Abstract: A micro-turbine engine, consisting of at least a compressor, combustor, and turbine, is a complicated fluid flow device that controls the flow rate and thermodynamic properties of a working fluid in order to generate shaft power. Existing micro-turbines are costly to manufacture because they are designed with sophisticated contours and exotic materials. The present invention discloses a method for designing a micro-turbine with stacked layers of structure, each of which is designed with vertically simple geometry such that it can be manufactured using conventional machining technology. The resulting micro-turbine is low cost compared to existing alternatives in the target range of power outputs and applications. The present invention also describes a method for connecting the micro-turbine to an electrical generator to generate power. Lastly, the method for designing the micro-turbine is applied to heat exchangers, Rankine engines, fluid mixers, and other fluid flow devices.