A computational study is performed to investigate the effects of mixture composition oscillations on a strained premixed methane/air flame. The problem is of practical relevance in direct-injection spark-ignition (DISI) engines and gas-turbines, in which premixed flames propagate through temporally and spatially stratified mixture field. The primary focus of the study is to identify the dynamic...

Dimethyl ether (DME) is considered a promising alternative to diesel fuel in compression-ignition engines because of low particulate and NOx emissions along with high thermal efficiencies as well as improved auto-ignition characteristics due to its high cetane number. Recently, DME also has been selected as a prospective fuel candidate for the validation of turbulent combustion models organized...

Freely propagating and counterflow laminar premixed steady hydrogen/air and methane/air flames are investigated numerically using complex chemistry and detailed transport models. All the transport coefficients in the mixture, including thermal diffusion coefficients, are evaluated using cost-effective, accurate algorithms derived recently by the authors from the kinetic theory of gases. Our num...

Flame stability is a well-known problem in the power industry where low quality fuel fired and combustion conditions change rapidly. Unstable flames often lead to lower efficiency, higher pollutant emissions, other operational problems. Although there are many methods available for flame monitoring characterisation, very few suitable monitoring. This paper presents method quantification of by i...

A large-eddy simulation (LES) of a bluff-body-stabilized flame has been carried out using a new strategy for LES grid generation. The recursive filter-refinement procedure (RFRP) has been used to generate optimized clustering for variable density combustion simulations. A methane–hydrogen fuel-based bluff-body-stabilized experimental configuration has been simulated using state-of-the-art LES a...

Recent experimental investigations of combustion in diesel engines showed that the initial premix burn creates pockets of soot and fuel that must burn out in a diffusion-flame mode in order to complete the combustion [5, 6]. Understanding the final stages of this process is critical to predicting the emissions of soot and NOx. This effort uses numerical simulations to investigate burnout of dif...

Predictions of scalar mixing and the scalar dissipation rate from large-eddy simulations of a piloted nonpremixed methane/air diffusion flame (Sandia flame D) using the Lagrangian-type flamelet model are presented. The results obtained for the unconditionally filtered scalar dissipation rate are qualitatively compared with general observations of scalar mixing from experiments in non-reactive a...

The effects of heat transfer on engineering applications is a fundamental aspect in the design of power and propulsive systems. The heat exchange between fluid and solid parts may reduce the efficiency of the system in situations where temperature peaks and gradients become important. This is the case of gas turbines, combustion engines or cooling of turbine blades. However, this interaction is...

Due to the ever wider use of composite materials within aerospace applications, fireproof tests get recently an increased attention. Numerical simulation is expected in the coming years to accompany engineers in their design work to increase the chance of success in the fireproof certification tests. The current research focuses on the numerical investigation of a premixed methane-air flame imp...

A non-sooting lifted methane/air coflowing non-premixed flame has been studied experimentally and computationally. The flame structure was computed using a model that solves the fully elliptic governing equations, utilizes detailed transport coefficients and a chemical kinetic mechanism with C1 to C6 hydrocarbons, and includes an optically thin radiation submodel. Gas temperature, major species...