At t=0, the lower plate is at a constant velocity ∆v ied force F being

Chapter

ABSTRACT

FIGURE 8.2: Transient velocity profile of a fluid between two parallel plates.

the so-called Reynolds number after the Irish mathematician and physicist Osborne Reynolds (1842-1912). For a flow passing through a straight circular pipe of diameter D, the Reynolds number, which is dimensionless, is defined by

Reynolds number = density×D × flow speed

viscosity .

At t=0, the lower plate is at a constant velocity ∆v ied force F being applied. F ∆v For small t, the layer immediately to the bottom plate is carried along at the velocity of this plate. The layer just above it is moving at a slightly slower velocity, etc. ∆v

ABSTRACT