We present a study of the flame-embedding concept, introduced in [1] as an efficient approach for large-eddy simulation of turbulent combustion at high Reynolds and Damköhler numbers. In flame embedding, the combustion zone is modeled as an unsteady flame modified by the local tangential strain rate, with the latter extracted every time step from the flow field simulations. The flame structure ...

During the last decade extensive research has been made at Lund University, Sweden, on a lean premix (prevaporize) combustion concept with burnt gas recirculation and a metallic flame holder. From this concept a new lean premixed natural gas combustion chamber with internal combustion gas recirculation (CGR) has been developed for the V160/SOLO 161 Stirling engines. This combustor has ultra-low...

Experiments were conducted on laminar spray diffusion flames of ethanol/argon burning in oxygen at pressures of 1 and 3 atm. The flames were physically characterized by measuring droplet velocities and sizes by phase-Doppler anemometry, and gas temperature by thin-filament pyrometry and thermocouples. The flames exhibited a cold core, where little vaporization occurred, surrounded by a primary ...

Large-eddy simulation of premixed combustion is a computational challenge, because complex diffusion and reaction processes often occur in very thin layers. The interaction of these processes with turbulence determines the main properties of the flame brush, such as its burning velocity or its thickness. In turbulent flows, the large vortices wrinkle the flame brush and increase its surface, wh...

The effect of electric fields on combustion is well established [1]. However, few studies have been conducted about the effect of magnetic fields on combustion, though the fact that magnetic fields can influence combustion was first realized over one hundred and fifty years ago. As early as 1846, Faraday applied a magnetic field to a flame on a wax taper and observed its tendency to form an equ...

The effect of electric fields on combustion is well established [1]. However, few studies have been conducted about the effect of magnetic fields on combustion, though the fact that magnetic fields can influence combustion was first realized over one hundred and fifty years ago. As early as 1846, Faraday applied a magnetic field to a flame on a wax taper and observed its tendency to form an equ...

According to the characteristics of boiler combustion process, we use image processing technique to extract features that characterize the features of flame. On requirements of good real-time performance boiler burning diagnose system, we develop a set of PC add DSP real-time image acquisition and burning diagnosis system on the 200MW boilers. The results show that the system is simple, practic...

This work focuses upon the effects of DC electric fields on the stability of downward propagating atmospheric pressure premixed propane–air flames under experimental conditions that provide close coupling of the electric field to the flame. With the appropriate electrode geometry, modest applied voltages are shown to drive a stable conical flame first into a wrinkled-laminar flamelet geometry, ...

In recent years, Large Eddy Simulation (LES) has been successfully applied to non-premixed and premixed turbulent combustion problems [1, 2, 3]. In most technical combustion applications, the pure non-premixed or premixed combustion models are no longer valid, since partially premixed combustion has to be taken into account. An example is the stabilization region of a lifted non-premixed flame....

Turbulent multi-phase combustion is encountered in a number of engineering applications, such as internal combustion engines and gas-turbine aircraft engines. Therefore, the ability to perform accurate numerical simulations of these systems is of paramount importance to improve their design and efficiency. However, the underlying physics of spray combustion are extremely complicated. The liquid...