Simulation for velocity measurement with thermal micro-flow sensors

The measurement technology of fluid flow for micro-flow sensors has been applied in biomedicine, aerospace, the automobile industry and heat exchangers. A numerical study has been conducted to investigate the laminar flow and heat transfer behaviors of micro-channels for velocity measurement of micro-flow sensors. In this study, one method is used to calculate the heat transfer of the fluid flow in the micro-channels, and the difference of temperatures on the upper and bottom walls, which can be used to determine the velocity of fluid in the micro-channels. Another method consists of heating the bottom wall of the micro-channels, to observe the buoyancy effect induced by the difference in temperature or the secondary flow phenomenon, which can also result in very low fluid flow. We used the commercial code CFX4.1C as a numerical arithmetic unit with the finite volume method is used to simulate the equations for the three-dimensional, compressible and laminar flow.