关键词: 倾斜孔洞流/
休止角/
库仑内摩擦角/
Beverloo公式
English Abstract
Inclined glass-sand flow and the angle of repose
Zhang Yu1,2,Wei Yan-Fang2,3,4,
Peng Zheng5,
Jiang Yi-Min5,
Duan Wen-Shan1,
Hou Mei-Ying2
1.College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China;
2.Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condense Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
3.College of Physical Science and Technology, Yulin Normal University, Yulin 537000, China;
4.Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China;
5.School of Physical and Technology, Central South University, Changsha 410083, China
Fund Project:Project supported by the Special Fund for Earthquake Research of China (Grant No. 201208011), the National Natural Science Foundation of China (Grant Nos. 11274354, 11047003), and the Strategic Priority Research Program-SJ-10 of the Chinese Academy of Sciences (Grant No. XDA04020200).Received Date:25 November 2015
Accepted Date:22 December 2015
Published Online:05 April 2016
Abstract:Systematic experimental study on inclined orifice flow and the measurement of the angle of repose are carried out in this work. The inclined orifice flow is formed by glass beads in an inclined channel. The flow is discharged near the bottom of the channel under gravity. The flow rates are measured at various inclination angles of the channel and opening sizes of the orifice. We then record the inclination angle when the rate becomes zero. We compare this zero-rate inclination angle with the repose angle of glass-beads, and the internal friction angle is determined by the yield stress obtained from a direct shear experiment. It is interesting to find that the experimental values at these three measured critical angles are equal within the experimental errors: 1) the supplementary angle of the extrapolating inclined angle at which the flow rate becomes zero and the inclined hole of diameter approaches infinitely large value (i. e. D), s= 180-c, where c is the critical angle for the inclined hole of diameter D and cc(D); 2) the repose angle r of a cone-shaped pile, which is formed when particles fall from the top point of the heap onto a smooth bottom plate; and 3) the internal friction angle that is measured by direct shear experiment. This result intends to support that the solid-liquid transitions occurring in the inclined orifice flow and free surface of granular heap, and the Coulomb yield occurring in the bulk of the granular solid all originate from the same critical property. Owing to the fact that the internal stresses and strains of samples in the three cases all have complicated and nonuniform distributions so that they cannot be analyzed quantitatively at present, Only some qualitative discussion on this issue is given in this paper.
Keywords: inclined orifice flow/
repose angle/
internal friction angle/
Beverloo formula
