Over extended periods of service and aging, what physical change occurs inside fluid-carrying pipelines regarding the__________________?
Show answer Hide answer
Answer: D. Absolute roughness increases linearly with time
Explanation
Prolonged exposure to corrosive fluids physically degrades the smooth interior walls of industrial metal pipelines. Chemical scaling and mineral deposits physically accumulate on pipe inner surfaces over long operational lifespans. Surface degradation progressively increases the absolute roughness parameter as microscopic pits and bumps multiply. Absolute roughness represents the average height of surface irregularities inside a closed conduit. Pipe aging directly impacts pumping energy requirements by elevating fluid frictional resistance over time. Internal pipe corrosion can be mitigated through protective coatings or appropriate chemical inhibitor treatments.
Industrial plant operators monitor pipe roughness to schedule preventative maintenance and chemical cleaning cycles. Increased roughness raises operational energy costs across long distance water distribution and oil pipelines. Accurate friction models require accounting for roughness growth to predict pressure losses accurately. Option a is incorrect because physical wear and deposits generally roughen rather than smooth pipes. Option b implies a linear friction factor increase, but friction depends non-linearly on regime transitions. Option c wrongly claims roughness decreases, which contradicts the physical reality of corrosion accumulation.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Each term in the Bernoulli equation expressed as (p/ρ) + (g/gc). Z + (v2/2gc) = constant corresponds to the total energy per unit ________________?
Show answer Hide answer
Answer: A. Mass
Dividing total energy terms by gravitational conversion factors yields specific energy per mass. Pressure divided by density plus elevation and kinetic terms equals energy per unit mass. This specific energy form is stan...
Q2. Euler’s equation of motion states that at any given point_________________?
Show answer Hide answer
Answer: B. Force per unit mass equals acceleration
Euler equation of motion states that net pressure and body forces per unit mass equal fluid acceleration. Applying Newton second law to an inviscid fluid element along a streamline yields this fundamental relationship. F...
Q3. For spherical particles moving through a stationary fluid within the Stokes' law regime, the drag coefficient equals_________________?
Show answer Hide answer
Answer: A. 24/NRe,P
Stokes law derivation involves balancing viscous drag forces and gravitational forces on a sphere. The dimensionless particle Reynolds number is defined using particle diameter and fluid velocity parameters. Mathematical...
Q4. The friction factor relation f = 16/NRe holds true for__________________?
Show answer Hide answer
Answer: D. None of these
The exact mathematical expression sixteen divided by the Reynolds number defines circular pipe laminar flow friction. Open channel flow geometries utilize different hydraulic radii and wetted perimeters than closed circu...
Q5. The Fanning friction factor for laminar flow inside a circular pipe is equal to____________________?
Show answer Hide answer
Answer: C. Both A. & B.
In laminar pipe flow, the Fanning friction factor equals sixteen divided by the Reynolds number. This mathematical derivation proves the friction factor depends exclusively on flow velocity and fluid properties. Pipe wal...
Q6. What is the mathematical relationship defining the Fanning friction factor, where fB denotes the Blasius friction factor ?
Show answer Hide answer
Answer: A. fB/4
The Darcy Weisbach friction factor incorporates a factor of four compared to the Fanning friction definition. Dividing the Blasius or Darcy friction factor value by four correctly yields the corresponding Fanning frictio...