In a two-stroke/cycle diesel engine, the...

Question 1 of 270705eccefa2bacbc34ba4d47ab1

In a two-stroke/cycle diesel engine, the process of scavenging begins as the __________.

Question 1 of 27070

In a two-stroke/cycle diesel engine, the process of scavenging begins as the __________.

🔍 Key Concepts

• Two-stroke diesel scavenging: what scavenging is and why it happens • Piston position vs. port openings: how intake/scavenge and exhaust ports are uncovered and covered • Difference between TDC (Top Dead Center) and BDC (Bottom Dead Center) in the two-stroke cycle

💭 Think About

• Think about when fresh air (or air-fuel mixture) must enter the cylinder to push out exhaust gases in a two-stroke engine. Is this closer to the top of the stroke or the bottom? • In a uniflow or loop-scavenged two-stroke diesel, when are the ports actually open? Relate that to piston movement near BDC or TDC. • Visualize one full crankshaft revolution in a two-stroke: at what part of the stroke are both exhaust and scavenge ports open together so scavenging can occur?

✅ Before You Answer

• Make sure you know that in a two-stroke diesel, one power stroke happens every revolution, and port opening is controlled by piston position, not valves (for typical marine designs). • Verify at which point in the stroke the scavenge ports and exhaust ports are open at the same time – this is when scavenging actually takes place. • Check whether scavenging can occur when the piston is very close to TDC, or whether it must be near BDC where the ports are exposed.