Spectral Techniques for Solving PDE Stability Model of Vortex Rope
For researchers in hydraulic turbine stability, this is an incremental application of known spectral methods to a specific flow model.
The paper applies spectral methods (L2-projection and collocation) to study hydrodynamic instability of swirling flow in Francis turbines, validating results against existing literature with good agreement.
In this paper spectral methods are applied to investigate the hydrodynamic instability of swirling flow with application to Francis hydraulic turbine. Spectral methods imply representing the problem solution as truncated series of smooth global functions. An L2 - projection and the collocation methods are developed assessing both analytically methodology and computational techniques using symbolic and numerical conversions. Remarks concerning the efficiency and the accuracy of each method in this case are presented. The model of the trailing vortex is used to validate the numerical algorithms with existing results in the literature. All the results are compared to existing ones and they prove to agree quite well. The advantages of using this methods in flow control problems are pointed out.