During laminar fluid flow, momentum transfer occurs primarily as a result of the_________________?
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Answer: C. Velocity gradient
Explanation
Laminar flow features smooth parallel fluid layers sliding past one another without chaotic mixing. Momentum transfers across these adjacent layers purely through molecular interactions driven by velocity differences. The spatial change in velocity provides the driving force for viscous momentum transport phenomena. Viscosity quantifies a fluid internal friction that resists sliding motion between adjacent stream layers. Newtonian fluids show shear stress directly proportional to the local transverse velocity gradient. Laminar regimes occur predominantly at low Reynolds numbers where viscous forces dominate inertia.
Lubrication films in journal bearings operate under laminar flow conditions relying on fluid viscosity. Blood flow through small capillaries exhibits laminar characteristics governed by velocity gradients. Process engineering calculations for viscous polymer solutions depend heavily on laminar momentum transfer. Option A names viscosity as the property, but the mechanism is driven by the velocity gradient. Option B refers to fluid density which dictates inertial rather than molecular viscous momentum transfer. Option D is incorrect because velocity gradient successfully explains the laminar momentum transfer mechanism.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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