Averaging of particle data from phase Doppler

A novel post-processing algorithm is proposed to correct statistical bias observed in the treatment of time seriesobtained by a phase Doppler anemometer (PDA) at flow locations with variable particle velocity and concentration.Extensive properties of each validated particle are weighted with their inverse measuring (validation) volume to accountfor the procedure of particle sampling and fluctuations in the particle concentration. To compensate for the short characteristiclength of the validation volume, the properties of particles are expressed by properties of fields of particle groups,using a local averaging time. A window shift and a decorrelation scheme are applied on the fields to increase their frequencyresolution. This algorithm has been tested on numerical time series, provided by an Eulerian/Lagrangian code representinga gas/solids flow past a bluff body. Moments and spectral estimates of concentration and velocity of particlegroups were successfully validated by the numerical simulation using the PDA data algorithm and control volume averaging.The control volume was much larger than the PDA validation volume, but the centre positions of the two volumeswere identical