2013 Volume 13 Issue 1 Pages 35-39
In this paper, we present two types of CTA circuits which consist of a bridge circuit and a feedback circuit. One circuit uses only one operational amplifier and the ratio of the electrical resistance of the Wheatstone bridge is set to 10. Another one uses three operational amplifiers and two of them have bigger gain-band width product and slew rate, and its ratio of the electrical resistance of the Wheatstone bridge is set to 1. Velocity measurement results in a planet jet and a square jet show that there is no noticeable influence on the measured mean streamwise velocity and RMS value of the streamwise velocity fluctuation by the difference of the circuit in a CTA. However, it is found that the frequency response of each hot-wire anemometer is different and this causes the difference of the range of the non-dimensional streamwise wave number where obeys the reliable numerical energy spectrum derived by a LDIA (Lagrangian Direct-Interaction Approximation) theory.
