Inhaltszusammenfassung

Transition models are an effective tool for modeling the change of the laminar- and turbulent flow regimes on propeller blades. Thereby, improving the physical accuracy when simulating model scale propellers with a significant fraction of laminar flow. In this study, the influence of the 𝛾 − 𝑅𝑒𝜃 transition model, on near-blade cavitation structures and on the underwater-radiated noise is investigated and compared with the frequently used 𝑘 − 𝜔 − 𝑆𝑆𝑇 turbulence model. For cavitation prediction...Transition models are an effective tool for modeling the change of the laminar- and turbulent flow regimes on propeller blades. Thereby, improving the physical accuracy when simulating model scale propellers with a significant fraction of laminar flow. In this study, the influence of the 𝛾 − 𝑅𝑒𝜃 transition model, on near-blade cavitation structures and on the underwater-radiated noise is investigated and compared with the frequently used 𝑘 − 𝜔 − 𝑆𝑆𝑇 turbulence model. For cavitation prediction, the Schnerr-Sauer cavitation model is utilized. The underwater radiated noise is captured by the Ffowcs- Williams-Hawkings acoustic analogy in Kirchhoff formulation. Two propellers in model scale are investigated, the PPTC ́11 benchmark propeller VP1304 and the SINTEF P1595 propeller for which experimental acoustic measurements are available. In order to determine a physically feasible transition point, a turbulence intensity parameter study is carried out, based on the critical Reynolds number. Good agreement with the experiments is achieved for both propeller using RANS approaches. Overall, no significant improvements are obtained using the transition model. However, differences are observed in the radiated noise. Thus, indicating that the laminar boundary layer has a noticeable influence on the noise emission.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Strömungsmechanik, Technische Thermodynamik und Thermische Energietechnik

DDC Sachgruppe:
Ingenieurwissenschaften