Statistical analysis of sand grain/bed collision process recorded by high-speed digital camera |
| |
| Authors: | DAWEI WANG YUAN WANG BIN YANG WEI ZHANG† |
| |
| Institution: | Fluid Engineering Department, School of Energy &Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China (E-mail: );
Experimental Flow Control &Biofluid Laboratory, Pohang University of Science and Technology, Pohang 319-1188, Korea |
| |
| Abstract: | A high‐speed digital camera was employed to record the sand grain/bed collision process. With image processing and a statistical method, a series of parameters of the collision process were obtained. The results show that the collision process of a grain with rebounding can be represented by two parameters: the kinetic energy restitution coefficient and the collision angle. Both parameters satisfy a normal distribution, and they are dependent on one another. With an increase of the collision angle, the distribution of the kinetic energy restitution gradually reduces from a broad to a narrow range with low values. The percentage of vertical velocity restitution coefficients greater than 1 can reach 70% or more, which ensures that the settling time of the sand grains in the air increases and that they receive more energy from the air to progress the saltation movement. |
| |
| Keywords: | Grain/bed collision high-speed digital camera image processing saltation statistical analysis |
|
|
