IK-3 Ikarus

[Laurelix]

IK-3: (1938-1939 models)

Empty Weight: 2077kg
Loaded Weight: 2518kg
Wing Area: 16.50m2
Engine: HS.12Y-29
810hp at Sea Level (Military Power)
890hp at Sea Level (WEP)
910hp at 3600m (Military Power)
-
Max Speed:
421km/h at Sea Level (Military Power)
434km/h at Sea Level (WEP)
527km/h at 5400m (Military Power)
-
Rate of Climb: (Military Power)
Time to 5000m: ~7:00
-
Stall Speed: (SL, No Flaps, 2518kg weight)
150km/h IAS
-
Armament:
1x 20mm HS.404 (60 rounds total)
2x 7.92 mm Browning (1000 rounds total)
-
Maximum Safe Dive Limit:
650km/h IAS

———

IK-3: (Models 1940-1941)

Empty Weight: 2170kg
Loaded Weight: 2630kg
Wing Area: 16.50m2
Engine: HS.12Y-29
810hp at Sea Level (Military Power)
890hp at Sea Level (WEP)
910hp at 3600m (Military Power)
-
Max Speed:
438km/h at Sea Level (Military Power)
452km/h at Sea Level (WEP)
544km/h at 5400m (Military Power)
-
Rate or Climb: (Military Power)
Time to 5000m: ~7:10
-
Stall Speed: (SL, No Flaps, 2630kg weight)
153km/h IAS
-
Armament:
1x 20mm MG/FF (60 Rounds Total)
2x 7.92mm Browning (1000 rounds total)
-
Maximum Safe Dive Limit:
650km/h IAS

———

IK-3 (DB-601A)

Unfortunately I can't find an data on this version so I'm going to calculate the top speed using same drag coefficient as the 1941 production version to get close estimate.

Empty Weight: ???
Loaded Weight: ???
Wing Area: 16.50m2
Engine: DB-601A
910hp at SL (Military Power)
990hp at SL (WEP)
1040hp at 2750m (WEP)
960hp at 4500m (Military Power)
-
Max Speed: (Military Power / WEP)
Sea Level: 455kph / 468kph
1000m: 477kph / 491kph
2000m: 500kph / 510kph
3000m: 521kph / 531kph
4000m: 535kph / 545kph
5000m: 550kph / 561kph
6000m: 553kph / 556kph
-
Rate of Climb: (Military Power)
Time to 5000m: ???
-
Stall Speed:
???
-
Armament:
1x 20mm MG/FF (60 Rounds Total)
2x 7.92mm Browning (1000 rounds total)
-
Maximum Safe Dive Limit:
650km/h IAS

———

IK-3 (VK-105PF)

Unfortunately I can't find an data on this version so I'm going to calculate the top speed using same drag coefficient as the 1941 production version to get close estimate.

Empty Weight: ???
Loaded Weight: ???
Wing Area: 16.50m2
Engine: VK-105PF
1210hp at SL (Max Power)
1180hp at 2700m (Max Power)
-
Max Speed: (Max Power)
500km/h at Sea Level
527km/h at 1000m
537km/h at 2000m
544km/h at 3000m
563km/h at 4000m
555km/h at 5000m
545km/h at 6000m
-
Rate of Climb: (Max Power)
Time to 5000m: ???
-
Stall Speed:
???
-
Armament:
???
-
Maximum Safe Dive Limit:
650km/h IAS

 

[drgondog]

What Drag Coefficient? At What Reynolds Number? What relationship as a f(RN) will you use to derive CDp at new RN?

One such empirical expression is CDp2 = CDp1 (RN1/RN2)^ 0.11

Correct for Mach number effect? CDPm=CDP1/(1-M^2)^1/2

Without geting into the hairy weeds of Performance estimates, recall that a.) 'zero lift drag' values contained in oh so many publications are the 'CD0' or CDP' values obtained in wind tunnels using a scaled model with a 'scale' Reynolds number based on the MAC of the model.

They are most often uncorrected relative to the 'real' (service condition airplane relative to extremely smooth surface/no gaps,etc.) flight conditions. The Brits were better in this respect when they tabulated real world comparisions - often at 100mph as a reference

Many such references are accompanied by wind tunnel velocities for which the CDPo values are recorded for the major airframe groups to be examined. Some reports will isolate those parasite drag components that relate only to RN, vs those that are subject to Angle of Attack or CL (combat anks, racks, bombs). Collectively they are summed up and then corrected for Mach No.

When one uses a Hoerner methodology, for example, of CDt = CDp + CDi, the CDp is the sum of all of the Parasite Drag (Friction and viscous, including corrections for CL) and already corrected for Mach No. The Point? The calculation of 'Flat Plate Drag' presents interesting results regading combination of friction/form and mach corrected results but doesn't tell you much about different behaviors for different conditions, or the 'why' one aircraft has higher/lower values for same speed/altitudes.

You don't know with some degree of precision the actual parasite drag of the individual components of drag within CDp (incl slipstream effects, increased CL as altitude increases to maintain same airspeed (TAS) at different altittudes).

If you already know this, I apologize for the intrusion.