For pressure drop computations, what is the equivalent diameter of a square channel with side length ‘x’____________________?
Show answer Hide answer
Answer: C. x
Explanation
The hydraulic equivalent diameter for a symmetrical square channel of side length x evaluates simply to x. Calculating four times the cross-sectional area divided by the wetted perimeter yields x squared over x. This geometric simplification allows square ducts to be analyzed using standard pipe friction formulas. Equivalent diameter converts non-circular cross-sections into an effective circular size for flow calculations. A square channel has equal width and height, making area and perimeter calculations straightforward. This parameter ensures that friction factor correlations remain valid for rectangular ventilation ducts.
HVAC engineers use equivalent diameters to size square air conditioning ducts and estimate pressure losses. Accurate sizing prevents inefficient fan operation and ensures proper airflow delivery to rooms. Simplifying channel geometry saves computational time in complex building service designs. Option A multiplies the side length by four, which erroneously treats the perimeter as the diameter. Option B doubles the side length, yielding an incorrect hydraulic radius conversion factor. Option D introduces a square root that has no mathematical basis in square duct geometry.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Which fluid property prevents mercury from wetting glass surfaces__________________?
Show answer Hide answer
Answer: A. Surface tension
High surface tension generates strong inward cohesive forces among mercury liquid molecules. These powerful cohesive forces dominate over adhesive forces between mercury and solid glass. The resulting interfacial energy...
Q2. Liquid flowing at a steady rate through a tapered pipe represents _______________ flow.
Show answer Hide answer
Answer: B. Steady non uniform
Flow velocity changes along the length of a tapered pipe due to varying cross-sectional areas, making it non-uniform. Because the mass flow rate remains constant over time at any given location, the flow is classified as...
Q3. Gas flowing through a pipe toward regions of lower pressure experiences a reduction in its__________________?
Show answer Hide answer
Answer: B. Specific volume
Gases expand significantly when flowing toward regions of lower ambient static pressure. Expansion increases the volume occupied by a given mass of gas. Specific volume is defined as volume per unit mass, which increases...
Q4. What equation name is given to the friction factor relation f-0.5 = 4 loge (NRe/√f)-0.4 _____________?
Show answer Hide answer
Answer: A. Nikuradse
The Nikuradse friction factor relation for smooth and rough pipes uses the constant 0.4 in its logarithmic formula. Nikuradse conducted pioneering experiments on artificially roughened pipes to map turbulent friction beh...
Q5. What general expression links pump speed N, head H, power P, and discharge Q for centrifugal pumps_________________?
Show answer Hide answer
Answer: A. Q∝N : H∝N2 : P∝N3
Centrifugal pump affinity laws state that discharge is proportional to speed, head to squared speed, and power to cubed speed. Dimensional analysis of impeller geometry confirms these exact scaling relationships for geom...
Q6. How does the friction factor behave for turbulent flow inside a hydraulically smooth pipe______________?
Show answer Hide answer
Answer: A. Depends only on Reynolds number
In hydraulically smooth pipes, surface roughness projections are entirely submerged within the viscous sublayer. Fluid friction depends exclusively on viscous shear interactions near the pipe wall. The Reynolds number co...