A New Generator of Pressure Pulsations With Wide Frequency and Amplitude

Time-varying pressure is measured in various fields and the calibration of pressure sensors for time-varying pressure is highly significant. The current piston-in-cylinder pressure pulsations generators generally operate at frequencies below 500 Hz. Due to the nonlinearity properties of gas compression and the limited displacement of the piston at high frequencies, generating sinusoidal pressure pulsations with large amplitudes becomes challenging when the frequency exceeds 500 Hz in a gaseous medium. This article proposes a new liquid-gas two-stage film generator with wide frequency range and amplitude range. First, the factors that affect the generation of high-frequency and high-amplitude pressure pulsations are analyzed. The primary factor is the limitation in piston displacement, resulting in small pressure amplitudes. A liquid-gas double-cylinder structure is proposed, which enhances the compression ratio by reducing the volume and outlet area of the secondary pneumatic cylinder. Second, the liquid-gas double-cylinder structure for pressure pulsation generators is further optimized. The symmetrical piston-in-cylinder generator produces pressure pulsations ranging from 45 to 500 Hz, while a liquid-gas two-stage film generator is utilized to generate pressure pulsations up to 2000 Hz. Experimental analyses were performed, indicating that the distortion of actual pressure pulsations is less than 12.5%, consistent with theoretical analysis. In the frequency range of 500-2000 Hz, the newly proposed pressure pulsation generator can reliably produce stable pressure pulsations at the specified frequencies.