Evaluation of CFD Methods for Prediction of Total Temperature and Total Pressure Distribution in Gas Turbines

Abstract: This thesis work was performed as a collaboration between the Royal Institute of Technology in Stockholm and Siemens Industrial Turbomachinery in Finspång. It was undertaken with the purpose of investigating the use of CFD methods in ANSYS CFX to predict flow mixing in gas turbines. The results were evaluated against experimental data gathered as part of an international collaboration; The FACTOR project. The experimental data investigated were total temperature and total pressure at nozzle guide vane inlet and outlet. The results thus focus mainly on nozzle guide vane inlet and outlet due to the nature of the available experimental data. The distribution of these parameters was also investigated in the NGV flow channel and on the vane surface, but it is appreciated that any conclusions drawn from these results are speculative in nature due to the lack of experimental data. Any conclusions drawn must be placed in perspective of the evaluation of NGV inlet and outlet, for which experimental data is available. The focus was on the mixing of the total temperature and total pressure in a nozzle guide vane connected to a combustion chamber simulator. The methods investigated were RANS-SST, SBES and LES-WALE. The main conclusions are that the inclusion of a combustion chamber mesh and thus simulating the CC flow increases the accuracy of the nozzle guide vane results for RANS-SST simulations. It is also observed that in general the SBES and LES-WALE method yield highly similar results under the investigated circumstances, and that both these methods show a general improvement over the RANS-SST method.