Optical Diagnostics

Key Research Topics

• High-speed optical diagnostics of reacting flows

• Fuel spray dynamics and atomization processes

• Mixing and ignition phenomena in high-speed combustion

• Soot formation and carbon deposition mechanisms

• Experimental validation of high-fidelity simulations (LES) 

Advanced optical diagnostics play a critical role in understanding complex combustion and reacting flow phenomena occurring in extreme propulsion environments. In high-temperature, high-pressure, and high-speed flows such as those encountered in advanced propulsion systems, conventional measurement techniques are often insufficient to resolve the detailed physics governing fuel injection, mixing, ignition, and combustion processes.

At APEL, we employ state-of-the-art optical measurement techniques to visualize and quantify reacting flows with high spatial and temporal resolution. These diagnostic methods enable non-intrusive measurements of key combustion characteristics, including fuel spray dynamics, mixing processes, flame structure, ignition behavior, and soot or carbon deposition formation. By capturing these phenomena in detail, optical diagnostics provide essential experimental data for understanding the underlying combustion mechanisms.

The experimental datasets obtained from optical diagnostics are closely integrated with high-fidelity numerical simulations such as large-eddy simulations (LES). This combined experimental–computational framework enables rigorous validation of combustion models and improves the predictive capability of simulation tools used in propulsion system design. Through this approach, APEL aims to establish reliable experimental databases for advanced propulsion systems and to contribute to the development of high-performance and clean combustion technologies for aerospace and energy applications.