φ = U a2( b2+ r ) cos θ − U1 b2( r + a2) cos θ,
b2 − a2 rb2 − a2 r

(15)

ψ = −U a2( b2− r ) sin θ − U1 b2( r − a2) sin θ,
b2 − a2 rb2 − a2 r

(16)

and similarly, with velocity components V and V1 along Oy

φ = V a2( b2+ r ) cos θ − V1 b2( r + a2) cos θ,
b2 − a2 rb2 − a2 r

(17)

ψ = V a2( b2− r ) sin θ + V1 b2( r − a2) sin θ,
b2 − a2 rb2 − a2 r

(18)

and then for the resultant motion