Fw190 & Ta152 drag, lift etc.

[tomo pauk]

We've had a discussion at another forum, but one can say that the opinion of a seasoned person is needed here

@HoHun - would you be so kind to add your knowledge towards deciphering the Fw table found here? My simplest explanation that says, for example, that drag of a Fw 190A8 is equal to .485 m^2 is very tempting, but perhaps there are some details to be accounted for that are eluding me.
Thanks in advance

edit: 'drag', not 'Cd0'

 

[Dagger]

Note that the 0.485 m2 in the table is not really the drag coefficient, but the product of drag coefficient Cd0 (or Cw0 in the table) times some area (F in the table).

An actual drag coefficient is always dimensionless.

 

[tomo pauk]

Note that the 0.485 m2 in the table is not really the drag coefficient, but the product of drag coefficient Cd0 (or Cw0 in the table) times some area (F in the table).

An actual drag coefficient is always dimensionless.

Yes, of course you're right.
I'll edit the post.

 

[HoHun]

Hi Tomo,

@HoHun - would you be so kind to add your knowledge towards deciphering the Fw table found here? My simplest explanation that says, for example, that drag of a Fw 190A8 is equal to .485 m^2 is very tempting, but perhaps there are some details to be accounted for that are eluding me.

Hm, what's the specific question? I'm not quite sure what I'm supposed to contribute

Regards,

Henning (HoHun)

 

[P-STICKNEY]

We've had a discussion at another forum, but one can say that the opinion of a seasoned person is needed here

@HoHun - would you be so kind to add your knowledge towards deciphering the Fw table found here? My simplest explanation that says, for example, that drag of a Fw 190A8 is equal to .485 m^2 is very tempting, but perhaps there are some details to be accounted for that are eluding me.
Thanks in advance

edit: 'drag', not 'Cd0'

That would be an Equivalent Profile Area - Usually the product of Zero-Lift Drag Coefficient and some agreed upon reference area (Usually Wing Area). It gives you a quick measure of the overall drag of an airframe - for example, a larger airplane with a low Cd0 can very easily have more drag than a smaller ship with a draggier shape. You get the actual drag by multiplying the EPA by Qbar (The Dynamic Pressure).

 

[Nicknick]

The absolute drag is proportional to that specific area. This is a fictional frontal area which adsorbs all the energy of the incomming air flow. However, in reality no frontal area can adsorb all the energy of the corresponding air flow because the air would simple deviate around it (See https://en.wikipedia.org/wiki/Betz's_law)

 

[tomo pauk]

Hi Tomo,



Hm, what's the specific question? I'm not quite sure what I'm supposed to contribute

Regards,

Henning (HoHun)

I'm mostly interested in your interpretation of the more obscure (for me, at least) items towards the bottom of the table, like 'ca R', 'cw St', 'Fkl/F' (or 'Fkt/F') etc. Also, what should the value '135' sq m should mean in the row that denotes the cooler surface area.

 

[HoHun]

Hi Tomo,

I'm mostly interested in your interpretation of the more obscure (for me, at least) items towards the bottom of the table, like 'ca R', 'cw St', 'Fkl/F' (or 'Fkt/F') etc. Also, what should the value '135' sq m should mean in the row that denotes the cooler surface area.

Well, no way to be sure without the rest of the documentation this table belonged to, but I would think:

- Index "R" - "Reichweite" or "Range"
- Index "A" - "Abflug" or "Take-off"
- Index "St" - "Steigflug" or "Climb"
- F_Kl/F - Fläche der Klappen/Flügelfläche or Area of Flaps/Wing Area
- "135" - I'd have to guess ... maybe radiator depth in mm? With frontal area and wetted area given, that would be another figure of interest with regard to aerodynamics, at least.

Regards,

Henning (HoHun)