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

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Chapter 7 / Missile Trajectory Optimisation<br />

_ _<br />

• Missile lateral lift force<br />

ZA<br />

MV MV<br />

FL ( Pm<br />

, P&<br />

o,<br />

m , ΘB<br />

, ΨB<br />

)<br />

• Gravitational acceleration<br />

ZA ZA<br />

g ( P )<br />

Defining,<br />

⎛<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎝<br />

⎛<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎝<br />

T<br />

T<br />

T<br />

147 MV 147 MV 369 MV<br />

( ϕ , ϕ , ϕ )<br />

MV<br />

A<br />

MV<br />

A<br />

MV<br />

A<br />

( 1 )<br />

A<br />

( 4 )<br />

( 7 )<br />

⎞<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎠<br />

,<br />

⎛<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎝<br />

7-5<br />

T<br />

T<br />

T<br />

B<br />

MV<br />

B<br />

MV<br />

B<br />

MV<br />

B<br />

m<br />

( 1 )<br />

( 4 )<br />

( 7 )<br />

⎞<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎠<br />

m<br />

,<br />

B<br />

⎛<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎜<br />

⎝<br />

T<br />

T<br />

T<br />

MV<br />

B<br />

MV<br />

B<br />

MV<br />

B<br />

≡<br />

( 3 )<br />

( 6 )<br />

⎞<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎟<br />

⎠<br />

⎞<br />

( ) ⎟ ⎟⎟⎟⎟⎟⎟<br />

9<br />

The dynamic states evolve according to the vector functional,<br />

X<br />

( ) T<br />

f , f , f , f , f<br />

f : =<br />

Θ Ψ<br />

P<br />

V<br />

M<br />

⎠<br />

Equation 7.2-4<br />

Equation 7.2-5<br />

The missile position with respect to Alignment axes is propagated using,<br />

147<br />

f : = P ⋅ ϕ &<br />

P<br />

o,<br />

m<br />

MV<br />

A<br />

Equation 7.2-6<br />

Transforming the forces acting along the Missile Body axes through the<br />

incidence angles into the Missile Velocity frame, and selecting the missile<br />

velocity along X MV ,<br />

f<br />

MV<br />

m<br />

MV<br />

B<br />

B<br />

m<br />

MV<br />

B<br />

F : = T ⋅ F : = T ⋅ +<br />

V<br />

: =<br />

m<br />

−1<br />

m<br />

⋅<br />

( ) T<br />

XB XB YB ZB<br />

F F , F , F<br />

T<br />

D<br />

L<br />

L<br />

Equation 7.2-7<br />

XB YB ZB 147 MV ZA MV<br />

( ∆F<br />

, F , F ) ⋅ ϕ + g ⋅ T ( 7 )<br />

m<br />

In which the thrust - drag balance is denoted by,<br />

L<br />

XB<br />

m<br />

L<br />

XB<br />

T<br />

∆ F : = F + F<br />

XB<br />

D<br />

When the missile traces a circle in response to lateral acceleration,<br />

B<br />

m<br />

A<br />

Equation 7.2-8<br />

Equation 7.2-9

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