چکیده (انگلیسی):

The oscillatory flow of micropolar fluid in an annular region with constriction, provided by variation of the outer tube radius, is investigated. It is assumed that the local constriction varies slowly over the cross-section of the annular region. The nonlinear governing equations of the flow are solved using a perturbation method to determine the flow characteristics. The effect of micropolar fluid parameters on mean flow and pressure variables is presented.