Finite volume - space-time discontinuous Galerkin method for the solution of compressible turbulent flow

The aim of this work is to simulate the flow of the passive gas mixture and estimate the resulting concentration of the potentionally dangerous pollutant emmisions. We assume non-stationary compressible gas flow in the gravitational field described by the system of the RANS equations, equipped with the equation for the concentration of additional specie. Due to gravitational force eﬀect we modify the boundary conditions and data resulting admissible situations. The real simulations of the atmospheric flow require the use of the wall functions for the boundary condition simulating the ground surface with given roughness. We show the modification of such wall functions. The computational results are obtained with the own-developed CFD code for the compressible turbulent mixture flow. The originality of this work lies with the special handling of the boundary conditions, and own computational code.

Section: Methodsmentioning

confidence: 99%

The simulation of the atmospheric flow with emmisions

Kynčl

Pelant

2019

“…We use either explicit or implicit finite volume method (FVM) to solve the systems sequentionally. Other possible discretizations were shown in [16,17]. Here we present the discretization of the system (1) using FVM.…”

Section: Methodsmentioning

confidence: 99%

The simulation of the gas flow through the porous media and fences

Kynčl

Pelant

2019

The paper is focused on the numerical simulation of the compressible gas flow through the porous media and fences. We work with the the non-stationary viscous compressible fluid flow, described by the RANS equations. The flow through the porous media is characterized by the loss of momentum. It is possible to use various methods for the simulation of such flow. Here we present the approach with the modification of the source term, and other possibilities using the modification of the face flux. The original approach was presented recently by the authors analysing the modification of the Riemann problem with one-side initial condition, complemented with the Darcy’s law and added inertial loss. Another aim of this paper is the evaluation and estimate of the forces acting on the diﬀusible barrier (fence) with given parameters. The presented examples were obtained with the own-developed code for the solution of the compressible gas flow.

“…One possibility of linearization ofR s ands is via Taylor expansion which is used in our case. For more details see [6].…”

Section: Turbulence Modelmentioning

confidence: 99%

Finite volume - space-time discontinuous Galerkin method for the numerical simulation of compressible turbulent flow in time dependent domains

Česenek

2017

Self Cite

Abstract. The article is concerned with the numerical simulation of the compressible turbulent flow in time dependent domains. The mathematical model of flow is represented by the system of non-stationary ReynoldsAveraged Navier-Stokes (RANS) equations. The motion of the domain occupied by the fluid is taken into account with the aid of the ALE (Arbitrary Lagrangian-Eulerian) formulation of the RANS equations. This RANS system is equipped with two-equation k − ω turbulence model. These two systems of equations are solved separately. Discretization of the RANS system is carried out by the space-time discontinuous Galerkin method which is based on piecewise polynomial discontinuous approximation of the sought solution in space and in time. Discretization of the two-equation k − ω turbulence model is carried out by the implicit finite volume method, which is based on piecewise constant approximation of the sought solution. We present some numerical experiments to demonstrate the applicability of the method using own-developed code.