USCG Exam PracticeDiesel engine principles (motor propulsion)
A diesel engine ignites its fuel charge without a spark plug because the fuel is injected into air that has been raised to approximately what temperature by compression?
- A. 400 degrees F
- B. 600 degrees F
- ✓ 1000 degrees FCorrect
- D. 1500 degrees F
Why C is correct
Compressing air alone to roughly 300-500 psi raises its temperature to about 1000 degrees F, which is well above the auto-ignition point of diesel fuel, making a spark plug unnecessary. (DOE-HDBK-1018 Vol.1 §1-1)
Cited:DOE-HDBK-1018 Vol.1 §1-1