Experimental and numerical work has been carried out to determine the wall heat load at the liner structure of a model gas turbine combustion chamber. Measured cross-sectional profiles of the velocity and temperature field inside the chamber could be used to validate various CFD calculations of the combustion flow. It turned out that only a special treatment of the thermal boundary conditions at all liner walls would actually lead to appropriate values of the wall heat flux. Radiation modeling included two radiative properties models (SG single gray gas and WSSG weighted sum of gray gases) and three radiation transport models (P1, DT discrete transfer, MC Monte Carlo). The performance of the WSGG model has been assessed with charts and the impact of the radiation on the liner wall temperature distribution has been studied. The experimental values are matched within 3% deviation with the best combination of transport and radiation property models. The radiation contributes to 20-30% of the total wall heat flux. The present approach enables Siemens PG to access the thermal design of combustors more precisely.Copyright © 2007 by ASME