The applicability of a deconvolution Kalman filtering approach is assessed for the force measurements on a flat plate undergoing a revolving motion, as an alternative procedure to correct for test setup vibrations. The system identification process required for the correct implementation of the deconvolution Kalman filter is explained in detail. It is found that in the presence of a relatively complex forcing history, the DK filter is better suited to filter out structural test rig vibrations than conventional filtering techniques that are based on, for example, low-pass or moving-average filtering. The improvement is especially found in the characterization of the generated force peaks. Consequently, more reliable force data is obtained, which is vital to validate semi-empirical estimation models, but is also relevant to correlate identified flow phenomena to the force production.

The flow passing through a sharp-edged orifice is studied using two experimental techniques over a pipe Reynolds number range of 4000 to 27000. The flow separates at the orifice inlet and is accelerated through its hole in the form of a confined jet. For a given orifice, the mean reattachment length is found to remain fairly independent of the inflow Reynolds number. Velocity and pressure fluctuations attain peak values in regions lying upstream of the mean reattachment point. Under the conditions tested, the orifice jet shows a low frequency flapping motion which was observed to occur at a Strouhal number 0:02 based on the orifice jet velocity and the difference in internal diameters of the pipe and orifice.