If velocity is zero across half of the cross-sectional area and constant over the other half, what is the momentum correction factor_______________?
Show answer Hide answer
Answer: C. 2
Explanation
Integrating velocity profile variations across the cross-sectional area yields a momentum correction factor of 2. Momentum correction accounts for non-uniform velocity distribution across pipe or channel sections. Applying the specific step velocity distribution given in the problem results in a factor of 2. Momentum correction coefficients, often designated as beta, adjust momentum flux calculations. Real fluid velocities vary from zero at stationary walls to maximum values at flow centerlines. Integration methods combine area, velocity, and density variables to determine precise correction factors.
Civil engineers use momentum correction factors when analyzing hydraulic jump forces in open channels. Accurate momentum calculations prevent structural failure in pipe bends and fittings subjected to high flow. Understanding velocity distribution improves the precision of fluid mechanics design calculations. A momentum correction factor of 1 assumes completely uniform velocity across the entire cross-section. Stating 4/3 incorrectly calculates the momentum coefficient for this specific velocity step profile. A factor of 4 overestimates the integrated momentum correction for the described area distribution.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. For a hydrodynamically smooth boundary, what describes the friction coefficient during turbulent flow_______________?
Show answer Hide answer
Answer: B. dependent only on Reynolds number
In a hydrodynamically smooth pipe boundary, friction coefficient depends solely on the Reynolds number. Surface roughness elements are completely submerged within the laminar sublayer during smooth turbulent flow. Relati...
Q2. The center of buoyancy is located such that it always_________________?
Show answer Hide answer
Answer: B. coincides with the centroid of the volume of fluid displaced
Archimedes principle dictates that the center of buoyancy matches the geometric centroid of displaced fluid. Buoyant force acts vertically upward through this volumetric centroid of the submerged object portion. Shape an...
Q3. In circular pipes under laminar flow, how is Darcy’s friction factor f expressed_________________?
Show answer Hide answer
Answer: C. 64/ Re
Darcy’s friction factor for circular pipes under laminar flow is expressed as 64 divided by Reynolds number. Theoretical integration of the Hagen-Poiseuille velocity profile yields this exact mathematical relationship. M...
Q4. If the hydraulic grade line elevation at a three-pipe junction sits above reservoirs B and C but below reservoir A, in which direction will the flow proceed___________________?
Show answer Hide answer
Answer: C. from reservoir C to reservoirs A and B
When the junction hydraulic grade line sits below reservoir A but above B and C, fluid flows outward from reservoir C into both A and B under specific head conditions.
Q5. If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is__________________?
Show answer Hide answer
Answer: C. 9/4
Calculating the kinetic energy correction factor using the specified velocity profile yields 9/4. Kinetic energy correction accounts for non-uniform velocity distributions in energy equation analyses. Integrating the cub...
Q6. For laminar flow inside a circular pipe, what is Darcy’s friction factor f________________?
Show answer Hide answer
Answer: C. inversely proportional to Reynolds number and indpendent of pipe wall roughness
In laminar pipe flow, Darcy friction factor depends solely on the Reynolds number calculation. Pipe wall roughness has zero impact on friction losses because fluid layers slide smoothly past one another. Theoretical Hage...