Description and convergence order analysis of the finite element-volume spatial discretization method

Overview & Synopsis

This paper reviews the Finite Element-Volume spatial discretization method on tetrahedral meshes implemented in the TrioCFD code. TrioCFD is a computational fluid dynamics software specifically designed for simulating turbulent flows and heat transfer, with a primary focus on nuclear engineering applications. Its versatility also extends to a wide range of engineering applications. This paper presents the principles of Finite Element-Volume discretization and conducts an analysis of its properties and convergence orders. The time scheme can be explicit or semi-implicit, and the velocity and pressure are updated based on a projection-correction scheme. The discretization ensures local mass conservation, second-order convergence for velocity, and first-order convergence for pressure. Moreover, a super-convergence is achieved in two-dimension when the source term is a gradient. The accuracy and convergence rate of the numerical method is rigorously assessed in a variety of two- and three-dimensional test cases, including steady Stokes and Navier-Stokes problems with manufactured solutions. The classical lid-driven cavity flow is also addressed, and the results of comparisons between the solutions from the present numerical method and the results of reference literature are provided.