基于声弛豫频率的可激发气体压强合成算法

An Algorithm for Synthesizing Excitable Gas Pressure Based on Sound Relaxation Frequency

声弛豫频率是声吸收谱峰值点的频率,包含可激发气体成分、环境温度和压强信息.利用声弛豫频率线性正比气体压强的特性,提出一种通过两频点声吸收系数和声速测量值计算声弛豫频率,并通过查表方式合成气体压强的算法.算法的声弛豫频率测量误差具有随声测量值误差线性变换的特性,且当两频点的声吸收测量误差相等时,压强的合成误差为零.对于一定温度下的甲烷及其混合气体,仿真计算证明算法的有效性和声测量误差的稳健性.提供一种简单、稳健性好、可实时连续在线检测可激发气体腔体压强的声学方法.

Sound relaxation frequency is frequency of peak point in sound absorption spectrum,which contains information of gas composition,ambient temperature,and pressure in excitable gases.With characteristics of sound relaxation frequency is linearly in proportion to gas pressure,we propose an algorithm for synthesizing gas pressure by acoustic relaxation frequency calculated with absorption coefficients and sound speeds at two frequencies.Measurement error of sound relaxation frequency is proportional to acoustic measurement error.Specially,as sound absorption measurement errors at the two frequencies are equal,error of synthesized pressure is zero.For methane and its mixtures at a certain temperature,simulation results demonstrate effectiveness of the algorithm and its robustness to acoustic measurement errors.Thus,a novel acoustic method,which is simple,robust,and capable of on-line to detect pressure of excitable gas vessel,is provided.