Large eddy simulation investigation of Reynolds number effects on rheological behavior of Ostwald de Waele fluids

A fully developed turbulent pipe flow of non-Newtonian fluids was investigated numerically using the large eddy simulation (LES) method. The rheological and hydrodynamic behaviour of the pow-er-law fluids was a primary focus for flow behaviour indexes of 0.75, 1, and 1.4 and at simulation Reynolds numbers of 4,000; 8,000 and 12,000. The calculations utilised a finite difference method with a numerical resolution of 653 grid points in the r, theta and z dimensions, respectively. They were sec-ond-order accurate in space and time. According to the results, the shear rate profiles throughout the pipe radius for the pseudoplastic and dilatant fluids noticeably decreased and improved with a higher flow index. Additionally, the elevated flow index caused a notable rise in the fluid viscosity close to the wall, which raised the friction factor.