Improved boundary conditions for viscous, reacting, compressible flows

Sutherland, James C.; Kennedy, Christopher

doi:10.1016/s0021-9991(03)00328-0

Cited by 156 publications

(95 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…about the validation of the present DNS code in both zero and non-zero pressure gradient turbulent boundary layer flows. Navier-Stokes characteristic boundary conditions (NSCBCs) are implemented based on the original formulation of Poinsot & Lele (1992) and on the later improvements described in Sutherland & Kennedy (2003), Yoo et al (2005) and Yoo & Im (2007). The boundary conditions are non-reflecting at the inflow (x = 0) and outflow (x = L x ) planes (thereby ensuring that spurious pressure waves can exit the domain), no-slip isothermal solid surface at the wall boundaries (y = 0 and y = L y ), and periodic in the spanwise direction (z = 0 and z = L z ).…”

Section: Dns Of Flashback In Turbulent Channel Flowmentioning

confidence: 99%

Direct numerical simulation of premixed flame boundary layer flashback in turbulent channel flow

et al. 2012

View full text Add to dashboard Cite

Direct numerical simulations are performed to investigate the transient upstream propagation (flashback) of premixed hydrogen–air flames in the boundary layer of a fully developed turbulent channel flow. Results show that the well-known near-wall velocity fluctuations pattern found in turbulent boundary layers triggers wrinkling of the initially flat flame sheet as it starts propagating against the main flow direction, and that the structure of the characteristic streaks of the turbulent boundary layer ultimately has an important impact on the resulting flame shape and on its propagation mechanism. It is observed that the leading edges of the upstream-propagating premixed flame are always located in the near-wall region of the channel and assume the shape of several smooth, curved bulges propagating upstream side by side in the spanwise direction and convex towards the reactant side of the flame. These leading-edge flame bulges are separated by thin regions of spiky flame cusps pointing towards the product side at the trailing edges of the flame. Analysis of the instantaneous velocity fields clearly reveals the existence, on the reactant side of the flame sheet, of backflow pockets that extend well above the wall-quenching distance. There is a strong correspondence between each of the backflow pockets and a leading edge convex flame bulge. Likewise, high-speed streaks of fast flowing fluid are found to be always colocated with the spiky flame cusps pointing towards the product side of the flame. It is suggested that the origin of the formation of the backflow pockets, along with the subsequent mutual feedback mechanism, is due to the interaction of the approaching streaky turbulent flow pattern with the Darrieus–Landau hydrodynamic instability and pressure fluctuations triggered by the flame sheet. Moreover, the presence of the backflow pockets, coupled with the associated hydrodynamic instability and pressure–flow field interaction, greatly facilitate flame propagation in turbulent boundary layers and ultimately results in high flashback velocities that increase proportionately with pressure.

show abstract

Section: Dns Of Flashback In Turbulent Channel Flowmentioning

confidence: 99%

Direct numerical simulation of premixed flame boundary layer flashback in turbulent channel flow

et al. 2012

View full text Add to dashboard Cite

show abstract

“…On the other hand, the boundary conditions represent the requirements to be met by the solution x (l, t) at the boundary points of Ω. In general, these conditions may take the form of a linear combination of the Dirichlet and Neumann boundary conditions, as the so-called boundary conditions of the third kind (Dooge and Napiorkowski, 1987;Christofides and Daoutidis, 1997;Sutherland and Kennedy, 2003;Ancona and Coclite, 2005). For the class of hyperbolic systems considered, we assume the Dirichlet boundary conditions, which can be written in the following compact way (see Xu and Sallet, 2002;Diagne et al, 2012):…”

Section: 2mentioning

confidence: 99%

A general transfer function representation for a class of hyperbolic distributed parameter systems

Bartecki

2013

International Journal of Applied Mathematics and Computer Science

View full text Add to dashboard Cite

Results of transfer function analysis for a class of distributed parameter systems described by dissipative hyperbolic partial differential equations defined on a one-dimensional spatial domain are presented. For the case of two boundary inputs, the closed-form expressions for the individual elements of the 2×2 transfer function matrix are derived both in the exponential and in the hyperbolic form, based on the decoupled canonical representation of the system. Some important properties of the transfer functions considered are pointed out based on the existing results of semigroup theory. The influence of the location of the boundary inputs on the transfer function representation is demonstrated. The pole-zero as well as frequency response analyses are also performed. The discussion is illustrated with a practical example of a shell and tube heat exchanger operating in parallel-and countercurrent-flow modes.

show abstract

“…This can have adverse effects on the reactions rates of species, and can over estimate the calculated energy release for the given conditions. Since the first development of the Navier-Stokes characteristic boundary conditions (NSCBC) for reacting flows [8], Sutherland and Kennedy [11] was the first to recognize that reactive source terms in the conservation equations must be accounted for in the NSCBC formulation in order to describe the correct acoustic behavior at the boundary. This observation subsequently has led to a comprehensive NSCBC formulation for general boundaries with nonuniform convection, viscous diffusion, and reaction effects [8,9].…”

Section: Navier-stokes Characteristic Boundary Conditions For Spray-lmentioning

confidence: 99%

“…Since additional sources of momentum, energy, and mass add to the complexity of the gas phase equations, the source terms at the primitive variable have been reformulated and implemented. Following the detailed derivation by Appendix of Sutherland and Kennedy [11], the modified source terms for NSCBC formulation resulting from the droplet evaporation are written as:…”

Section: Navier-stokes Characteristic Boundary Conditions For Spray-lmentioning

confidence: 99%

“…Aside from the usual computational challenges associated with combustion DNS, the problem under study has posed additional difficulties. These include correct conservative properties in the implementation of the Lagrangian spray model [6,7] into the Eulerian gas-phase flow solver, and the development of accurate and robust characteristic boundary conditions for reacting flows developed in previous studies [8][9][10][11][12][13] to account for the effects of spray evaporation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Direct Numerical Simulation of Non-Premixed Flame Extinction by Water Spray

Arias

Narayanan

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

View full text Add to dashboard Cite

The interaction of turbulent nonpremixed flames with fine water spray is studied using direct numerical simulations (DNS) with detailed chemistry. The study is of practical importance in fire safety devices that operate in the mist regime, as well as an inexpensive temperature control mechanism for gas turbines. The implemented computational methods for the Lagrangian particle-in-cell spray droplet representation and modified characteristic boundary conditions for spray-laden reacting flows are briefly described. The model configuration is a two dimensional ethylene-air counterflow diffusion flame at moderate strain rate. Laminar and turbulent flame simulations are performed with various water loading conditions. Comparison of various simulation cases highlights the flame weakening characteristics due to fluid dynamic strain and water spray evaporation. A modified mixture fraction variable defined in our earlier study [1] is applied to provide correct physical description of the flame response by accurately capturing the flame locations. Findings from this study provide a better understanding of interaction between thermal and aerodynamic quenching in turbulent flame dynamics.

show abstract

Improved boundary conditions for viscous, reacting, compressible flows

Cited by 156 publications

References 28 publications

Direct numerical simulation of premixed flame boundary layer flashback in turbulent channel flow

Direct numerical simulation of premixed flame boundary layer flashback in turbulent channel flow

A general transfer function representation for a class of hyperbolic distributed parameter systems

Direct Numerical Simulation of Non-Premixed Flame Extinction by Water Spray

Contact Info

Product

Resources

About