Now showing 1 - 2 of 2
  • Publication
    About dissipative and pseudo port-Hamiltonian formulations of irreversible Newtonian compressible flows
    (2020-01-01)
    Mora, Luis A.
    ;
    Le Gorrec, Yann
    ;
    Matignon, Denis
    ;
    Ramirez, Hector
    ;
    In this paper we consider the physical-based modeling of 3D and 2D Newtonian fluids including thermal effects in order to cope with the first and second principles of thermodynamics. To describe the energy fluxes of non-isentropic fluids we propose a pseudo port-Hamiltonian formulation, which includes the rate of irreversible entropy creation by heat flux. For isentropic fluids, the conversion of kinetic energy into heat by viscous friction is considered as an energy dissipation associated with the rotation and compression of the fluid. Then, a dissipative port-Hamiltonian formulation is derived for this class of fluids. In the 2D case we modify the vorticity operators in order to preserve the structure of the proposed models. Moreover, we show that a description for inviscid or irrotational fluids can be derived from the proposed models under the corresponding assumptions leading to a pseudo or dissipative port-Hamiltonian structures.
    Scopus© Citations 7
  • Publication
    Fluid-Structure Port-Hamiltonian Model for Incompressible Flows in Tubes with Time Varying Geometries
    (2020-01-01)
    Mora, Luis A.
    ;
    Yann, Le Gorrec
    ;
    Ramirez, Hector
    ;
    A simple and scalable finite-dimensional model based on the port-Hamiltonian framework is proposed to describe the fluid–structure interaction in tubes with time-varying geometries. For this purpose, the moving tube wall is described by a set of mass-spring-damper systems while the fluid is considered as a one-dimensional incompressible flow described by the average momentum dynamics in a set of incompressible flow sections. To couple these flow sections small compressible volumes are defined to describe the pressure between two adjacent fluid sections. The fluid-structure coupling is done through a power-preserving interconnection between velocities and forces. The resultant model includes external inputs for the fluid and inputs for external forces over the mechanical part that can be used for control or interconnection purposes. Numerical examples show the accordance of this simplified model with finite-element models reported in the literature.
    Scopus© Citations 5