Identify the parameter that is NOT dimensionless for flowing liquids Which of the following is not a dimensionless parameter used to characterize fluid flow?

Introduction / Context:
Fluid dynamicists routinely use dimensionless numbers to compare flows across scales and media. Recognizing which quantities are dimensionless prevents errors when applying similarity laws and correlating experimental data.

Given Data / Assumptions:

• Standard SI or consistent unit systems.
• Typical external or internal flows without phase change.

Concept / Approach:

Reynolds number, Weber number, pressure coefficient, and Darcy–Weisbach friction factor are all non-dimensional by construction. Kinematic viscosity ν has units of area per time (L^2/T) and is not dimensionless.

Step-by-Step Solution:

Verification / Alternative check:

Dimensional analysis (Buckingham π theorem) confirms that Re, We, etc., arise as π-groups; ν is a base property, not a π-group.

Why Other Options Are Wrong:

They are standard dimensionless measures widely tabulated in fluid handbooks.

Common Pitfalls:

Confusing ν with the reciprocal of Reynolds number; they are related but not interchangeable.

Final Answer:

Kinematic viscosity