A Couette shear cell: the lower plate is fixed, the upper plate is dragged sideways, and the fluid between them is sheared. Move the sliders to watch τ = μ × (du/dy) respond — the arrows are the fluid's own speed at each height.
Shear rate du/dy = U ÷ h
500.0 s-1
1.00 m/s across a 2.0 mm gap
Shear stress τ = μ × (du/dy)
0.5000 Pa
0.001 Pa·s × 500.0 s-1
Viscous force F = τ × A
0.1250 N
over A = 0.25 m²
Power dissipated P = F × U
0.1250 W
heat put into the fluid every second
Kinematic viscosity ν = μ ÷ ρ
1.000e-6 m²/s
1.000 cSt at 1000 kg/m³
Dynamic viscosity μ0.001 Pa·s
Plate speed U1.00 m/s
Gap h2.0 mm
Plate area A0.25 m²
Density is held at 1000 kg/m³ and is used only for ν. The flow is taken as steady and laminar, with no slip at either plate.
Tip: halve the gap and the shear rate doubles, so the stress and the force double with it — at exactly the same plate speed.