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.

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Purpose The purpose of this paper is to understand the effect of airflow dynamics on vortices for different flow rates using the human nose three-dimensional model. Design/methodology/approach Olfaction originates with air particles travelling from an external environment to the upper segment of the human nose. This phenomenon is generally understood by using the nasal airflow dynamics, which enhances the olfaction by creating the vortices in the human nose. An anatomical three-dimensional model of the human nasal cavity from computed tomography (CT) scan images using the MIMICS software (Materialise, USA) was developed in this study. Grid independence test was performed through volume flow rate, pressure drop from nostrils and septum and average velocity near the nasal valve region using a four computational mesh model. Computational fluid dynamics (CFD) was used to examine the flow pattern and influence of airflow dynamics on vortices in the nasal cavity. Numerical simulations were conducted for the flow rates of 7.5, 10, 15 and 20 L/min using numerical finite volume methods. Findings At coronal cross-sections, dissimilar nasal airflow patterns were observed for 7.5, 10, 15 and 20 L/min rate of fluid flow in the human nasal cavity. Vortices that are found at the boundaries with minimum velocity creates deceleration zone in the nose vestibule region, which is accompanied by flow segregation. Maximum vortices were observed in the nasal valve region and the posterior end of the turbinate region, which involves mixing and recirculation and is responsible for enhancing the smelling process. Practical implications The proposed analysis is applicable to design the sensor chamber for electronic noses. Originality/value In this paper, the influence of airflow dynamics on vortices in the human nasal cavity is discussed through numerical simulations.

Multipath routing plays an important role in communication networks. It can increase the effective bandwidth between pairs of vertices, avoid congestion in a network and reduce the probability of dropped packets. In this paper, we built model for vertex-disjoint paths problem and then proposed algorithm for finding the shortest pair of vertex-disjoint paths. We consider in this paper the shortest-path problem in networks in which the length (or weight) of the edges are considered. We present algorithms for finding the shortest-path. In more restricted transit. Furthermore, we can extend this algorithm to find any k disjoint paths whose sum-weight is minimized.