Flow Coefficient and Reduced Frequency Effects on Wake-Boundary Layer Interaction in Highly Accelerated LPT Cascade
| Autor: | Pietro Zunino, Daniele Simoni, Davide Lengani, Alessandro Nilberto, Daniele Petronio, Marina Ubaldi, Edward Canepa |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
LPT
POD Production of turbulent kinetic energy (TKE) Wake-boundary layer interaction Reduced frequency Energy Engineering and Power Technology Aerospace Engineering 02 engineering and technology Wake 01 natural sciences 010305 fluids & plasmas symbols.namesake 0203 mechanical engineering 0103 physical sciences TJ1-1570 Mechanical engineering and machinery Physics 020301 aerospace & aeronautics Mechanical Engineering Reynolds number Mechanics Boundary layer Particle image velocimetry Cascade Turbulence kinetic energy symbols Flow coefficient |
| Zdroj: | International Journal of Turbomachinery, Propulsion and Power Volume 6 Issue 3 International Journal of Turbomachinery, Propulsion and Power, Vol 6, Iss 32, p 32 (2021) |
| ISSN: | 2504-186X |
| DOI: | 10.3390/ijtpp6030032 |
| Popis: | The paper presents a detailed analysis of particle image velocimetry (PIV) measurements performed in a turbine cascade representative of highly accelerated low-pressure turbine (LPT) blades. Two cameras have been simultaneously used to observe a great portion of the suction side boundary layer with the highest possible spatial resolution, thus allowing us to solve the interaction process between impinging upstream wakes and the blade boundary layer. Four unsteady inflow conditions, characterized by different incoming wake reduced frequencies and flow coefficients, have been examined at fixed Reynolds number. The highly resolved flow fields have been processed to explore reduced frequency and flow coefficient effects on the boundary layer unsteady transition process and, consequently, on loss production. For a deep physical insight on the mechanisms responsible for loss generation, proper orthogonal decomposition (POD) has been applied at different phases of the wake passing period. This has provided the dominant structures affecting the cascade aerodynamics during the wake period. Moreover, the examination of POD modes has allowed us to show the effects induced by the parameter variation on the turbulent kinetic energy production and thus to the unsteady loss production mechanisms. |
| Databáze: | OpenAIRE |
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