Browsing by Subject "Vorticity"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Coupling Viscous Vorticity Equation (VISVE) method with OpenFOAM to predict turbulent flow around 2-D hydrofoils and cylinders
    (2019-06-19) Yao, Hao; Kinnas, Spyros A.
    The VIScous Vorticity Equation (VISVE) method has already been applied to solve the laminar flow around a cylinder and a hydrofoil at low Reynolds numbers. This method is more computationally efficient and spatially compact than a viscous flow method based on primitive variables. However, the VISVE method fails at high Reynolds numbers due to the effects of turbulence. In this thesis, a synchronous coupling method was developed to couple the VISVE and a turbulence model in OpenFOAM, enabling the VISVE method to solve the turbulent flow at high Reynolds numbers in a 2-D hydrofoil case and a 2-D cylinder case. The velocity, vorticity, and pressure calculated by the coupling method agree well with the results obtained by a RANS method.
  • Thumbnail Image
    Item
    VISVE, a vorticity based model applied to 2-D hydrofoils in cavitating conditions
    (2020-09-11) Iliopoulos, Konstantinos; Kinnas, Spyros A.
    In this study, the VIScous Vorticity Equation (VISVE) method was applied to predict flow around 2-D hydrofoils in cavitating conditions. The DIVergence of velocity Equation (DIVE) was added to extend the method to compressible flows and coupled with VISVE to predict the partial cavitating flow. The flow was modeled as a homogeneous mixture of vapor and liquid with the vapor volume fraction parameter determining their concentrations inside the volume and an additional transport equation for the vapor volume fraction to predict the partial cavitating flow around 2-D hydrofoils. The VISVE method was designed to be both spatially compact and numerically efficient in comparison with the commonly used Reynolds Averaged Navier-Stokes (RANS) models. Cavity shapes and pressure from the VISVE model were compared with those from a commercial RANS solver to assess the accuracy of the numerical results. With the validation of the 2-D VISVE model, VISVE shows the prospective to model the 3D wetted and cavitating flow.