An active flow control strategy for the suppression of vortex structures behind a circular cylinder
| Autor: | Sridhar Muddada, B.S.V. Patnaik |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Flow visualization
Viscous flow MSBC General Physics and Astronomy Circular cylinders Computational fluid dynamics Vortex shedding Control system analysis Reynolds number Physics::Fluid Dynamics symbols.namesake Potential flow around a circular cylinder Fluid mechanics Active flow control Fluid flow patterns Mathematical Physics Physics Fluids Sensors Vortex flow Mechanics Contacts (fluid mechanics) Navier Stokes equations Vortex Drag Flow patterns Lift (force) Flow control (fluid) Flow control symbols Strouhal number Chaos control CFD Flow fields Actuators Algorithms |
| Zdroj: | IndraStra Global. |
| ISSN: | 2381-3652 |
| Popis: | An algorithm is proposed to model, predict and control vortex shedding behind a circular cylindrical configuration. The main ingredients of the algorithm include multiple-feedback sensors, actuators (with zero net mass injection) and a control strategy. Along with the mass and momentum conservation equations, a control equation is implemented to enable the desired flow control goals. A number of sensors are chosen in the downstream of the body to report the state of the flow. The role of externally controllable actuators on the fluid flow patterns past a circular configuration is assessed. To enable, zero net mass injection, two simple rotary type mechanical actuators are located at 120�, right behind the main cylinder. The popular finite volume based SIMPLE scheme is employed for the numerical calculations. As a precursor, the scheme simulates flow past an isolated cylinder, which is validated over a moderate range of Reynolds numbers. The design parameters of interest such as Strouhal number, drag and lift coefficients etc are used for the purpose of validation. The simulated flow fields are compared against the flow visualization study, which clearly demonstrates the efficacy of the actuators at discrete levels of rotation. The basic character of the flow is completely modified at Uc/U?�=�2.0 and Re = 100, where a complete suppression of vortex shedding is observed. This is tantamount to complete control of all the global instability modes. Fictitious tracer particles are released to visualize the vortex structures in the form of streaklines. The results clearly demonstrate the effectiveness of a rather simple active control algorithm in suppressing the vortex structures. All the relevant fluid flow features of the bluff-body fluid mechanics under the influence of actuators are studied in the sub-critical Reynolds number range of Re = 100-300. � 2009 Elsevier Masson SAS. All rights reserved. |
| Databáze: | OpenAIRE |
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