DETERMINATION DE LA VITESSE D'ECOULEMENT D'UN MILIEU GRANULAIRE PAR LA METHODE DE GALERKINE

The difficulties bound to the transport of the granular materials in the industry brought numerous authors to propose some models in order to control the out-flow of these materials. The works of POLDERMAN permit to determine the field of velocity of the out-flow in mass of
the unalterable granular materials from a mathematical model based on hypothesis according to which the angle ψ between the major main axis of the constraint and the half angle θ at the summit of a conical hopper is a linear function of θ with the following form: ψ = C1θ . For a given value of the ray r, he determines the out-flow velocity of the continuity equation by means of the unknown velocity for ψ = 0. Using the approached solution of the continuity equation calculated by the GALERKINE method, we determine the absolute error depending of the unknown velocity. With the given approximation precision the constraint on the unknown velocity is calculated.

Mots clés : 1- matériaux granulaires indéformables- 2 champ de vitesse -3 axe majeur, Keywords: 1 - unalterable granular surroundings - 2 field of speed -3 major axis