Nuclear mgnetic resonance study of granular flows. Final report
We have demonstrated the efficacy of NMRI to granular flow studies of objects that yield NMR signals (seeds, pharmaceutical pills) in confined spaces (rotating cylinders, shaking boxes). Excellent results for velocity and concentration of flowing and colliding particles have been obtained non-invasively. We studied flows in geometries that are otherwise impossible to study because of the optical opacity of the materials. In addition, we obtained data for diffusion and collisional losses which must be related to granular temperature. We also measured the global collisional and frictional energy loss for a rotating cylinder containing granular material and compared it to that obtained from the NMRI velocity and acceleration data. We used the same NMR technique to study the interplay between radial and axial segregation of heterogeneous particles in a partially filled rotating cylinder. We also measured flow and diffusion of vibrating particles in the NMRI apparatus to ascertain that such experiments are, indeed, possible. Some theoretical studies were initiated to explain some of the velocity profiles and free surface shapes of rotating drum flow. A direct numerical simulation of the drum flow successfully predicted a number of features, including velocity, concentration, and dissipation profiles in rotating cylinders.
- Research Organization:
- Lovelace Insts., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC22-90PC90184
- OSTI ID:
- 73928
- Report Number(s):
- DOE/PC/90184-T18; ON: DE95015601
- Resource Relation:
- Other Information: PBD: Mar 1995
- Country of Publication:
- United States
- Language:
- English
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