Oil (SG = 0.9, Dynamic viscosity = 1 Poise) is flowing with a mean velocity of 1 m/s between two fixed parallel plates which are 1 cm apart. What will be shear stress at the surface of the plate? 

Concept:

Pressure difference b/w two points in Laminar flow b/w two fixed parallel plate

Maximum shear stress of Laminar flow b/w two fixed parallel plate

Calculation:

Given:

Specific Gravity = 0.9 ⇒ Density (ρ) = 900 kg/m³

μ = 1 poise ⇒ 0.1 Ns/m²

v = 1 m/s, t = 1 cm ⇒ 0.01 m

The pressure difference is:

Maximum shear stress is:

τ_max = 60 N/m²