Numerical study of geometrical effects on the performance of an H-type cylindrical resonant photoacoustic cell

Abstract

We have numerically studied the geometrical effects on the performance of an H-type cylindrical resonant photoacoustic cell, composed of one resonator and two symmetrical buffer cylinders, by performing simulations on the generation of acoustic waves in the cell. Here, the acoustic response (pressure), resonance frequency and quality factor are calculated for the cell performance, while the lengths and diameters of both resonator and buffer cylinders are considered for the geometrical parameters or dimensions. Our calculation solves linearized forms of the continuity equation, Navier-Stokes equation, energy equation, and equation of state using a finite element method under an assumption that the heat addition due to the laser passage and thus the variations in the velocity, pressure and temperature fields inside the cell are small enough. First, we performed a statistical analysis using a design of experiment method to evaluate the relative impacts of the cell dimensions on the acoustic response. Subsequently, we performed a parametric study to quantify the cell performance with the dimensional variations. Our results, along with the response surface methodology, provide guidance for a systematic design optimization of the cell for the best acoustic response. The approach in this study may be applied to the design of various types of resonant photoacoustic spectroscopy devices.