The characteristics of triple flames in a hydrogen–air mixing layer are studied using direct numerical simulation with detailed chemistry. Triple flames are initiated by imposing a temperature ignition source in the center of a scalar mixing layer of nonuniform thickness, thereby forming a pair of freely propagating triple flames. Two different fuel streams are studied: pure hydrogen and hydrog...

Experimental and numerical techniques to characterize the response of premixed methane-air flames to acoustic waves are discussed and applied to a multi-slit Bunsen burner. The steady flame shape, flame front kinematics and flow field of acoustically exited flames, as well as the flame transfer function and matrix are computed. The numerical results are compared with experiments. The influence ...

Purpose The purpose of this paper is to study turbulent flow separation at the airfoil trailing edge. This work aims improve knowledge stall phenomenon by creating a QDNS database for NACA412 airfoil. Design/methodology/approach Quasi-DNS simulations NACA 4412 in pre-stall conditions have been completed. Reynolds number based on chord and freestream velocity equal 0.35 million, Mach 0.117. Tran...

Kernel P systems (or kP systems) bring together relevant features from several P systems flavours into a unified kernel model which allows solving complex problems using a straightforward code programming approach. kPWorkbench is a software suite enabling specification, parsing and simulation of kP systems models defined in the kernel P– Lingua (or kP-Lingua) programming language. It has been s...

Modern high speed aerospace propulsion relies on the development of scramjet engines significantly. Design of a supersonic combustor involves the potential problems of proper mixing, flame holding as well as flame stabilization within the very short period. Many techniques were introduced to overcome these problems, of which cavity flame holders has evolved as one of the prominent among them. T...

Direct numerical simulation (DNS) of combustion in globally lean non-homogeneous propane-air mixtures has been performed for several initial distributions of non-homogeneities. Results have shown a strong influence of the scale and asymmetry of this distribution on both the combustion efficiency and thermal NO production, in accordance with experimental results. The simulations also have made p...

Direct numerical simulation (DNS) is used to study auto–ignition of turbulent diffusion flames. A novel, all–Mach number algorithm developed by Doom et al is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H2 and Air from Mueller at el. 2 Simulations of three dimensional turbulent diffusion flames are performed. Isotropic turbulence is superimposed on an unstrain...

Changes in flow strain and mixture composition on the order of a flame time scale are characteristic of many practical combustion processes. Accurately predicting the unsteady reponse of burning to these changes requires detailed modeling of species transport and chemical kinetics. This thesis formulates a detailed one-dimensional computational model for arbitrary unsteady conditions of strain ...

Numerical simulations are performed to study the mechanism of deflagration detonation transition (DDT) in a pre-/main-chamber combustion system with stoichiometric ethylene–oxygen mixture. A Godunov algorithm, fifth-order space, and third-order time, is used solve fully compressible Navier–Stokes equations on dynamically adapting mesh. single-step, calibrated chemical diffusive model described ...

asimulation-optimization approach is proposed for replenishment planning andshelf space allocation. the customers’ demand is divided into fixed andvariable demand. each customer follows a given path while shopping in thestore. by dividing the store space into several zones and calculating therelated substantial and random utilities, an analytical equation is proposedfor the probability of zone ...