AIRCRAFT INVESTIGATION
performance calculations for the Lorraine-Dietrich 12Da WWI aero engine
Lorraine 12D on display at the National Museum of Nature and Science in Tokyo, Japan (source Wikipedia)
Lorraine-Dietrich 12Da liquid-cooled 12 -cylinder V-engine 370 [hp](275.9 KW)
introduction : 1917 country : France importance : ****
applications : Bleriot SPAD S.46
normal rating : 370 [hp] (275.9 KW) at 1650 [rpm] at 0 [m] above sea level
no reduction, direct drive, valvetrain : SOHC
fuel system : oil system :
weight engine(s) dry : 420.0 [kg] = 1.52 [kg/KW]
bore : 120.0 [mm] stroke : 180.0 [mm]
valve inlet area : 22.0 [cm^2] one inlet and one exhaust valve in cylinder head
gasspeed at inlet valve : 35.8 [m/s]
throttle : 88 /100 open, mixture :13.0 :1
calculated compression ratio : 5.32 : 1
stroke volume (Vs) : 24.4 [litre]
compression volume (Vc): 5.655 [litre]
total volume (Vt): 30.084 [litre]
engine height : 110 [cm] engine width :107 [cm]
engine length: 1.08 [m]
specific power : 11.3 [kW/litre]
torque : 1597 [Nm]
engine weight/volume : 17.2 : [kg/litre]
average piston speed (Cm): 9.9 [m/s]
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intake pressure at 0 [m] altitude Pi : 0.85 [kg/cm2]
mean engine pressure (M.E.P.) at 0 [m] altitude Pm : 6.54 [kg/cm2]
compression pressure at 0 [m] altitude Pc: 6.86 [kg/cm2]
estimated combustion pressure at 0 [m] Pe : 27.42 [kg/cm2]
exhaust pressure at 0 [m] Pu : 3.34 [kg/cm^2 ]
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compression-start temperature at 0 [m] Tic: 367 [°K] (94 [°C])
compression-end temperature at 0 [m] Tc: 544 [°K] (271 [°C])
average engine wall temperature at 0 [m] : 476 [K] (202 [°C])
caloric combustion temperature at 0 [m] Tec: 2138 [°K] (1865 [°C])
polytroph combustion temperature at 0 [m] Tep : 2172 [°K] (1899 [°C])
estimated combustion temperature at 0 [m] Te (T4): 2131 [°K] (1858 [°C])
polytrope expansion-end temperature at 0 [m] Tup: 1172 [°K] (899 [°C])
exhaust stroke end temperature at 0 [m] Tu: 1106 [°K] (833 [°C])
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emergency/take off rating at 1920 [rpm] at sea level : 402 [hp]
Thermal efficiency Nth : 0.342 [ ]
Mechanical efficiency Nm : 0.766 [ ]
Thermo-dynamic efficiency Ntd : 0.262 [ ]
design hours : 972 [hr] time between overhaul : 19 [hr]
dispersed heat by cooling fluids at 1650.00 [rpm] at 0 [m]: 78.79 [Kcal/minute/litre]
fuel consumption optimum mixture at 1650.00 [rpm] at 0 [m]: 80.37 [kg/hr]
specific fuel consumption thermo-dynamic : 230 [gr/epk] = 308 [gr/kwh]
estimated specific fuel consumption (cruise power) at 0 [m] optimum mixture : 320 [gr/kwh]
estimated sfc (cruise power) at 2525 [m] rich mixture : 330 [gr/kwh]
specific fuel consumption at 0 [m] at 1650 [rpm] with mixture :13.0 :1 : 291 [gr/kwh]
estimated specific oil consumption (cruise power) : 18 [gr/kwh]
Literature :
Handbook of aeronautics Volume II aero-engines page 12
DISCLAIMER Above calculations are based on published data, they must be
regarded as indication not as facts.
Calculated performance and weight may not correspond with actual weights
and performances and are assumptions for which no responsibility can be taken.
Calculations are as accurate as possible, they can be fine-tuned when more data
is available, you are welcome to give suggestions and additional information
so we can improve our program. For copyright on drawings/photographs/
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(c) B van der Zalm 01 January 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4