Research on structural optimization and performance improvement of photoacoustic cells

This paper investigates the impact of resonator and buffer chamber designs on photoacoustic cells' (PACs) performance in gas detection systems. Specifically, we analyze how the structure of the resonator affects resonant frequency characteristics and acoustic pressure signal amplitude while examining how the structure of the buffer chamber influences airflow velocity and flow stability. As the critical component of photoacoustic spectroscopy (PAS) systems, the design of the PAC directly determines the system's detection accuracy and sensitivity. While traditional designs predominantly employ cylindrical structures for resonators and buffer chambers, these designs present limitations in acoustic field optimization and gas flow regulation. To address these constraints, we utilize COMSOL Multiphysics software, employing its thermo-viscous acoustics (TVA) and laminar flow modules to simulate acoustic and flow fields for innovative structural designs, including conical resonators, round-table buffer chambers, and spherical buffer chambers. The simulation results demonstrate that the conical resonator significantly enhances photoacoustic (PA) signal intensity compared to conventional cylindrical resonators, primarily through its geometric acoustic wave-focusing effect. Furthermore, the round-table and spherical buffer chambers effectively mitigate airflow velocity and turbulence-induced noise by optimizing gas flow pathways, thereby reducing PA signal interference. Notably, the innovative gradient geometry design of the round-table buffer chamber achieves dual optimization: it enhances gas flow stability while simultaneously facilitating miniaturization of the PAC. The structural advancements collectively contribute to more compact system configurations. The findings provide crucial insights for optimizing performance and miniaturizing PAS gas detection systems, offering substantial potential for practical applications across various fields.