assessment of piv technique on determination of turbulence scales

the proper and quantitative recognition of the scale of turbulence in regard to issues such as sediment transport is of major importance. different experimental techniques can be used to determining the scale of turbulence, but the accuracy of these techniques is open to question. in this paper, after a review of the taylor method, the restrictions and advantages of velocity measurement techniques such as hot wire anemometry (hwa), laser doppler velocimetry (ldv) and particle image velocimetry (piv) are described. correlation coefficients were applied to determine the scale of turbulence using these techniques. the results showed that the main restrictions of the hwa technique were its intrusiveness and the sensitivity of the sensor. the ldv technique was restricted to measuring correlation coefficients in small distances and for just one velocity component. the results showed that the piv technique has restrictions in its framing rate, saving image, image resolution and laser pulsing frequencies. however, considering the large spatial domain of piv and its non-intrusive measurements and especially the continuous development of its capabilities, piv is an appropriate technique for determination of the scale of the flow of turbulence.