Department of Civil and Hydraulic Engineering, Indian Institute of Science, Bangalore,
Two types of impact probes “Pitot Sphere” and “Swept Back Edge Impact Probe” measuring the three-dimensional flout pattern, developed by authors have been discussed in this paper. Theoretical calibration curves have been evaluated for both the probes and are compared with the experimental calibration curves. The experimental method used by the authors to calibrate the instruments is different from that of usual towing tank method used by Shukry (14). The calibration curves obtained by this way for Pitot sphere were compared with the calibration curves obtained by Shukry from towing tank method and were found agreeing closely within the experimental limitations. The other instrument is an improved version over the Pilot sphere. This is termed as “Swept Back Edge Probe” because the edges are swept back to the direction of flow as in the case of aeroplane wings. The relative merits and demerits of these instruments are compared with other velocity measuring instruments.
