Validation of a New Parallel All-Speed CFD Code in a Rule-Based Framework for Multidisciplinary Applications

Abstract

This paper focuses on the validation of a new all-speed Computational Fluid Dynamics (CFD) code called Loci-STREAM. This computational package is not just another CFD solver; rather, it integrates proven numerical methods and state-of-the-art physical models to compute all-speed flows using generalized grids in a novel rule-based programming framework called Loci which allows: (a) seamless integration of multidisciplinary physics in a unified manner, and (b) automatic handling of massively parallel computing. The objective is to be able to routinely simulate problems involving complex geometries requiring large unstructured grids with arbitrary polyhedral cells and complex multidisciplinary physics. As a first step towards achieving this objective, a wide range of model test cases are studied here, including incompressible laminar and turbulent flow cases, inviscid compressible flow cases, compressible turbulent flows with wall heat transfer as well as internal turbulent flows in 3D geometries and unsteady computations. Comparison of the code with experimental and prior benchmark numerical results is done to validate the robustness of the code for flows ranging from incompressible to supersonic regimes. A scalability analysis is performed as well to study the efficiency of parallelization.

Low-Reynolds-Number Aerodynamics of a Flapping Rigid Flat Plate

“…Loci-STREAM [25], used to produce the Navier-Stokes solutions, is a 3-D unstructured pressure-based finite volume solver. It employs implicit firstor second-order time stepping, treats convection terms using the second-order upwind-type scheme [26,27], pressure, and viscous terms using second-order schemes.…”

Effects of Flexibility on the Aerodynamics of a Hovering Flexible Airfoil at Reynolds Number of 100 to 1000

“…The governing equations for the fluids given by Eq. (3) are solved with Loci-STREAM 31,32,33 , which is a threedimensional, unstructured, pressure-based finite volume solver written in a rule-based framework. It employs implicit first or second order time stepping and treats the convection terms using the second order upwind-type scheme and the pressure and viscous terms using second order schemes.…”

Retrospective Cost Adaptive Flow Control Using a Dielectric Barrier Discharge Actuator with Parameter-Dependent Modeling

“…The flow fields are analyzed by solving the incompressible Navier-Stokes equations using the Loci-STREAM 16 , a parallelized pressure-based unstructured finite volume code. Since the ion and electron states are non-equilibrium and the ion temperature is comparable to the neutral fluid, the neutral fluid is treated as being isothermal.…”

“…where the learning rate l    affects the transient performance and the convergence speed of the adaptive control algorithm. Substituting (15) into (16) yields…”