| Popis: |
In developing an approach to determining diagnostics for intelligent control of MPD thrusters, two concurrent studies have been carried out: a stability analysis, and a plasma modeling. An advanced technique for derivation of stability requirements of distributed parameter systems based on mathematical theorems of semigroups and groups, equivalent norms, Lyapunov functionals, etc. has been developed. Application of this technique to the MPD thrusters has resulted in control inputs for stabilizability of the system when perturbed from a general equilibrium state of the plasma. A model has been developed for the state of plasma near the cathode of a MPD thruster engine. The region has been divided into collisionless and collisional parts and full account is taken of the non-equilibrium state of the plasma over the entire region. A scheme for solving the set of describing equations based on an interative procedure has been developed. For low and high current inputs, it is expected that the extent of the different regions and the marching conditions in the different regions will change indicating the trends towards the arising of onset instability. Keywords: Plasma dynamics; MPD modeling; Stability; Controllability; Observability; Nonlinear systems; Distributed parameter systems. |
