Flow of non-newtonian fluids in a pipe

来自 dx.doi.org

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140

作者：

FT Pinho，JH Whitelaw

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摘要：

Measurements of mean axial velocity and of the three normal stresses have been obtained in fully developed pipe-flow with four concentrations of a polymer (sodium carboxymethyl cellulose) in aqueous solution and with water and viscous Newtonian fluids encompassing a range of Reynolds numbers from 240 to 111,000. The results quantify the delay in transition from laminar to turbulent flow caused by shear-thinning, the suppression of turbulent fluctuations particularly in the radial and tangential components of normal stress, and the drag reduction at the higher Reynolds numbers. They also confirm that the maximum drag reduction asymptote is appropriate to these shear-thinning solutions.

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关键词：

Experimental/ drag reduction fluctuations laminar to turbulent transitions laser velocimetry non-Newtonian flow pipe flow polymer solutions shear turbulence velocity measurement/ nonNewtonian flow pipe flow laser velocimetry mean axial velocity normal stresses polymer sodium carboxymethyl cellulose aqueous solution water viscous Newtonian fluids Reynolds numbers transition laminar to turbulent flow shear-thinning turbulent fluctuations drag reduction/ A4780 Measurement instrumentation and techniques for fluid dynamics A4760 Flows in ducts, channels, and conduits A0630G Velocity, acceleration and rotation measurement A4750 Non-Newtonian dynamics A4715F Stability of laminar flows A4725F Boundary layer and shear turbulence