🔍 Key Concepts

• four-stroke diesel cycle and what happens on each stroke • difference between boosting intake pressure and internal air motion in the cylinder • terms used for removal of exhaust gases vs. mixing of air and fuel

💭 Think About

• On which stroke is air–fuel mixing most critical in a four-stroke diesel, and what kind of motion inside the cylinder helps that mixing? • Which choice describes a pressure increase before the air enters the cylinder, and which describe flow patterns inside the cylinder? • Which term is normally used for clearing out exhaust gases rather than mixing fuel and air?

✅ Before You Answer

• Identify which options refer to pressure charging from outside the cylinder versus movement of gases inside the cylinder • Recall that in a four-stroke diesel, scavenging has a specific purpose related to exhaust gases, not primarily mixing • Ask: which term in the options is most directly tied to chaotic internal air motion that improves mixing?