TY - JOUR
T1 - Conjugate heat transfer characterization in cooling channels
AU - Cukurel, Beni
AU - Arts, Tony
AU - Selcan, Claudio
N1 - Funding Information: Received: December 2012 Tony Arts: Professor Support financially by the Air Force Office of Scientific Research (AFOSR), Grant FA8655-08-1-3048 Funding Information: The authors acknowledge the financial support of the Air Force Office of Scientific Research (AFOSR), Grant FA8655-08-1-3048, supervised by Dr. S. Surampudi and Dr. G. Abate of the European Office of Aerospace Research and Development.
PY - 2012/6
Y1 - 2012/6
N2 - Cooling technology of gas turbine blades, primarily ensured via internal forced convection, is aimed towards withdrawing thermal energy from the airfoil. To promote heat exchange, the walls of internal cooling passages are lined with repeated geometrical flow disturbance elements and surface non-uniformities. Raising the heat transfer at the expense of increased pressure loss; the goal is to obtain the highest possible cooling effectiveness at the lowest possible pressure drop penalty. The cooling channel heat transfer problem involves convection in the fluid domain and conduction in the solid. This coupled behavior is known as conjugate heat transfer. This experimental study models the effects of conduction coupling on convective heat transfer by applying iso-heat-flux boundary condition at the external side of a scaled serpentine passage. Investigations involve local temperature measurements performed by Infrared Thermography over flat and ribbed slab configurations. Nusselt number distributions along the wetted surface are obtained by means of heat flux distributions, computed from an energy balance within the metal domain. For the flat plate experiments, the effect of conjugate boundary condition on heat transfer is estimated to be in the order of 3%. In the ribbed channel case, the normalized Nusselt number distributions are compared with the basic flow features. Contrasting the findings with other conjugate and convective iso-heat-flux literature, a high degree of overall correlation is evident.
AB - Cooling technology of gas turbine blades, primarily ensured via internal forced convection, is aimed towards withdrawing thermal energy from the airfoil. To promote heat exchange, the walls of internal cooling passages are lined with repeated geometrical flow disturbance elements and surface non-uniformities. Raising the heat transfer at the expense of increased pressure loss; the goal is to obtain the highest possible cooling effectiveness at the lowest possible pressure drop penalty. The cooling channel heat transfer problem involves convection in the fluid domain and conduction in the solid. This coupled behavior is known as conjugate heat transfer. This experimental study models the effects of conduction coupling on convective heat transfer by applying iso-heat-flux boundary condition at the external side of a scaled serpentine passage. Investigations involve local temperature measurements performed by Infrared Thermography over flat and ribbed slab configurations. Nusselt number distributions along the wetted surface are obtained by means of heat flux distributions, computed from an energy balance within the metal domain. For the flat plate experiments, the effect of conjugate boundary condition on heat transfer is estimated to be in the order of 3%. In the ribbed channel case, the normalized Nusselt number distributions are compared with the basic flow features. Contrasting the findings with other conjugate and convective iso-heat-flux literature, a high degree of overall correlation is evident.
KW - Conjugate heat transfer
KW - Convection
KW - Infrared Thermography
KW - Turbine cooling channel
UR - http://www.scopus.com/inward/record.url?scp=84861088423&partnerID=8YFLogxK
U2 - https://doi.org/10.1007/s11630-012-0546-1
DO - https://doi.org/10.1007/s11630-012-0546-1
M3 - مقالة
SN - 1003-2169
VL - 21
SP - 286
EP - 294
JO - Journal of Thermal Science
JF - Journal of Thermal Science
IS - 3
ER -