In this work, we derive a few new advective flux approximation expressions, apply them in a hybrid finite-volume-element (FVE) formulation, and solve the turbulent reacting flow governing equations in the cylindrical frame. To derive these advective-kinetic-based expressions, we benefit from the advantages of a physical influence scheme (PIS) basically, extend it to the cylindrical frame suitably, and approximate the required advective flux terms at the cell faces more accurately. The present numerical scheme not only respects the physics of flow correctly but also resolves the pressure–velocity coupling problem automatically. We also suggest a bi-implicit algorithm to solve the set of coupled turbulent reacting flow governing equations, in which the turbulence and chemistry governing equations are solved simultaneously. To evaluate the accuracy of new derived FVE–PIS expressions, we compare the current solutions with other available numerical solutions and experimental data. The comparisons show that the new derived expressions provide some more advantages over the past numerical approaches in solving turbulent diffusion flame in the cylindrical frame. Indeed, the current method and formulations can be used to solve and analyze the turbulent diffusion flames in the cylindrical coordinates very reliably.

Solving turbulent diffusion flame in cylindrical frame applying an improved advective kinetics scheme

An improved actuator disc model for the numerical prediction of the far-wake region of a horizontal axis wind turbine and its performance

Pressure-dependent weighted-sum-of-gray-gases models for heterogeneous CO2-H2O mixtures at sub- and super-atmospheric pressure

In this work, a hybrid finite-volume-element method is used to solve turbulent reacting flow in a combustion chamber considering detailed chemical kinetics. The hybrid unification enables the solver to treat the reacting flow in very complex geometries and to respect the required physical considerations fully. We employ two-equations standard �-� turbulence model incorporated with suitable wall functions to model the turbulence behavior. Assuming optically-thin gases, radiation effects are taken into account in our simulations. A flamelet combustion model is applied to consider the large detailed chemical kinetics, which can normally occur within combustion processes. Turbulence-chemistry interaction is taken into account via using a suitable probability density function. We extend the physical influence scheme (PIS) to approximate the mixture fraction variance fluxes over the cell faces. The PIS scheme estimates the advection fluxes suitably while respects the physics of flow fully and totally consistent with the flow governing equations. We extend a bi-implicit algorithm to solve all transport equations, i.e., we solve the hydrodynamics equations and thermo-chemical transport equations separately. The current numerical solutions are validated against data collected from measurement. They show great agreement with the experiments.

Numerical Simulation of Turbulent Reacting Flow in a Combustion Chamber Using Detailed Chemical Kinetics

In this work, a hybrid finite element volume FEV method is suitably used to simulate the aerosol dynamics and chemistry of micro/nanoscale soot particulates in a heavily sooting ethylene-air turbulent diffusion flame. In the soot simulation part, we numerically solve the two-equation soot model involving the transport equations for soot number density and soot mass fraction, based on the acetylene-route nucleation. In this regard, the nucleation process is described using a one-step reaction for the soot formation (inception) from acetylene. Considering the complex process of acetylene-route soot nucleation, we extend the classical physical upwind influence scheme to approximate a more accurate soot mass fraction and soot number density fluxes at the cell faces. To solve the transport equations for the first two moments of mixture fraction, we impose large detailed chemical kinetics and the flamelet combustion model. We also consider the turbulence-chemistry interaction via imposing suitable probability density functions PDFs in our formulations. Additionally, we consider the two-equation standard κ-e turbulence model and suitable wall functions to impose the turbulence influences. Assuming an optically thin limit, we take into account the radiation emission of both gaseous mixture and particulate soot parts. The governing equations are solved thorough two different sequential matrices in a bi-implicit manner. Comparing with the measured data, the present solution accurately predicts the temperature and soot volume fraction, which are the key parameters in studying the flame and particulate pollutions.

Extending a Numerical Procedure to Simulate the Micro/Nanoscale Soot Formation in Ethylene-Air Turbulent Flame Using Acetylene-Route Nucleation

We extend a hybrid finite-volume-element (FVE) method to treat the laminar reacting flow in cylindrical coordinates considering the collocation of all chosen primitive variables. To approximate the advection fluxes at the cell faces, we use the upwind-biased physical influence scheme PIS and derive a few new extended expressions applicable in the cylindrical frame. These expressions are derived for both the Navier-Stokes and reactive flow governing equations, of which the latter expressions are considered novel in the finite-volume formulation. To validate our derived expressions, the current results are compared with the experimental data and other available numerical solutions. The results show that the accuracy of the current expressions is better than those derived by the past similar numerical investigators.

Majid Ghafourizadeh

Papers

Extending a Hybrid Finite-Volume-Element Method to Solve Laminar Diffusive Flame

Solving turbulent diffusion flame in cylindrical frame applying an improved advective kinetics scheme

A new bi-implicit finite volume element method for coupled systems of turbulent flow and aerosol-combustion dynamics

Numerical Simulation of Turbulent Reacting Flow in a Combustion Chamber Using Detailed Chemical Kinetics

Extending a Numerical Procedure to Simulate the Micro/Nanoscale Soot Formation in Ethylene-Air Turbulent Flame Using Acetylene-Route Nucleation