Micro gas turbines generally employ uncooled turbine blades and their thrust is limited by the maximum allowable gas temperature. A miniature cooling scheme embodying effusion cooling may significantly enable higher thrust-to-weight ratios. Modern manufacturing capabilities are improving and enabling affordable solutions for innovative cooling techniques. In scope of this work, a quasi 1D effusion cooling model is developed. The model considers the internal duct and effusion holes flow, conjugate heat transfer and the external film coverage. Solid temperature is allowed to vary both in direction of metal shell thickness and the stream-wise direction of the external gas flow. The model is validated against three-dimensional computational fluid dynamics and it is shown that the model can predict main features of the combined internal and effusion cooling in gas turbine blades. As a next step, design optimization is conducted towards minimizing coolant mass flow rate while retaining solid temperature at a prescribed value. Finally, this coolant modeling scheme is implemented for micro gas turbine blades in order to find the preferable effusion holes pitch and diameter distributions. This approach offers a potential to decouple turbine aerodynamics, which dictate the core, from the thermal management provided by the shell. Therefore, as the shell and core manufacturing processes are also separated, the design timeline and development costs of the turbine stage can be reduced.
