The flow of mud under a constant axial pressure gradient in eccentric annuli was studied extensively in this paper. Assumed that the inner wall was rotating at a constant angular velocity, then the constitutive equati...The flow of mud under a constant axial pressure gradient in eccentric annuli was studied extensively in this paper. Assumed that the inner wall was rotating at a constant angular velocity, then the constitutive equation of power law fluid and the equation of motion were given. The expressions of apparent viscosity, velocity, flow rate and pressure loss were obtained. In Some numerical results were given by alternation-substitution method. The conclusions are that the viscosity difference between wide and narrow clearance is reduced with increasing the rotation of inner cylinder and/or decreasing the eccentric distance. The flow rate will be increased with increasing the rotation of inner cylinder and eccentric distance, etc.. The pressure loss in eccentric flow is quite large than in concentric axial flow. The results are useful for calculating hydraulic parameters in drilling engineering.展开更多
文摘The flow of mud under a constant axial pressure gradient in eccentric annuli was studied extensively in this paper. Assumed that the inner wall was rotating at a constant angular velocity, then the constitutive equation of power law fluid and the equation of motion were given. The expressions of apparent viscosity, velocity, flow rate and pressure loss were obtained. In Some numerical results were given by alternation-substitution method. The conclusions are that the viscosity difference between wide and narrow clearance is reduced with increasing the rotation of inner cylinder and/or decreasing the eccentric distance. The flow rate will be increased with increasing the rotation of inner cylinder and eccentric distance, etc.. The pressure loss in eccentric flow is quite large than in concentric axial flow. The results are useful for calculating hydraulic parameters in drilling engineering.
