A solution procedure for three-dimensional free convective flow in peaked bulks of grain

Abstract

This paper presents a methodology to solve numerically the equations that govern the behaviour of free convective processes occurring in peaked bulks of grain. The momentum transfer equation based on Darcy's law is expressed in terms of a vector potential that also ensures conservation of mass. It is assumed that the walls and roof of the bunker are isothermal, whilst the floor is adiabatic. The governing equations and boundary conditions in the physical domain are transformed into a computational domain by means of an algebraic method of transformation applicable to any geometry. The governing equations in the computational domain discretised on uniform grids are solved using an alternating direction implicit method. During each real time step the steady-state solutions of the vector potential components are evaluated by means of a false transient method. Results in graphical form are presented for the temperature, vector potential components, grain moisture content, dry matter loss and pesticide decay, at selected cross-sections of a peaked bulk of grain.