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 ...

In the natural history of type 2 diabetes, pancreatic insulin secretion is progressively depleted and metabolic control worsens. Treatment of these patients usually starts with diet and exercise, with subsequent use of oral glucose-lowering drugs, finally ending with insulin therapy to achieve good metabolic control. When there is still endogenous insulin secretion, the combination of insulin a...

The design and operation of a novel optically accessible high-pressure combustion apparatus is presented. The apparatus provides optical access for the direct observation of the morphology and development of premixed reaction fronts at elevated pressures. A chamber-in-chamber design with an innovative connecting system allows for safe, constant-pressure measurements, alleviating the extreme ove...

0021-9991/$ see front matter 2012 Elsevier Inc http://dx.doi.org/10.1016/j.jcp.2012.06.029 ⇑ Corresponding author. E-mail address: [email protected] (M. Ihme). Many combustion models that are based on the flamelet paradigm employ a reaction progress variable. While such a progress variable is well defined for one-step reaction kinetics, this is typically not the case for complex chemical mechanis...

This work performs an analysis of plasma-assisted non-premixed H2-air flames in Y-shaped micro combustors the presence field emission dielectric barrier discharge (FE-DBD) plasma actuators. The combustion, flow, and heat transfer characteristics are numerically investigated, effect sinusoidal discharges on combustion performance is examined at various equivalence ratios (φ). A coupled chemical ...

Multiple flame regimes are encountered in industrial combustion chambers, where premixed, stratified and non-premixed regions may coexist. To obtain a predictive tool for pollutant formation predictions, chemical modeling must take into account the influence of such complex structure. The objective this article is to apply compare two reduced chemistry models on both laminar turbulent multi-reg...

New combustion systems based on ultra-lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat, and stationary power generation. However, lean premixed flames are highly susceptible to fluiddynamical combustion instabilities, making robust and reliable systems difficult to design. Lowswirl burners are emerging as an important tech...

A new turbulent, premixed, stagnation swirl flame (SSF) is used to synthesize titanium dioxide (TiO2) nanopowders. Synthesis conditions under two flame modes, i.e., burnerand substrate-stabilized SSF, are investigated, for the same equivalence ratio, but different inert-dilution ratios. The particles (collected on the substrate) have high anatase purity, with mean diameters of 5–10 nm, determin...

In order to evaluate transport properties in turbulent premixed flames, a propagating turbulent premixed flame in an incoming homogeneous isotropic turbulence is directly simulated assuming a single-step irreversible Arrhenius-type reaction. To investigate the production of turbulent kinetic energy in the flame region, Favre averaged transport equation of turbulent kinetic energy along streamwi...

Liquid-fueled burners are used in a number of propulsion devices ranging from internal combustion engines to gas turbines. The structure of spray flames is quite complex and involves a wide range of time and spatial scales in both premixed and non-premixed modes (Williams 1965; Luo et al. 2011). A number of spray-combustion regimes can be observed experimentally in canonical scenarios of practi...