Effects of polymer additives on turbophoresis in a turbulent channel flow

• Turbophoresis is the migration of inertial particles towards the wall in a wall-bounded flow induced by turbulence. In this work, we analyze the effects of drag reducing polymer additives on turbophoresis in a turbulent channel flow. The numerical data set is obtained from a direct numerical simulation (DNS) of a turbulent channel flow of a viscoelastic fluid and laden with particles of different inertia. The results indicate that polymer additives decrease the turbophoretic drift. We establish that turbophoresis is reduced because of the smaller wall-normal variation of wall-normal fluid velocity fluctuations that occurs in all drag reducing flows. Hence a reduction of turbophoresis should be a common feature of all drag reducing flows such s fiber, bubble suspensions and MHD.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Nyckelord

Additives

Channel flow

Drag reduction

Polymers

Turbulence

Wall flow

Bubble suspension

Drag-reducing polymers

Inertial particles

Normal variations

Normal-fluid velocity

Turbulent channel flows

Vis-coelastic fluids

Wall bounded flows

Magnetohydrodynamics

Publikations- och innehållstyp

ref (ämneskategori)

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