Dynamic pressure generator for dynamic calibrations at different average pressures based on a double-acting pneumatic actuator

Abstract

The ability to conduct dynamic calibrations of pressure sensors at different average pressures is very important because the dynamic properties of pressure sensors also depend on the value of the average pressure during the pressure pulsations. The main limitation of periodic dynamic pressure generators is the difficulty in achieving sinusoidal pulsations at higher amplitudes and frequencies in a gaseous medium due to the nonlinearities that result from the physical gas dynamics. This paper presents a newly developed dynamic pressure generator based on a double-acting pneumatic actuator in which the piston is driven by an electrodynamic shaker. In order to minimize the static preload of the shaker, which is due to the pressure acting on the piston, and therefore to enable the generation of larger pressure pulsations at different average pressures with the same excitation force, the cylinder chambers above and below the piston are pressurized with the same initial static gas pressure. As the dynamic characteristics of the dynamic pressure generator are also defined by the properties of the piston and both the cylinder chambers, the actuator dimensions were optimized with the help of mathematical modeling. In order to demonstrate the capabilities and limitations of the developed dynamic pressure generator, both mathematical and experimental analyses were performed.