🔍 Key Concepts

• Look closely at where the scavenge air enters the cylinder and where the exhaust gases leave (ports in the liner vs. valves in the head). • Review the basic definitions of loop, cross-flow, return-flow, and uniflow scavenging in two‑stroke diesels. • Note the direction of gas flow through the cylinder: does it reverse, swirl in a loop, cross sideways, or move mainly in one straight direction from one end of the cylinder to the other?

💭 Think About

• From the illustration, trace the fresh air path: does it come in through ports around the lower liner, the head, or both? • Look at the exhaust side: are exhaust valves in the cylinder head, or are there separate exhaust ports in the liner opposite the inlet? • Based on that layout, which scavenging system matches a design with ports at one end of the cylinder and valves/ports at the other end, and what does that imply about the main direction of flow?

✅ Before You Answer

• Verify whether the scavenge air ports are only in the lower part of the cylinder liner. • Verify whether the exhaust outlet is only through poppet valves in the cylinder head rather than ports in the liner. • Match that gas‑flow pattern to the formal definition of loop, return-flow, uniflow, or cross-flow scavenging before choosing your answer.