Transition to Turbulence in the Presence of Finite Size Particles

• We study the transition from laminar to turbulent flow in a channel seeded with finite-size neutrally buoyant particles. A fixed ratio of 10 between the channel height and the particle diameter is considered. The flow is examined in the range of Reynolds numbers 500 ≤ Re ≤; 5000 and the particle volume fractions 0.001 ≤ Φ ≤; 0.3. We report a non-monotonic behavior of the threshold value of the Reynolds number above which the flow becomes turbulent, in agreement with previous experimental studies. The mean square velocity fluctuations and Reynolds shear stress of the fluid phase are reduced by increasing the particle volume fraction at a fixed Re=1500, while the mean square velocities of the solid phase are enhanced monotonically suggesting a transition from fluid to particle dominated dynamics at high volume fraction.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering (hsv//eng)

Keyword

finite-size particles

inertial suspensions

Transition

Buoyancy

Reynolds number

Shear flow

Shear stress

Volume fraction

High volume fraction

Mean square velocity

Particle volume fractions

Reynolds shear stress

Transition from laminar to turbulent flows

Transition to turbulence

Suspensions (fluids)

Publication and Content Type

ref (subject category)

kon (subject category)