Numerical investigation of a non-Newtonian fluid flow through a contraction pipe

Flow characteristics near a sudden contraction for a pipe is analyzed in this study. The study consists of three phases. In the first phase, existing experimental results for water using a Particle Image Velocimetry (PIV) method performed by one of our group members were compared with numerical simulation results. In the second phase, for certain Re values, numerical simulation results for water and polyacrylamide solution, which is an inelastic non-Newtonian fluid, were compared. In the last phase, numerical simulations were performed for polyacrylamide considering smaller Reynolds numbers. The results of first phase studies show that experimental and numerical results agree with each other fairly well; demonstrating that the numerical software we use is correct and dependable. The results of second and third phase studies show that the differences between flow characteristics of Newtonian and non-Newtonian fluids. For the same Re, streamwise and transverse velocity values for non-Newtonian fluid are much smaller than the Newtonian fluid while the vorticity values for non-Newtonian fluid are higher than Newtonian fluid.