Abstract
The constant voltage anemometer (CVA) was used to calibrate a hot wire over a wide overheat range. Instead of the output voltage (E) of the anemometer which is normally used, at each test point a quantity represented by “pdr” equal to the ratio of power dissipated in the hot wire (Pw) and the associated difference in the heated resistance of the hot wire (Rw) and its resistance (Ra) at the ambient fluid temperature is calculated. It is shown that the calibration curves so obtained with pdr=Pw/(Rw−Ra) as the output variable instead of E can be represented by a single calibration equation covering the wide overheat range. Overheat variation is equivalent to allowing an ambient temperature change of the fluid at a given setting. It demonstrates that this approach can be used to cover measurements using the hot wire with fluid temperature drifts without using a second hot wire for temperature corrections and without any temperature calibration. The calibration data was then applied to measure the unsteady flow in the near orifice region of synthetic jets with very good results. The measurements confirm the computational predictions that show that although there is flow reversal, over a cycle of oscillation, the synthetic jet actuator spends most of the cycle ejecting rather than ingesting fluid.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.