is used to compress air continuously, then pressure waves can be generated, but the device cannot measure amplitude frequency characteristics and phase frequency characteristics of continuously-changed pressure
Solution Approach 1:
The patent employs periodic sinusoidal pressure waves generated by a loudspeaker driven by a signal generator. This periodic action allows for continuous measurement of amplitude frequency characteristics and phase frequency characteristics, as the sinusoidal waveform provides well-defined frequency and phase parameters that can be precisely measured and analyzed throughout the test frequency range.
3Productivity
If a fluid oscillator is used to generate pulsating airflow, then dynamic pressure can be applied, but the pulsating airflow is not a standard sinusoidal wave and pressure stability is difficult to guarantee
Solution Approach 1:
The patent replaces the fluid oscillator's complex mechanical airflow generation with a loudspeaker-based system that directly produces controlled sinusoidal pressure waves. The loudspeaker's electromagnetic actuation provides precise control over the pressure waveform, ensuring it maintains a standard sinusoidal shape with stable amplitude and frequency, thereby guaranteeing pressure stability while maintaining productivity.
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 device enables precise capture of amplitude and phase characteristics of pressure frequency with a frequency precision of 0.01 Hz, reduces pressure loss, and maintains high stability with a simple structure using common equipment.
Implementation Method 1
When being excited by light with a specific wavelength, the photosensitive molecules in the paint get energy from the originally stable ground state
Implementation Method 2
A detection end of the photomultiplier tube is provided with the bandpass filter, and an output end of the photomultiplier tube is connected to the input end of the oscilloscope
Implementation Method 3
The loudspeaker, the power amplifier and the signal generator are connected in sequence
Implementation Method 4
A detection end of the photomultiplier tube is provided with the bandpass filter
Data Source
AI summary
The disclosure discloses a measuring device for dynamic characteristics of pressure sensitive paint, including a PSP sample wafer, a dynamic pressure sensor, an oscilloscope, a light source, a photomultiplier tube, a bandpass filter, a loudspeaker, a power amplifier, and a signal generator. The disclosure further discloses a measuring method for dynamic characteristics of pressure sensitive paint. The disclosure has the following beneficial effects: by using the measuring device disclosed by the present disclosure, the continuous sinusoidal pressure wave with any frequency can be generated, and has the frequency precision that does not exceed 0.01 Hz, an optical path is not shielded, high stability is achieved, and the amplitude and phase characteristics of the pressure frequency of the PSP can be precisely captured.