14.02.2013 Views

Thesis - Leigh Moody.pdf - Bad Request - Cranfield University

Thesis - Leigh Moody.pdf - Bad Request - Cranfield University

Thesis - Leigh Moody.pdf - Bad Request - Cranfield University

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Appendix E / Earth Geometry<br />

_ _<br />

The polynomial approximation is therefore derived by direct differentiation<br />

of Equation 19.3-2,<br />

∂ ρ<br />

A<br />

ZG<br />

p<br />

19.4 Speed of Sound in Air<br />

−3<br />

−4<br />

ZG ZG<br />

( 7.<br />

4376 x10<br />

− 1.<br />

231x10<br />

⋅ P ) P<br />

∂ P : = − 0.<br />

11477 +<br />

⋅<br />

19-7<br />

p<br />

Equation 19.3-4<br />

The speed of sound in air (at sea level the speed of sound is 340.294 m/s),<br />

SPEED OF SOUND IN AIR (m/sec)<br />

19.5 Mach Number<br />

350<br />

340<br />

330<br />

320<br />

310<br />

300<br />

V : = 1.<br />

4 ⋅ R ⋅ T<br />

A<br />

290<br />

-5 0 5 10 15 20 25 30 35<br />

GEODETIC HEIGHT (km)<br />

Figure 19-4 : Speed of Sound in Air vs Height<br />

The Mach number associated with the speed of sound in air,<br />

M<br />

p<br />

: =<br />

P&<br />

o,<br />

p 0.<br />

0498539 ⋅ P&<br />

: =<br />

V<br />

T<br />

A<br />

g<br />

S<br />

S<br />

o,<br />

p<br />

Equation 19.4-1<br />

Equation 19.5-1<br />

The Mach Number variation with speed, velocity and geodetic height below<br />

11 km,<br />

∂ M<br />

∂ P&<br />

p<br />

G<br />

p<br />

: =<br />

0.<br />

0498539 ∂ P&<br />

⋅<br />

T ∂ P&<br />

S<br />

d,<br />

p<br />

G<br />

p<br />

: =<br />

M<br />

&<br />

G<br />

p ⋅ Pp<br />

2<br />

P&<br />

d,<br />

p<br />

Equation 19.5-2<br />

p

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!