Turbulence of viscoelastic fluid-from practical examples to turbulent coherent structure

Abstract

It is known that when a surfactant or a water-soluble polymer is added to water, the fluid becomes viscoelastic and the turbulent frictional drag due is significantly reduced by the Toms effect. In this report, I will introduce examples of practical research and basic study on the Toms effect. In the practical research aiming at energy saving, the case of the building air conditioning system using the surfactant and the case of the ship using the ship hull paint were introduced. In a basic study simulating the use of ship hull paint containing water soluble polymer, it was clarified that the polymer supplied from the wall surface strongly affects the coherent structure of wall turbulence, suppresses Reynolds shear stress, and reduces wall friction resistance.