variavel0=<b>Yuri Dumaresq Sobral</b> - yurisobral@bol.com.br UnB
<b>Francisco Ricardo da Cunha</b> - frcunha@unb.br UnB
<b>Abstract.</b> In this work the effect of various physical parameters on the stability of fluidized beds is evaluated by the means of a normal mode analysis. The effect of a inertial drag on the fluid particle interaction force is explored. The present study is carried out for liquid-solid and gas-solid fluidized beds. It is verified that the behaviour of fluidized beds varies according to the type of fluidization, indicating that the specific mass ratio plays a key role in the stability of these systems. Diferent models are proposed for the particle pressure and the particle viscosity of the disperse phase.
<b>Keywords.</b> Fluidized beds, Instability, Inertial drag, Particle pressure, Particle viscosity.