Overview

1. FLUISTCOMFluid Structure Interaction for Combustion Systems ( MRTN-CT-2003-504183)Conjugate Heat Transfer Channel FlowsFluistcom 30-month Meeting June 2006 MülheimD. PanaraInstitut für Verbrennungstechnik, Stuttgart.

2. Overview • Work Overview • Motivation and Structure • Work Done • Turbulent Boundary Layer Response to Pulsating and Oscillating Flow • Isothermal and • Non-Isothermal Flow • Present Work • Unsteady Channel and Pipe Flows with Conjugate Heat Transfer • Code Validation in multi region configuration • Future Work • URANS simulations regarding combustion oscillations in conjunctions with unsteady conjugate heat transfer (M3.5 24-42 months)

3. Work Motivation • FLUISTCOM • Fluid-Structure interactions • In Unsteady Combustion • Regimes Twente Combustion Chamber Test Rig Representative simple pulsating channel

4. Simplified Channel Case T U • General Configuration • Pulsating velocity • Pulsating temperature • Phase shift between temperature and velocity • Effect of solid wall heat capacity (conjugate heat transfer problem) • Natural heat convection to the ambient

5. First Configuration: Isothermal Channel FlowTest case available: Tardu et al. U • Main Targets: • Wall shear stress response to turbulent pulsating and oscillating channel flow • Validity of the use of Wall-Functions in LES and URANS WORK DONE • Results: • Main effect on wall-shear stress phase shift • Main parameter of interest is ls+ • URANS: Low-Reynolds number turbulence model gives quite accurate results • LES: wall-normal resolved grid plus WALE model gives good results • Wall function approach is not accurate for low values of ls+

6. Second Configuration: Non-Isothermal Channel FlowTest case available: Ishino et al. Tw Ti U • Main Targets: • Overall heat transfer • Validity of the use of Wall-Functions in LES and URANS To=? WORK IN PROGRESS • Results: • Main effect expected at high amplitude pulsations • Main parameter of interest is Reb/Rem • Note: • Test case available for laminar flow ( Kim et al. and Hyun)

7. Other Interesting ConfigurationsTest case available: Mansouri et al. Tout Tw=? T U • Main Targets: • Overall heat transfer • Validation of the conjugate heat transfer code with turbulent flow Tb=? FUTURE WORK Test case not available Tout • Main Targets: • Overall heat transfer • Effects of wall heat capacity • Effects of Turbulence model • Valitity of the Reynolds analogy Tw=? T U Tb=?

8. Conjugate Heat TransferCode Modification and Validation • Developed a specific OpenFoam Solver for Conjugate Heat Transfer with multiple domain • Solver Validation • Solid-Solid Configuration • Transient Heat Transfer in Composite Media • Solid-Fluid Configuration • Transient Heat Transfer in Laminar Pipe Flow • Oscillating Temperature in Laminar Channel Flow

9. Code Validation: ConjugateFoamTest case validation one: Transient heat transfer, composite solids • Analytical solution available from Carslaw and Jaeger, Conduction of Heat in Solids • Laplace equation for solid conduction • Multi-Zone solver with BC coupling: Flux Forward, Temperature Backward (FFTB) Analytical solution available from Carslaw and Jaeger, Conduction of Heat in Solids Laplace equation for solid conduction Multi-Zone solver with BC coupling: Flux Forward, Temperature Backward (FFTB)

10. Code Validation: ConjugateFoamTest case validation two: Transient heat transfer, laminar fully developed pipe Analytical solution available from Al-Nimr and Hader Laplace equation for solid conduction Navier-Stokes Equations for Fluid Multi-Zone solver with BC coupling: Flux Forward, Temperature Backward (FFTB)

11. Code Validation: ConjugateFoamTest case validation two: Transient heat transfer, laminar developing pipe Analytical solution available from Al-Nimr and Hader Laplace equation for solid conduction Navier-Stokes Equations for Fluid Multi-Zone solver with BC coupling: Flux Forward, Temperature Backward (FFTB)

12. Code Validation: ConjugateFoamTest case validation two: Oscillating Temperature, Laminar Flow Comparison available from Sucec and Sawant Laplace equation for solid conduction Navier-Stokes Equations for Fluid Multi-Zone solver with BC coupling: Flux Forward, Temperature Backward (FFTB)

13. Future Work:URANS unsteady combustion • Testing OpenFoam in Simple Combustion Chamber Configurations test case: Banhawy et al. Premixed Methane Flame Backward-Facing Step Temperature, Species and Velocity Fields for different value of step height and equivalence ratio.

14. Future Work:URANS unsteady combustion and Conjugate wall heat transfer • Testing the Conjugate Heat Transfer code in Simple Combustion Chamber Configurations. Test case not available Premixed Methane Flame Backward-Facing Step Temperature, Species and Velocity Fields are available for different value of step heights and equivalence ratios. Wall Temperature distribution is not available.

15. Conclusions • The boundary layer response to pulsating and oscillating flow has been investigated: • Isothermal flow • Non-isothermal flow: some work is still in progress • A code for conjugate heat transfer problems has been developed • The code has been validated in various configurations • URANS simulations with conjugate heat transfer and combustion instabilities: • Simple test case: Banhawy Backward-facing step is ready for testing the reacting code capability with and without conjugate heat transfer. • Twente test rig simulation with conjugate heat transfer: to be done.

16. Thanks for the attention..Any questions?

17. The DLR German Aerospace Research Center Space Agency of the Federal Republic of Germany

18. Sites and employees 5.100 employees working in 27 research institutes and facilities n at 8 sites  in 7 field offices. Offices in Brussels, Paris and Washington. Hamburg Neustrelitz Trauen  Berlin- Charlottenburg  Braunschweign Berlin-- n Adlershof nGöttingen nKöln-Porz nBonn Sankt Augustin Darmstadt nLampoldshausen nStuttgart nOberpfaffenhofen Weilheim

19. Aeronautics

20. Aeronautics Covering the entire system of aeronautic transport

21. Aeronautics • Optimizing the performance and the environmental compatibility of the entire aircraft system • Expanding the range of helicopters to all weather conditions • Efficient and environmentally-friendly aircraft engines • Safe and efficient air traffic

22. Space

23. Space Support of all the major components of development work in the German space industry as well as space flight operations and those aspects of space transport relevant to applied research.

24. DLR‘s tasks as a National Space Agency • Defining German space planning on behalf of the federal government • Representing German space-related interests in the international arena, in particular vis-à-vis the ESA • Tendering, award and support of space projects in the context of the National Space Program

25. Transport

26. Transport The aerospace competencies bundled within DLR are to be systematically used to investigate issues related to ground transport.

27. Transport • Resolving issues related to mobility, influencing and coping with the increase in transport • Energy saving, reducing pollutants that affect the climate and are harmful to the health and lowering noise emissions • Accident prevention, reducing the risks to people from accidents

28. Energy

29. Energy DLR’s energy research concentrates on areas of relevance to the energy efficiency and large-scale research.

30. Energy • Efficient, environmentally compatible fossil power plants (turbo machines, combustion chambers, heat exchangers) • Solar-thermal power plant technology, solar chemistry, solar heat storage • Low- and high temperature fuel cell technology • System analysis and technology assessment

31. nHamburg Berlin-- n Adlershof nGöttingen nKöln-Porz Lampoldshausen n / Stuttgart nOberpfaffenhofen Human resources development and promoting the next generation • Further development of HR policy instruments to increase employee motivation • Systematic recruitment of junior staff • Conveying the fascination of mobility and space flight to the next generation • Representation in European organizations and promoting staff exchanges with industry and other national and international partners

32. National networking • Strengthening DLR’s regional presence • More intensive cooperation with universities, other research institutions and industry • Improving customer relations with ministries and cooperation with project management agencies

33. Participation in the Helmholtz Association • Success in obtaining program-oriented funding from the Helmholtz Association • Added value from support from the Helmholtz Association • Helping to shape the organizational development process

34. World -governments, agencies, industry, science, customers, partners, etc. Europe National and international networking Germany - Industry, research ministry, other ministries, scientific community, Federal Ministry of Economics and Technology, Helmholtz Association

35. European networking • Success in obtaining program funding from the European Union • Core formation in Europe for clearly defined strengthening of technical expertise and competitiveness • Expand the ability to determine the direction taken at European level

36. International networking • Orienting bilateral cooperation • Multilateral cooperation in determining the framework and marketing of DLR products • Further developing instruments of international cooperation