A BEM formulation for evaluating conductive heat transfer rates in particulate systems

NÉSTOR JAVIER MARIANI; SERGIO PATRICIO BRESSA; GERMÁN DÉLFOR MAZZA; OSVALDO MIGUEL MARTÍNEZ; GUILLERMO FERNANDO BARRETO

Numerical Heat Transfer. Part B: Fundamentals

Taylor and Francis Inc

Lugar: Londres, Inglaterra; Año: 1997 vol. 31 p. 459 - 476

1040-7790

A formulation based on the Boundary Element Method (BEM) to solve the conductive heat transfer problem between a particle and an adjacent heat exchange surface or between two particles is presented. This simple geometrical configuration corresponds to a unit cell expected to represent the thermal behaviour near the walls in a fixed or fluidized bed of particles or in the bulk of the bed, from which conductive heat transfer coefficients or effective thermal conductivities can be assessed. It is discussed how the formulation can be employed to evaluate some important phenomena such as chemical reaction, radiative heat transfer or transient effects coupled to heat conduction in the solid particles, without simplifying assumptions such as parallel flux lines. The BEM is formulated by employing a variable number of nodes defined by the same local quadrature points on which the integral coefficients of the influence matrix are evaluated. It is shown that this is a very efficient choice as compared to standard BEM formulation with constant or linear elements.