Experimental Investigation of Effective Wall Friction Coefficient for Steady Dry Dense Granular Flows down a Rough Incline
| Autor: | Zhan-Wei Xu, 許展維 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 This work investigates the effective wall friction coefficient μw for steady dry granular flows of mono-sized Polyoxymethylene spheres down an inclined rough chute through systematic experiments. Direct force measurements via normal and shear load cells were conducted on chute base and at chute lateral wall so that bulk basal and lateral friction coefficients were obtained simultaneously. In addition, particle tracking velocimetry and sphere angular velocity measurement were achieved with high-speed imaging technique. Through averaging, we obtained depth profiles for bulk velocity νx, angular speed ω, and granular temperature Tx from which different dimensionless parameters were evaluated to describe μw. We also conducted sliding table experiment to measure pure sliding friction coefficient between the sphere and the chute side wall, μpw, so that a normalized µw/µpw was examined with respect to inertial number, I, scaled granular temperature, √Tx/νx, and rotation index, Ω = Rω/νx. The measured correlations were compared to those reported from discrete element simulation literature and we explains the similarities and discrepancies. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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