Inward swirling flamelet model

A flamelet-based model for supersonic combustion

The renewed interest in high-speed flight has recently demonstrated the need for the development of hypersonic air-breathing propulsion systems, i.e., in which the ambient air is used as oxidizer. These systems have long been recognized as the most well-suited for hypersonic propulsion. Although a traditional ramjet is most appropriate for supersonic speeds (Mach 3 to 5), hypersonic speeds (Mac...

A flamelet model for premixed stretched flames

A mass-based stretch rate is introduced. Combining this stretch rate with the conservation equations for premixed flames gives a set of quasi-one-dimensional flamelet equations, which describe the structure and the mass burning rate of these flames. An integral analysis is applied to the flamelet equations and subsequently a general expression for the mass burning rate of stretched flames is de...

Extended flamelet model for LES of non-premixed combustion

A stochastic model of torque in von Karman swirling flow

A stochastic model is derived to predict the turbulent torque produced by a swirling flow. It is a simple Langevin process, with a colored noise. Using the unified colored noise approximation, we derive analytically the PDF of the fluctuations of injected power in two forcing regimes: constant angular velocity or constant applied torque. In the limit of small velocity fluctuations and vanishing...

Flamelet Analysis of Turbulent Combustion

Three-dimensional direct numerical simulations are performed of turbulent combustion of initially spherical flame kernels. The chemistry is described by a progress variable which is attached to a flamelet library. The influence of flame stretch and curvature on the local mass burning rate is studied and compared to an analytical model. It is found that there is a good agreement between the simu...