In the last decades, the enormous growth in portable electronics applications has stimulated research in lightweight and reliable power sources. In this technological niche, the idea of developing miniaturized turbomachinery to serve as portable power sources is attractive, especially in view of the much higher power density of a small turbogas generator in comparison with conventional chemical batteries. The potential social impact of an eventual commercialization of such “nano-devices” is enormous, but the technological and phenomenological complexity of the design and manufacturing of ultra-small machines (with a rotor diameter of the order of 1 cm) poses difficult problems, because some of the well-established design procedures for large and medium scale machines do not seem to be applicable as such at these extremely reduced scales. In this work the design and performance of a miniaturized gas turbine with a tip diameter of about 10 mm is examined from a thermo-fluiddynamic point of view. An extensive series of CFD simulations allows for the quantification of the losses at the resulting low Reynolds numbers (∼4600 in the stator and ∼1500 in the rotor) on the single-curvature geometry imposed by manufacturing constraints. The geometry of the blades is “optimized” on the basis of an entropy generation rate analysis, and the capabilities and limitations of conventional design strategies are assessed.

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