WIND TUNNEL EXPERIMENT OF SAND VELOCITY IN NATURE AEOLIAN SAND TRANSPORT USING PARTICLE IMAGE VELOCIMETRY
Sand velocity in aeolian sand transport is measured using the PIV system(Particle Imaging Velocimetry) in a wind tunnel.The velocity probability distribution of ascending and descending particles,as well the influences of sand ripple on the sand particle motion are analyzed.The results show that velocity distributions of take-off particles and particles during sand movement accord with logarithm normal distribution.The mean incident velocity of sand particles is 1.005-1.4 times higher than take-off ones with different wind speed.It is found that sand ripples play an important role on the sand particles motion,which is a key factor that can not be neglected.