Abstract
A simple method is explained to measure the concentration and velocity simultaneously for the gas mixture (CO_2 預ir) turbulent flow by two hot-wire probes. By using a calibration map, the values of the instantaneous concentration and velocity can be determined from the voltages of two hot-wire probes with different overheat ratios (OHR) by digital data processing. This method does not require subtle adjustment of the OHR to achieve insensitivity to the CO_2 concentration, as in the past work by Chassaing (M駘ange turbulent de ganz inertes un jet tube libre, These Doc. Sciences 42, Inst. Nat. Poly. de Toulouse, 1979)(2). As an example of measurement, the data in a CO_2 jet in grid turbulence are presented. The experimental results for the centerline and radial distributions of the mean and r.m.s. values of mass fraction concentration and velocity, and axial scalar flux are consistent with previous other researcher's data.
