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 />

APPENDIX F<br />

19 ATMOSPHERIC PROPERTIES<br />

Aerodynamic forces and moments acting on a point are often presented in<br />

normalised form with respect to the local air density and speed. Their<br />

variation with geodetic height is dealt with using functions involving Mach<br />

number, air density and speed of sound, both locally and at sea-level. Airdata<br />

sensors are a direct example of a system requiring these atmospheric<br />

characteristics, and the local air temperature.<br />

This section provides standard expressions for the variation of air density,<br />

pressure, temperature, Mach number and the speed of sound with geodetic<br />

height and speed. The height variation encompasses the Troposphere (-1 km<br />

to 11 km), Stratosphere (11 km to 20 km) and the Chemosphere (20 km to<br />

32 km). The data provided is based on standard equations taken from<br />

Collinson [C.8] .<br />

Missile trajectory optimisation depends on the variation of the external<br />

forces and moments acting on it, and therefore the atmospheric parameter<br />

gradients presented here. For optimisation purposes discontinuities in the<br />

atmospheric parameter gradients are removed by expressing variations in<br />

terms of accurate approximating polynomials.<br />

19-1

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

Saved successfully!

Ooh no, something went wrong!