🔍 Key Concepts

• Diesel engine combustion process and how fuel burns inside the cylinder • Role of air motion (swirl/squish/turbulence) in mixing fuel and air • Effect of turbulence on combustion efficiency, pressure, and smoke

💭 Think About

• Think about what needs to happen inside the cylinder right after fuel is injected for efficient burning • Ask yourself: does turbulence make pressure higher, lower, or mainly affect how well things are mixed? • Consider what would happen if there were very little air movement when the fuel is sprayed into the hot compressed air

✅ Before You Answer

• Identify which choice is directly related to fuel–air mixing rather than injection timing or pressure settings • Check whether combustion pressure would realistically be increased or decreased by better mixing • Eliminate any options that deal with injection system characteristics instead of what happens inside the cylinder after injection