Research on Sensitive Mechanism of Airflow Level Posture Sensor

In this paper, the sensitive mechanism of airflow level posture sensor is explained. By using the finite element method, the stream field by two point heat sources, when the two-dimensional enclosure is inclined, has been obtained by a series of procedure, such as model building, meshing, loads applying and equation solving. In the process ANSYS-FLOTRAN CFD program is applied .The numerical results are as follows: (1) In horizontal status, velocities of airflow at two point heat sources are equal, so currents of both hot wires are also equal. The output of the Bridge circuit is zero. (2)In tilting status, the velocity difference of airflow at two point heat sources changes with the tilt angle, which leads to changing of the current difference of both hot wires, the Bridge outputs a voltage signal of corresponding to the tilt angle. This calculated method provides a new road for optimization of airflow level posture sensor.