* Hadi Bordbar (Dr.)*,

Staff Scientist,

https://people.aalto.fi/en/hadi_bordbar

Laboratory of Fire Safety Engineering,

Department of Civil Engineering,

Aalto University, Finland.

Adjunct professor (Docent) in radiative heat transfer in energy conversion processes

Laboratory of Modeling of Energy Systems,

School of Energy Systems,

Lappeenranta University of Technology, Finland.

**Keynote Speech:** **High Fidelity Modeling of** **Spectral Thermal Radiation in Combustion Systems**

One of the main challenges in numerical modeling of thermal radiation in combustion systems is that radiative properties of media are usually strongly spectral dependent. It is more significant in gaseous media where the absorption coefficient erratically changes with wavelength. In reality the thermal radiation spectrum of a hot gas consists of hundreds to thousands of absorption lines associated with transitions between vibration-rotation energy levels of the molecules in infrared spectrum. In order to find the exact solution of radiative heat transfer in such systems, the radiative transfer equation should be solved for each of these lines. This is called line by line calculations which requires enormous computational resources and therefore is not currently feasible except for benchmarking of approximate models in very simple cases. Hence, during the last few decades a number of simplified numerical models have been developed aiming at providing accurate and still feasible ways to include the complex spectral features of gas radiative heat transfer in overall modeling of energy processes. These methods have their own limitations, capabilities and requirements.

In this keynote speech, we will review the current state of the art in modeling of spectral radiative heat transfer in combustion systems. Different models will be introduced including line by line, narrow band, and global models such as WSGG, k-distribution, box model and full-spectrum correlated-k method (FSCKM). The importance of spectral radiation heat transfer in several applications including circulating fluidized bed boilers, oxygen-fired combustion and fire dynamics modeling will be addressed and discussed