Mach Number

[Pugilistic Animus]

EAS *[p2*d1*T1/p1d2*T2]^.5/c0 [T2/T1],...the missing ' T's' and they stay missing

[Pugilistic Animus]

Remember! Mathematics and Physics Like God, Sees Every Secret Thing, Whether Good or Evil

[Microburst2002]

Hi PA

Why are you focused in dynamic pressure in the Lift ecuation?

Dynamic pressure is a magnitude of its own, whether there is an airplane or not. S and CL have nothing to do with it, except if you are calculating the required q for a given airplane, configuration and Lift.

q= 1/2 * rho * TAS^2

EAS = TAS * sqr root of sigma. By definition.

Now:
MN = TAS/(sqr root of theta)
MN= [EAS/sqr root of sigma]/(sqr root of theta)
since delta=sigma*theta
MN= EAS/sqr root of delta----------No T, of course.

(where sigma= rho/1,225 kg/m3, delta=p/1013,25 Hpa and theta= T/288ēK)

[Pugilistic Animus]

Dynamic pressure is a magnitude of its own,

how could something be dynamic if it does not exist?

TAS squared and density

delta = hPa/Hpa*K/K= no dimensions at all....???

TAS squared and density

---I think I put that in



I'm still not sure what you mean????

do you mean?

OS wrote; Thus, all performance is predicated upon EAS, which (unfortunately) is presented to the pilot as CAS.

PA

[Microburst2002]

The relative magnitudes delta, sigma and theta have no dimensions. They are ratios: for instance, delta=0.5 means 50% of standard sea level pressure.

What I mean is what I said in previous posts:
- We agree, basically. T has nothing to do with the EAS, MN and FL relation.
- EAS is not a velocity.

I just pointed out that dynamic pressure, which of course exists, is a magnitude per se. It's mathematical formula has nothing to do with S or CL. It is only a matter of air velocity and density. You seem to extract q from the Lift formula, which is not correct in this case in my opinion.

[Pugilistic Animus]

Microburst2002 my bad: I meant just 'q' it is a force of habit to put SCl I get what you mean now

you fly by EAS: the wing flies by TAS

PA

[Pugilistic Animus]

Seeing as of late how the engineering laboratory reports that I have to grade have been coming back with some 'interesting' derivations',...in considering these 'interesting formulations' I sometimes find the student's 'original source'

and the 'new source' in the topic of aerodynamics is mostly wrong,...and even when it is somewhat ok the symbolgy used in the equations is mostly WRONG


it seems 'this source' was used on here to 'formulate a 'newstyle derivation'
I think a better source for non-engineers was profered by_ JT and actaully his explainations are quite simpler and not in a muddle as is ususal with this 'new style' source ,...

generally after the report receives an F

I will always allow it to be redone for a better grade--and that 'source' forever disappears



here's much better advice

For pilot use, probably one of the more useful texts is Hurt's Aerodynamics for Naval Aviators. This has the usual pilot relevant equations for note but is a very easy simplified read on the story. Readily available in just about every technical bookstore flogging aeroplane stuff.

PA