Friction Mean Effective Pressure (FMEP)
FMEP = IMEP − BMEP - the 'lost' pressure to friction. Rising FMEP = bearing/ring wear.
FMEP
2.00bar
Mechanical efficiency η_m
0.909 -
Formula, assumptions, and limits
Two-stroke marine diesel typical FMEP 1–2 bar (η_m ≈ 0.90–0.92). Four-stroke medium speed 2–3 bar (η_m ≈ 0.85–0.88). Trending rise in FMEP over months = main / crosshead bearing / ring-pack wear.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Indicated MEP | bar | indicator card | |
| Brake MEP | bar | torsionmeter | |
| Friction MEP | bar | result |