An experimental investigation of the destabilising effects of discrete suction perforations for laminar flow control applications was performed. This research was aimed at investigation of the flow physics of large arrays of discrete perforated suction arrays in globally two-dimensional flows. This research also investigated the effect of varying perforation size, free-stream velocity and suction volume flow rate on the amplification and attenuation of excited travelling waves in a two-dimensional laminar flow. It was found that instead of creating local instabilities that destabilise all frequencies, strong suction had the effect of introducing low frequency disturbances while attenuating naturally produced and excited travelling waves for all test cases considered. If the suction was sufficiently strong these low frequency disturbances would appear to dominate over the stabilising effect of suction (on the natural and excited modes). Possible explanations for these disturbances include viscous or acoustic disturbances located within the suction system. Future experiments will attempt to isolate the effect of the plenums to determine if this is the source of these low frequency disturbances.
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