Uniflow (uniflow-scavenged) steam engine: identify the correct flow path of steam through the cylinder. Definition focus: where admission occurs and where exhaust leaves in a unidirectional flow pattern for better thermal efficiency. Choose the correct statement about steam entry and exhaust in a uniflow engine.
Mechanical Engineering
Steam Boilers and Engines
Difficulty: Easy
Choose an option
-
ASteam enters and exhausts through the same port
-
BSteam enters at one end (cylinder head) and exhausts at the centre through ports
-
CSteam enters at the centre and exhausts at the other end
-
DNone of the above
Answer
Correct Answer: Steam enters at one end (cylinder head) and exhausts at the centre through ports
Explanation
ConceptIn a uniflow engine, steam flows in one direction. Admission occurs at the cylinder head (end), while exhaust takes place through ports located near the middle of the cylinder, uncovered by the piston near the end of the power stroke.
Why this improves performance
- Reduces thermal cycling of the cylinder ends (lower condensation losses).
- Improves scavenging because the flow is predominantly one-way.
Answer noteOption B captures the essential feature: admission at the end and exhaust near the centre.