The new possibilities offered by additive manufacturing (AM) can be exploited in gas turbines to produce a new generation of complex and efficient internal coolant systems. The flexibility offered by this new manufacturing method needs a paradigm shift in the design approach, and a possible solution is offered by topology optimization. The overall goal of this work is to propose an innovative method to design internal channels in gas turbines that fully exploit AM capabilities. The present work contains a new application of a fluid topology sedimentation method to optimize the internal coolant geometries with minimal pressure losses while maximizing the heat exchange. The domain is considered as a porous medium with variable porosity: the solution is represented by the final solid distribution that constitutes the optimized structure. In this work, the governing equations for an incompressible flow in a porous medium are considered together with a conjugate heat transfer equation that includes porosity-dependent thermal diffusivity. An adjoint optimization approach with steepest descent method is used to build the optimization algorithm. The simulations are carried out on three different geometries: a U-bend, a straight duct, and a rectangular box. For the U-bend, a series of splitter is automatically generated by the code, minimizing the stagnation pressure losses. In the straight duct and in the rectangular box, the impact of different choices of the weights and of the definition of the porosity-dependent thermal diffusivity is analyzed. The results show the formation of splitters and bifurcations in the box and “riblike” structures in the straight duct, which enhance the heat transfer.

References

References
1.
Chyu
,
M. K.
, and
Siu
,
S. C.
,
2013
, “
Recent Advances of Internal Cooling Techniques for Gas Turbine Airfoils
,”
ASME J. Therm. Sci. Eng. Appl.
,
5
(
2
), p.
021008
.
2.
Saha
,
K.
, and
Acharja
,
S.
,
2014
, “
Heat Transfer Enhancement Using Angled Grooves as Turbulence Promoters
,”
ASME J. Turbomach.
,
136
(
8
), p.
081004
.
3.
Bunker
,
R. S.
,
2007
, “
Gas Turbine Heat Transfer: Ten Remaining Hot Gas Path Challenges
,”
ASME J. Turbomach.
,
129
(
2
), pp.
193
201
.
4.
Montomoli
,
F.
,
Massini
,
M.
,
Yang
,
H.
, and
Han
,
J. C.
,
2012
, “
The Benefit of High-Conductivity Materials in Film Cooled Turbine Nozzles
,”
Int. J. Heat Fluid Flow
,
34
, pp.
107
116
.
5.
Ford
,
S. L. N.
,
2014
, “
Additive Manufacturing Technology: Potential Implications for U.S. Manufacturing Competitiveness
,”
J. Int. Commerce Econ.
,
6
(
1
), pp.
40
74
.
6.
Royal Academy of Engineering (Great Britain) Staff,
2013
, “
Additive Manufacturing: Opportunities and Constraints. A Summary of a Round Table Forum Held on 23 May 2013
,” Royal Academy of Engineering, London, UK, accessed Apr. 8, 2017, http://www.raeng.org.uk/publications/reports/additive-manufacturing
7.
Ibabe
,
J.
,
Jokinen
,
A.
,
Larkiola
,
J.
, and
Arruabarrena
,
G.
,
2014
, “
Structural Optimization and Additive Manufacturing
,”
Key Eng. Mater.
,
611–612
, pp.
811
817
.
8.
Jones
,
J. B.
,
Wimpenny
,
D. I.
, and
Gibbons
,
G. J.
,
2015
, “
Additive Manufacturing Under Pressure
,”
Rapid Prototyping J.
,
21
(
1
), pp.
89
97
.
9.
Bendsøe
,
M. P.
, and
Kikuchi
,
N.
, 1988, “
Generating Optimal Topologies in Structural Design Using a Homogenization Method
,”
Comp. Methods Appl. Mech. Eng.
,
71
(
2
), pp.
197
224
.
10.
Bendsoe
,
M.
, and
Sigmund
,
O.
,
2004
,
Topology Optimization: Theory, Methods, and Applications
,
Springer
, Berlin.
11.
Dede
,
E. M.
,
2009
, “
Multiphysics Topology Optimization of Heat Transfer and Fluid Flow System
,”
Proceedings of the COMSOL Users Conference
, Boston, MA, Oct. 8, pp. 4–14.
12.
Dede
,
E. M.
,
2011
, “
Experimental Investigation of the Thermal Performance of a Manifold Hierarchical Microchannel Cold Plate
,”
ASME
Paper No. IPACK2011-52023.
13.
Matsumori
,
T.
,
Kondoh
,
T.
,
Kawamoto
,
A.
, and
Nomura
,
T.
,
2013
, “
Topology Optimization for Fluid–Thermal Interaction Problems Under Constant Input Power
,”
Struct. Multidiscip. Optim.
,
47
(
4
), pp.
571
581
.
14.
Marck
,
G.
, and
Privat
,
Y.
,
2014
, “
On Some Shape and Topology Optimization Problems in Conductive and Convective Heat Transfers
,”
An International Conference on Engineering and Applied Sciences Optimization
(
OPTI
),
M.
Papadrakakis
,
M. G.
Karlaftis
, and
N. D.
Lagaros
, eds., Kos Island, Greece, June 4–6, pp. 1640–1657.
15.
Alexandersen
,
J.
,
Aage
,
N.
,
Andreasen
,
C. S.
, and
Sigmund
,
O.
,
2014
, “
Topology Optimisation for Natural Convection Problems
,”
Int. J. Numer. Methods Fluids
,
76
(
10
), pp.
699
721
.
16.
Othmer
,
C.
,
2008
, “
A Continuous Adjoint Formulation for the Computation of Topological and Surface Sensitivities of Ducted Flows
,”
Int. J. Numer. Methods Fluids
,
58
(
8
), pp.
861
877
.
17.
Verstraete
,
T.
,
Coletti
,
F.
,
Bulle
,
J.
,
Vanderwielen
,
T.
, and
Arts
,
T.
,
2013
, “
Optimization of a U-Bend for Minimal Pressure Loss in Internal Cooling Channels—Part I: Numerical Method
,”
ASME J. Turbomach.
,
135
(
5
), p.
051015
.
18.
Klein
,
A.
,
2015
, “
Uncertainty Quantification for Heat Transfer
,” M.Sc. thesis, Imperial College of London, London, UK.
19.
Willeke
,
S.
, and
Verstraete
,
T.
,
2015
, “
Adjoint Optimization of an Internal Cooling Channel U-Bend
,”
ASME
Paper No. GT2015-43423.
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