This is a photo of two laser
Doppler velocimetry probe systems (instruments in our
Comprehensive LDV program) that are spaced 5mm laterally in the
photo making simultaneous measurements in a turbulent boundary
layer flow. The probe volume centered in the photo is making
simultaneous measurements of velocity, acceleration, and
resolved particle crossing position within the beam crossing
intersection. The other probe is making velocity and
acceleration measurements. Data acquisition is synchronized to
allow for time-delay correlation estimates between the
measurements from each probe. We are interested in gathering
information on length scales based upon the coherency function
between the sets of data from one probe to the next. Such
measurements will be used to develop models that explain the
physics of boundary layers subjected to high freestream
turbulence effects. Credit to Todd Lowe, Qing Tian, and Dr.
Roger Simpson. (February 2006)
