Performance optimisation of a sensing chamber using fluid dynamics simulation for electronic nose applications

Abstract

The sensor chamber plays a significant role in order to improve the performance of an electronic nose in terms of stability, repeatability, reproducibility, and sensitivity. Fluid dynamics simulations of six different configurations of 3D sensing chambers are presented to facilitate the efficient design of an electronic nose system comprising 64 sensor arrays. Numerical simulations were carried out to investigate the gas (zero air) flow behaviour inside these chambers under steady-state conditions for velocities ranging from 0.1 to 2 m/s using ANSYS software. Design optimisation was performed in terms of area coverage, velocity, and mass fraction. The results show that the area coverage and mass fraction distribution increase with flow velocity. The sensor chambers achieved more than 70% flow coverage over the sensors at a velocity beyond 0.7 m/s. In further chamber designs, four baffles were introduced at different positions in a two inlet and one outlet chamber model to enhance the performance of the chamber. The effect of baffle positions in the flow distribution was investigated through numerical simulations. Chamber designs with the introduction of baffles achieved a maximum mass fraction. Thus, the insertion of baffles improved the area coverage and mass fraction. In addition, to show the real-time applicability further simulations were performed in the optimised sensor chamber.

Development of a Low-Cost Electronic Nose with an Open Sensor Chamber: Application to Detection of Ciboria batschiana

“…Another inspiration of nasal structure, for the construction of a bionic sensor chamber, was reported by Villarreal et al [ 26 ] and Chang et al [ 43 ], in which the effective transport of odor to sensors and exhalation of gas from the chamber was achieved. Dohare et al [ 44 ] reported a fluid dynamics simulation of cuboidal electronic nose sensor chambers with three different three-dimensional models with single and multiple inlets and outlets. Furthermore, they studied the influence of the introduction of four baffles directing the flow of the air in the chamber.…”

Physical Confounding Factors Affecting Gas Sensors Response: A Review on Effects and Compensation Strategies for Electronic Nose Applications

“…All the authors [27,94,[98][99][100][101][102][103][104][105][106][107] focusing on the sensors' chamber design agree that, inside the chamber, stable and uniform conditions should be reached as soon as possible. To ensure stable and uniform conditions, laminar flow is required in the chamber, with no stagnant or recirculating zones, which may result in a different exposure of the sensors to the target gas.…”

“…To obtain a better and more reproducible response, the gas flow in the chamber should be laminar and as homogeneous as possible, meaning that all the sensors should be simultaneously exposed to the same gas flow [27,94,[98][99][100][101][102][103][104][105][106][107];…”