Study on Gas Flow Characteristics in Automobile Micro Gas Sensors

Article Study on Gas Flow Characteristics in Automobile Micro Gas Sensors Longkang Han 1, Feng Han 2,*, Ruquan Liang 2, Jianhui Shi 2, Dengbo Zhang 2, Yuanmei Song 2 and Kun Sun 3 1 School of logistics, Linyi University, Linyi 276000, China 2 School of Mechanical and Vehicle Engineering, Linyi University, Linyi 276000, China 3 School of Mechatronics Engineering, Anhui University of Science and Technology, Huainan 232001, China * Correspondence: [email protected] Received: 25 July 2024; Revised: 14 August 2024; Accepted: 22 August 2024; Published: 5 September 2024 Abstract: Micro gas sensors are integral to the automotive industry, particularly for monitoring the behavior of rarefied gases. The occurrence of inhomogeneous temperature gradients across microchannels can initiate gas flow, a principle that can be effectively utilized to develop micro gas sensors for automotive applications. This manuscript presents a novel microchannel design that incorporates quadrilateral sections with distinct temperature profiles. The characteristics of gas flow within this microchannel have been simulated numerically through the Direct Simulation Monte Carlo (DSMC) method, a sophisticated approach for such analyses. Subsequently, an optimization study is conducted to characterize the gas pumping properties of the microchannel. The results demonstrate that gas preferentially moves from a quadrilateral with lower temperature to one with higher temperature. The validity of this gas flow within the microchannel is confirmed. Notably, the gas flow velocity peaks at a Knudsen number of 3. This condition corresponds to a transitional flow regime, indicating that the microchannel’s gas pumping capability is most robust during this phase. Furthermore, it is observed that an increase in the quadrilateral aspect ratio leads to a reduction in gas flow velocity. These results can be applied to design micro gas sensors for various industry fields..