Analysis of Generalized Reynolds Numbers for Different Types of Fluids Flowing in Circular Pipes
Reynolds number is an important parameter for characterizing the flow characteristics of fluids in pipes.Based on the complex rheological model of Carreau-Extended(referred to as Carreau-E)non-Newtonian fluid containing yield stress,time constant and power law index and the force balance equation,the generalized Reynolds number expression of laminar flow in a fully developed Carreau-E fluid in a circular pipe was derived.It was further extended to Carreau,Herschel-Bulkley,Power-law and Bingham,four common non-Newtonian fluids and Newtonian fluids.Through a comparative study,it is found that the experi-mental values of Darcy friction factors for different types of fluids flowing through pipes are in good agreement with the predicted values,and the relative errors are basically within±10%.This study can provide a basis for determining the flow patterns of pipe flows for different non-Newtonian or Newtonian fluids.
万方数据
维普
