Bf-109 F series radaitors:

[Roland_HUNter]

Greetings!

 

Out of curiosity, I would like to ask, shouldn't a fully open radiator cause air resistance/drag?

F-4:
With the radiator fully open, I can go 540 km/h at sea level.

[Buzzsaw]

Yes, radiators cause drag.... you can go faster with them closed.

 

The F-4 radiator is automatic... also there is a graphics anomaly with auto rads in that they sometimes appear open when they are not.

[Roland_HUNter]

11 hours ago, Buzzsaw said:

Yes, radiators cause drag.... you can go faster with them closed.

 

The F-4 radiator is automatic... also there is a graphics anomaly with auto rads in that they sometimes appear open when they are not.

I opened them manually.

[Roland_HUNter]

11 hours ago, Buzzsaw said:

Yes, radiators cause drag.... you can go faster with them closed.

 

The F-4 radiator is automatic... also there is a graphics anomaly with auto rads in that they sometimes appear open when they are not.

Do you have any information: how much drag it can cause?

Because in BoS the fully opened radiator cause 63 km/h less top speed.

[BENKOE]

Hi, what is the meaning of top speed?

[Roland_HUNter]

544 kmh at summer for F4

[BENKOE]

Hello @Roland_HUNter, enclosed you will find the result of my airspeed trial:

Map: ............................. Land$English_Channel_1940
Aircraft: ........................ Bf109F-4
Outer air temperature:  14.6° Celsius
Altitude above MSL: .... 61m
Max. true airspeed: ..... 543 km/h @ 2655rpm
Water radiator setting: 76% open

Fuel: .............................  144kg

 

Initially, the Bf109F-4 powerplant DB601E could only be operated under certain restrictions (use of take-off/emergency power was prohibited).

From July/August 1941 to February 1942, the F-4 started to appear with no restrictions. The aircraft handbook indicates upper speeds attained of some 670 km/h true airspeed at about 6km AMSL. At that time, the F-4 could be considered truly combat-capable.

 

 

 

 

Edited February 8, 2024 by BENKOE
fact-checking

[Buzzsaw]

3 minutes ago, BENKOE said:

Hello @Roland_HUNter, enclosed you will find the result of my airspeed trial:

Map: ............................. Land$English_Channel_1940
Aircraft: ........................ Bf109F-4
Outer air temperature:  14.6° Celsius
Altitude above MSL: .... 61m
Max. true airspeed: ..... 543 km/h @ 2655rpm
Water radiator setting: 76% open

 

Initially, the Bf109F-4 powerplant DB601E could only be operated under certain restrictions (2700rpm was not allowed).

From July/August 1941 to February 1942, the F-4 started to appear with no restrictions. The aircraft handbook indicates upper speeds attained of some 670 km/h true airspeed at about 6km AMSL. At that time, the F-4 could be considered truly combat-capable.

 

 

 

 

Hello Benkoe

 

The Bf-109F-4's DB-601E was restricted to 1.30 ata until approx. Feb. 1942.  After that it was given clearance to run 1.42 ata.

 

Roland Hunter:

 

Regarding the speed, we will look at the aircraft when we have time.  At this point I believe the modeling for speed is either correct or close.

[BENKOE]

Hello, enclosed you will find the result of another test flight above the Channel.

I have modified the HUD and added the manifold pressure quantity.
All quantities are provided by the 'Full Mission Builder'.

 

In the current version 5.0400, the Bf109F-4 shows a significant performance increase with decreasing flight weight.
Assessing whether and what role the radiators play is difficult.