The Force Acted On Inner Cylinder Of Fluid Flowing In Eccentric Annuli With The Inner Cylinder Reciprocating Axially

In the oil pumping process, due to pumping wells deeper reasons, pumping rod is eccentric in oil tube, the sucking fluid flow in the eccentric annuli formed by the oil tube and pumping rod, which induce the force exerted by the sucking fluid on the pumping rod, this force can aggravate the problem of eccentric wear of pumping rod. Therefore, It is significant to study the force acted on the inner cylinder of fluid flowing in eccentric annuli with the inner cylinder reciprocating axially theoretically, with analyzing and preventing eccentric wear the problems and optimizing the operating parameters of the pumping unit.In this paper, based on the basic equations of the unsteady flow of the fluid in the eccentric annuli with the inner cylinder reciprocating axially in bipolar coordinate system, the calculation formulae of the force acted on the inner cylinder of fluid flowing in eccentric annuli with the inner cylinder reciprocating axially in the bipolar coordinate system were established and the relative numerical calculation method of the force was given. Using Basic Visual 6.0, the program "the force acted on the inner cylinder of fluid flowing in eccentric annuli with the inner cylinder reciprocating axially" was programmed. Taking the water for examples, the force acted on the inner cylinder of water flowing in eccentric annuli with the inner cylinder reciprocating axially was numerically calculated, and the effects of annulus eccentricity, the stroke and the stroke frequency of the inner cylinder and the viscosity of water on the forces were analyzed.