1. Copyright © Siemens AG 2007. All rights reserved. Fluistcom Project Meeting Belfast 24th of December FLUISTCOM Exchange Program at SIEMENS-Muelheim Daniele Panara

2. Page 2 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Overview MC Fellow Activity during the Fluistcom Exchange Program in Siemens-Muelheim  Transfer of Knowledge Between Academia and Industry Siemens ITS-Test Rig validation Project Project Status Description Mismatches with Experimental Data New Strategies of Investigation Siemens Experiences Improved Diagonal Swirler Model Fellow Experiences Improved Boundary Layer Modeling Unsteady Wall Heat Transfer Effects Improved Results

3. Page 3 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara ITS Test Rig, V64.3A burner V64.3A burner Air Experimental Results of the Reacting Steady Flow Velocity Measurements (LDA) Temperature Measurements (Thermocouple Probe) Heat Transfer at Combustor Walls (Ceramic Tile with Thermocouples) Flame Front Detection (2D-OH-LIF) Operating Conditions Atmospheric pressure Equivalence Ratio0.5 Premixed Operation with 7% Pilot Gas Injection

4. Page 4 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Turbulence: k-ε Turbulence Model Scalable Wall Functions ( ) Chemistry: Eddy Dissipation Model Two Step Chemistry: CH4, CO, CO2, H2O, N2 Numerical Model Description Original Simulation: Radiation: Discrete Transfer Model Weighted Multigray Sum of Gas Species Fluid Frozen in a Converged Convective Alone Steady State Solution Number of Ray per Element 8 No use of Coarser Radiation Grid Radiation Calculation for each Time Step

5. Page 5 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Inlet BC: Axial Swirler: Velocity Profiles Interpolated Radiation: black body at local T Original Simulation: Numerical Model Description

6. Page 6 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Inlet BC: Diagonal Swirler: Velocity Profiles Interpolated Averaged Premixed Flow Radiation: black body at local T Original Simulation: Numerical Model Description

7. Page 7 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara BC Liner Walls: heat transfer coefficient radiation Original Simulation: t X0X0 X0X0 Numerical Model Description

8. Page 8 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara BC CJHT Liner Wall: Outer Wall Fixed Temperature: radiation Original Simulation: t X0X0 X0X0 BC Outlet: Static Pressure Radiation: black body at averaged exit temperature Numerical Model Description

9. Page 9 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Existing Missmatches Between ITS Experimental Data and Numerical Results Temperature Profile Hot Side Ceramic Tile Flame Temperature Profile X=0.2257 x/D Z=Y=0

10. Page 10 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara New Strategies of Investigation Siemens Experiences Result Sensibility analysis Reactive Flow-Radiation Interaction Radiative outlet properties Temperature Effects on Ceramic Properties Emissivity Conductivity Turbulence Modeling Improved Diagonal Swirler Model Fellow Experiences Improve Boundary Layer Resolution Low Reynolds Number Turbulence Modeling Unsteady Wall Heat Transfer Effects

11. Page 11 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Sensitivity Analysis Radiation: Use of Coarser Grid for Radiation No Frozen Flow, Radiative Solution each 10 Time Steps Lesson Learned Small Effect on Near Flame Temperature Profile No Effect on Wall Temperature Coarsening Rate is Accurate and Effective to Save Computational Time

12. Page 12 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Sensitivity Analysis Radiation: Effect of Radiative Outlet Temperature Lesson Learned High Impact of Outlet Radiative Boundary Conditions on Wall Temperature No Effect on Near Flame Temperature Profile

13. Page 13 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Sensitivity Analysis Radiation: Effect of the dependence of Ceramic Emittance on Temperature Lesson Learned Small Effect on the Dependence of Ceramic Emittance on Temperature No Effect on Near Flame Temperature Profile Opposite Trend are Found Depending on the Choice of Dependency Law

14. Page 14 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Sensitivity Analysis Radiation: Effect of the Turbulence Modeling (Coarse Grid) Lesson Learned Small Differences Depending on The Choices of Turbulence Modelling Best Results seem to be obtained using k-  SST Open Questions What is the effect of near wall grid refinement?

15. Page 15 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Diagonal Swirler Simulation

16. Page 16 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara New Grid Improved Boundary Layer Resolution For Low Reynolds Number Turbulence Modeling Four Wall CJHT Extended Outlet Section New Diagonal Swirler Inlet Conditions

17. Page 17 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Results Effect of New Geometry + Diagonal Swirler Inlet BC With Radiation

18. Page 18 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Effect of New Geometry + Diagonal Swirler + Radiation Effect of Errors in Thermocouples Positioning

19. Page 19 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Unsteady Computation 20Hz ‘Small’ Oscillations Unsteady effects confined in corner regions

20. Page 20 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Unsteady Computation

21. Page 21 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Unsteady Computation Radiation Non Reflecting BC displacement error: +0.1mm Ceramic Wall Temperature

22. Page 22 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Radiation Non Reflecting BC displacement error: +0.2mm Ceramic Wall Temperature Unsteady Computation

23. Page 23 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Radiation Non Reflecting BC Near Flame Temperature Profile Unsteady Computation

24. Page 24 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Conclusions MC Fellow Activity during the Fluistcom Exchange Program in Siemens-Muelheim  Transfer of Knowledge Between Academia and Industry Considering a wall probe displacement error of +0.2mm good agreement between numerical and experimental results has been found. An improvement of the numerical results in the near flame region has been obtained Some unsteady flow effects have been found but seem to little affect the wall temperature and flame temperature profile

25. Page 25 Jan-06 Copyright © Siemens AG 2007. All rights reserved. PE324Daniele Panara Questions