Research lines
The Group works in different research lines, the main ones being
Combustion at microscale
The correct design and development of microcombustors needs of a thorough understanding of the mass and heat transfer processes within a small volumen. The characteristic time of the chemical reactions involved limits the combustion process itself. The Group develops fundamental studies on the dynamics and propagation of flames in channels and ducts of small size (diameter of the order of millimeter) and flames propagating through confined geometries (Hele-Shaw cells). We make use of numerical simulations and mathematical analysis of the full governing equations with detailed chemistry and transport or by the use of simple models and global kinetics. We are interested to improve the understanding of the mechanism involved in the flame instabilities at microscale.
Numerical and asymptotic studies of laminar and turbulent flames
The fundamental study of laminar and turbulent flames is one of the most theoretical research line of the Group. The disparity of the time and length scales encountered typically in the combustion problems serves to simplify the solution, often by asymptotic methods, and help to identify the relevant mechanisms involved. For example, the lean flammability limit condition of the planar premixed flame can be calculated analytically by the use of asymptotic methods when the flame speed is a suficiently small parameter. In most cases, a proper combination of analytical and numerical tools shows excellent results.
Turbulent combustion modeling
In this research line, we work on the improvement and predictivity of numerical simulation tools for combustion systems at industrial scale. The Group develops new models, such as "flamelets", for turbulent flames. These models presume that laminar-flame-like structures underlie in turbulent flames and, as a result, a tabulation of laminar flames can be incorporated with relatively computational cost to the numerical simulations of the chemitry-turbulence interactions. The models developed in the Unit can be used both in comercial codes and open-source codes, improving the productivity and viability.
Chemical kinetic reduction
One of the most important point for the chemical kinetic reduction is the incorporation in turbulent flame calculations, where the use of detailed chemistry can make the problem intractable due to the enormous computational cost. Although tabulation methods (in PDF models) have demonstrated their potential, the use of reduced kinetic schemes is the simplest alternative method for solving reactive DNS and LES simulations. The reduced kinetics is also useful in studies of flame stability and dynamics in laminar configurations. One of the Group's research line is the chemical kinetic reduction, in particular for hydrogen, syngas (H2/CO mixtures) and more recently for methane, based on steady-state and partial equilibrium hypothesis.