Particle pair statistics of inertial particles at small separation using stereoscopic particle tracking

Particle pair statistics of inertial particles having average Stokes numbers 2.1 and 14 are measured in isotropic turbulence at a Reynolds number Re? = 240. The radial distribution function (RDF) mean relative approach velocity obtained small separation distances using 2-frame stereoscopic particle tracking velocimetry (stereo-PTV). At distance, the RDF varies by an order magnitude range investigated. However, is found to have weak dependence on number. results shown high accuracy when compared analogous mono-PTV datasets, can be used provide more reliable estimate inter-particle collision rate. main limitation measurement observed less than laser sheet thickness, where technique tended underestimate velocity.