Ammonia is expected to play an important role as a carbon-neutral fuel in the hydrogen economy. Nevertheless, ammonia combustion still suffers from the problems of poor flame stability and high fuel-NOx emission. C&LSL is devoted to gaining fundamental understanding on ammonia flame stablization and NOx formation mechanisms, with a clear target to provide theoretical and technical support for the realization of clean combustion of ammonia in industrial heating and power machinery.

Soot refers to carbonaceous particles that are produced from incomplete combustion of hydrocarbon fuels. Soot emissions have adverse effects on human health and the environment, and are an important contributor to global warming. The formation of soot involves complex physical and chemical processes with a wide range of spatiotemporal scales; related research is a long-term hot issue in the field of combustion. C&LSL is committed to exploring the mechanism of soot generation through a combination of combustion diagnosis and chemical kinetic analysis. Efforts are devoted to optimizing soot formation models, improving the accuracy of soot-related measurement techniques, and providing support for the development of advanced low-emission power systems.

A prerequisite for in-depth analysis of the combustion process is the acquirement of the detailed physical and chemical parameters through advanced measurement technology. C&LSL is committed to the development of combustion diagnostic methods to provide technical support and novel measurement ideas for challenging combustion experiments. Commonly used techniques in C&LSL include: Laser Induced Fluorescence (LIF), Laser Induced Incandescence (LII), Tunable Diode Laser Absorption Spectroscopy (TDLAS), Fourier Transform Infrared Spectroscopy (FTIR), High Repetitive Frequency Particle Image Velocimetry (PIV), Phase Doppler Particle Analysis (PDPA), Scanning-Mobility Particle Size Distribution Analysis (SMPS), Gas Chromatography-Mass Spectrometry (GC-MS), and etc.

Laser spectroscopy is an important technology for environmental monitoring and in-situ combustion diagnostics. It is based on the absorption, dispersion, scattering or fluorescence of the incident laser light due to various linear and nonlinear effects of light-matter interaction. Through the characteristic spectral signal, the temperature, concentration, pressure and velocity of the measured environment can be determined. ​C&LSL combines the principles of spectroscopy, numerical experiments and experimental measurements to carry out high-temperature diagnostic methods based on infrared absorption and dispersion spectroscopy. We also develop new spectroscopy methods for trace gas sensing, high-accuracy high-temperaure measurement and challenging on-site reacting flow measurement for practical propulsion systems and wind tunnels. C&LSL is also interested in development of integrated turn-key sensor systems for commercial applications. Current technology supports the measurement of temperature, pressure, and concentrations of NH3/CO/CO2/H2O/NO/N2O/CH4/C6H6/SOX.

The rapid development of MEMS micro-electromechanical system requires micro-sized energy supply systems. Micro-scale combustion (~mm level), with its high energy density, has promising potentials to be used in future micro-energy systems. Fundamental research of micro-scale combustion is expected to provide important theoretical design guidance for such systems. On one hand, the reduction of the burner size increases heat loss, leading to flame instability and even extinguishment; on the other, it enhances the thermal coupling effect between the flame and the burner wall, inducing unique flame behaviors that are not seen in combustion at conventional scale. C&LSL is interested in investigating various special flame phenomena including FREI, weak flame, and flame-street, both experimentally and computationally.

High-fidelity numerical simulation is essential for analyzing the physical process of combustion. C&LSL is dedicated to the development, testing and application of high-fidelity numerical codes for reacting flow simulations. The scope of application covers the reacting flows with full velocity spectrum from hypersonic to low Mach number. Our work includes the testing of high-precision numerical format, the implementation of adaptive gridding technology, and various physical/chemical models (component mass diffusion model, conjugate heat transfer and etc.). Available codes include the fully compressible NS equation solver Eilmer (developed by the Hypersonic Center of the University of Queensland, Australia, with participation from C&LSL members), the low Mach number combustion solver independently developed under the OpenFOAM framework, and etc.