| It is important to know how the liquid sloshing and vibration of flexible appendageaffect the dynamical behavior of the main body of the spacecraft. The present thesis isabout some study for this aim.In microgravity, the shape of hydrostatic surface of the liquid is meniscus. If the liquidtank is rectangular or revolving symmetric, the shape of the meniscus can be described by asecond order nonlinear differential equation with some unknown parameters, which can besolved by shooting method. Using shooting method, this thesis gives shapes of hydrostaticsurface of the liquid with different Bond numbers, different liquid volume ratios, anddifferent contact angles in these tanks.For rectangular tank, the sloshing frequency and velocity potential can be expressed byFourier series development method and spring-oscillator-damper equivalent model can bebuild by equivalent mechanical principle. Numerical results are given in this thesis. ForCassini tanks, the sloshing frequency, the force and moment of the sloshing to the tank,equivalent mechanical model can also be obtained by characteristic function expansionmethod. Numerical results are given in this thesis.For free or forced sloshing in ellipsoidal tanks or Cassini tanks(the cylindrical part ofthe tank considered as surface part of flat long ellipsoid) in microgravity, variationalprinciple is applied for the derivation of the dynamical model in integral form based on theshape of hydrostatic surface. Analytical expressions of velocity potential and surfacedisplacement are obtained by Laplace equation in terms of Gauss hypergeometric series,and frequency equation and modal equation can be obtained. Numerical results for theeigenfrequency, the response of surface slosh motion, the slosh force and moment, and theequivalent mechanical model to lateral excitation of the tank are discussed. The response ofsurface slosh motion and the stability condition of parametric resonance to longitudinalexcitation of the tank are also discussed. This method is efficient compared to numericalprocedures with dense computational mesh.For the spacecraft with a cylindrical tank in microgravity, the coupling dynamicsequations of the liquid-rigid system are built on the base of considering the shape ofhydrostatic surface of the liquid and introducing the first five modes of the sloshing. TheHopf bifurcations of out-plane modes resulting from changes of dimensionless frequency of the external excitation and mass ratio of the liquid to the rigid are studied. Variations ofHopf bifurcation points with changes of Bond number, the contact angle and its hysteresis,the liquid height, and the frequency ratio of the liquid to the rigid are researched.The attitude maneuver of liquid-filled spacecraft with a cantilever appendage by amomentum wheel is also studied in this thesis. The momentum wheel is used to attitudemaneuver of the spacecraft. The sloshing liquid is modeled as a viscous pendulum and theappendage is modeled by lumped mass method or subsystem method. The attitudedynamics equation of the main body and the swinging equation of the pendulum arederived by the theorem of moment of momentum, and the oscillation equation of theappendage is obtained by Lagrange equation. Two different maneuver strategies aredesigned for the attitude maneuver. One contains a weighting coefficient related nearly withthe wheel angular acceleration, which can be determined by the initial and final state of thesystem and the steady state time of the attitude maneuver. The other one makes the wheel ata constant angular acceleration which can also be determined by the initial and final state ofthe system and the steady state time of the attitude maneuver. Numerical simulationsindicate that the maneuver strategies used are effective for achieving the attitude maneuver.Sensitivity of the residual nutation angle of the spacecraft and the residual transversalangular velocity of the main body is analyzed to some chosen parameters of the system.
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