Double probe recovery temperature Anemometry

Abstract

It is known that the temperature rendered by temperature probes positioned within an airflow depends on the thermodynamic temperature, the external flow velocity, the specific heat of the fluid, and the recovery factor of the probe. The said dependence is essential for the external velocity measurement by the method of Recovery Temperature Anemometry (RTA). Even if both the recovery factor of the probe and isobaric heat capacity are known, one also has to know the external flow velocity for the evaluation of the thermodynamic temperature or, the thermodynamic temperature for the evaluation of the flow velocity. This means there are two unknown properties in real-time measurements – thermodynamic temperature and velocity. This article deals with the possible solution to the mentioned problem. By the use of two probes with different recovery factors, the need for knowing the thermodynamic temperature is eliminated, so that a combination of two temperature probes with different recovery factors can be used for the velocity measurement.