General Analysis of the Operation of a Sampling Probe for Velocity and Concentration Measurements in Two-Phase Flows

Abstract: A potential flow model has been used for the theoretical prediction of the gas velocity field around a sampling probe. Results given by a proper numerical solution have been compared in a limit condition with those obtained from experimental measurements, showing a good agreement, in view of the number of simplifying hypoteses assumed and of the uncertainties due to the small scale experimental situation. The isokinetic calibration of a specimen probe, here reported, puts into evidence the practical difficulties to achieve isokinetic operation; then calibration curves for concentration ratios in anisokinetic operation have to be used, given here as obtained from particle trajectory calculation. Finally, the capability of anisokinetic operation to give more information, if the particle velocity near the probe intake is also measured, is emphasized, on the base of the particle approach velocity analysis.