Aircraft investigation >>>>>>> HOME PAGE

performance calculations for the Junkers Jumo 205C aircraft engine

Junkers Jumo 205C liquid-cooled 6 -cylinder inline engine 600 [hp](447.4 KW)

gear-driven supercharger, constant power to height : 1000 [m] blower ratio : 8.85:1

German engine rating : 600 [PS]

introduction : 1936 country : Germany importance : ***

applications : Junkers Ju.86C-1

max. continuous rating : 600 [hp] (447.4 KW) at 2400 [rpm] at 1000 [m] above sea level

take-off power : 700 [hp] (522.0 [KW]) at 2500 [rpm]

reduction : 0.633 , valvetrain : SOHC

weight engine(s) dry with reduction gear : 570.0 [kg] = 1.27 [kg/KW]

General information : One of the few Diesel engines used in aircraft. It had 12 opposing

pistons, sharing 6 cylinders. Two-stroke engine. No valves, only exhaust and intake

port openings in the cylinder wall. Two crankshafts, linked with camwheels to each

other. The lower crankshaft driving all accessories.

fuel system : direct injection fuel type : Diesel oil system : dry sump

engine starter type :

bore : 105.0 [mm] stroke : 2 x 160.0 [mm]

compression ratio: 17.00 :1

published stroke volume (Vs displacement): 16.620 [litre]

compression volume (Vc): 1.039 [litre]

total volume (Vt): 17.664 [litre]

calculated engine height : 139 [cm]

calculated engine length: 1.41 [m]

specific power : 26.9 [kW/litre]

torque : 1780 [Nm]

engine weight/volume : 34.3 : [kg/litre]

average piston speed (Cm): 12.5 [m/s]

***************************************************************************

intake manifold absolute pressure (MAP) at 1000 [m] altitude Pi : 0.95 [kg/cm2]

mean engine pressure (M.E.P.) at 1000 [m] altitude Pm : 7.60 [kg/cm2]

compression pressure at 1000 [m] altitude Pc: 32.79 [kg/cm2]

estimated combustion pressure at 1000 [m] Pe : 130.99 [kg/cm2]

estimated combustion pressure at 1000 [m] Pe : 173.06 [kg/cm2]

exhaust pressure at 1000 [m] Pu : 3.69 [kg/cm^2 ]

**************************************************************************

compression-start temperature at 1000 [m] Tic: 341 [°K] (68 [°C])

compression-end temperature at 1000 [m] Tc: 685 [°K] (412 [°C])

average engine wall temperature at 1000 [m] : 476 [K] (202 [°C])

caloric combustion temperature at 1000 [m] Tec: 2375 [°K] (2102 [°C])

polytroph combustion temperature at 1000 [m] Tep : 2736 [°K] (2463 [°C])

estimated combustion temperature at 1000 [m] Te (T4): 2539 [°K] (2266 [°C])

polytrope expansion-end temperature at 1000 [m] Tup: 1038 [°K] (765 [°C])

exhaust stroke end temperature at 1000 [m] Tu: 1007 [°K] (734 [°C])

*********************************************************************************

Thermal efficiency Nth : 0.508 [ ]

Mechanical efficiency Nm : 0.630 [ ]

Thermo-dynamic efficiency Ntd : 0.320 [ ]

design hours : 180 [hr] time between overhaul : 24 [hr]

fuel consumption optimum mixture at 2400.00 [rpm] at 1000 [m]: 112.84 [kg/hr]

specific fuel consumption thermo-dynamic : 188 [gr/epk] = 252 [gr/kwh]

estimated specific fuel consumption (cruise power) at 1000 [m] optimum mixture : 231

[gr/kwh]

specific fuel consumption at 1000 [m] at 2400 [rpm] with mixture :13.0 :1 : 252 [gr/kwh]

specific fuel consumption (volume*rpm) at 2400 [rpm] : 252 [gr/kwh]

estimated specific oil consumption (cruise power) : 15 [gr/kwh]

Literature :

Wikipedia

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/

content please mail to below mail address

(c) B van der Zalm 28 November 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4

notes :