TY - JOUR
TI - Friction factors and internal flow length scales of gas-solid magnetically stabilized beds in axial fields: Scaling and applications to bed-to-surface heat transfer
AU - Hristov Jordan Y
JN - Thermal Science
PY - 2005
VL - 9
IS - 1
SP - 73
EP - 98
PT - Article
AB - Friction factors and internal flow length scales of gas-solid magnetically stabilized beds are discussed. Pressure drop and expansion data of beds stabilized by axial magnetic fields are used. The concept of a variable friction factor of fluid-driven deformable packed bed is discussed. Scaling relationships of the internal flow length scale and the bed overall porosity are developed through three approaches: (1) fluidization approach concerning a length scale proportional to the particle size, (2) packed bed approach based on a hydraulic diameters as a length scale, and (3) porous media approach based on the Forchheimer equation. The main result is that the bed length scale ~e", irrespective of the model used, where n is the exponent of the Richardson-Zaki scaling law. These scaling estimates are used to explain the magnetic field effects on bed-to-surface heat transfer coefficients.