A Class of Nonlinear Degenerate Integrodifferential Control Systems
In this paper, we study the approximate controllability and noncontrollability for a class of nonlinear degenerate integrodifferential control systems. Based on the property of finite propagation for the disturbances, we prove noncontrollability. We also establish sufficient conditions for approximate controllability of the system in L2(\Omega) . Moreover, we prove the global existence and uniqueness of generalized solutions.
Simulating a radial-inflow turboexpander from its nozzle inlet to the impeller output as the single nozzle, and through theoretic analysis, this thesis concludes two general characteristic models for design and off-design steady-state of the turboexpanders. Based on experiment data, and generalized least squares method is used in imitation of the data, the coefficient solutions which are needed to describe the models have been obtained. Using the model to predict performance of the other two turboexpanders, the results show that the two general characteristic models in this thesis are more accurate and universal. Therefore, in design of turboexpanders, as two important models, they can give a base for optimizing design and off-design characteristic.