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Current research on supercritical carbon dioxide (SCO2) oxy-combustion is lacking studies on the performance of kinetic models. An optimized 13 species kinetic model is proposed in the present work for CH4/O2/CO2 oxy-combustion. This 13 species kinetic model is developed based on the detailed USC Mech II mechanism with the Global Pathway Selection algorithm, and then optimized with a genetic algorithm covering conditions of pressure from 150 atm to 300 atm, temperature from 900 K to 1800 K and equivalence ratio from 0.7 to 1.3. The autoignition of 13 species kinetic model presents less than 12% error relative to that of the USC Mech II. The performance of the proposed kinetic model is evaluated using a generic jet in crossflow combustor. Simulations at identical conditions are conducted in ANSYS Fluent for both the 13 species model and a global 5 species model. Results were then compared to evaluate the sensitivity of these two kinetic models to the CFD simulations. The results show a better mixing between the fuel and the oxygen, a longer autoignition delay and a more reasonable temperature distribution using the 13 species kinetic model. It is indicating the importance of choice on kinetic models in numerical simulation.

Imaging spectrometry plays a significant role in various scientific realms. Although imaging spectrometers based on different schemes have been proposed, the pursuit of compact and high-performance devices is still ongoing. A compact broadband and ultrahigh-resolution imaging spectrometer (CBURIS) is presented, which comprises a microlens array, multiple fiber bundles, a microscope, and a two-dimensional detector array. The principle of the device is to spatially sample and integrate the field information via the front microlens array and then further process with the fiber bundles and imaging system based on the multimode interference theory. From both the theoretical and numerical analysis, this CBURIS design is a superior concept that not only achieves a 0.17° spatial resolution and ultrahigh spectral resolution (resolving power exceeds 2.58 × 106 at 1.55 µm) from the visible to mid-infrared region but also has the advantages of snapshot measurement, thermal stability, and a compact footprint compared with most existing imaging spectrometers.