Question:
The dimensionless number defined by the ratio of inertial force to viscous force is called
The dimensionless number defined by the ratio of inertial force to viscous force is called
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The Reynolds number is a key dimensionless number used to predict the flow regime in fluid dynamics, helping to determine whether the flow will be laminar or turbulent.
Updated On: Dec 26, 2025
- Mach number
- Froude number
- Weber number
- Reynolds number
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The Correct Option is D
Solution and Explanation
The dimensionless number that represents the ratio of inertial forces to viscous forces is known as the Reynolds number. It is used in fluid mechanics to predict flow patterns in different fluid flow situations. The formula for the Reynolds number is given by:
\[
Re = \frac{\rho v L}{\mu},
\]
where:
- \( \rho \) is the fluid density,
- \( v \) is the velocity of the fluid,
- \( L \) is a characteristic length,
- \( \mu \) is the dynamic viscosity.
The Reynolds number helps determine whether the flow will be laminar or turbulent:
- Low Reynolds numbers (\( Re<2000 \)) indicate laminar flow,
- High Reynolds numbers (\( Re>4000 \)) indicate turbulent flow.
Thus, the correct answer is (D) Reynolds number. Final Answer: (D) Reynolds number
- \( \rho \) is the fluid density,
- \( v \) is the velocity of the fluid,
- \( L \) is a characteristic length,
- \( \mu \) is the dynamic viscosity.
The Reynolds number helps determine whether the flow will be laminar or turbulent:
- Low Reynolds numbers (\( Re<2000 \)) indicate laminar flow,
- High Reynolds numbers (\( Re>4000 \)) indicate turbulent flow.
Thus, the correct answer is (D) Reynolds number. Final Answer: (D) Reynolds number
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