This research aims to study in a comprehensive way a different power generation cryogenic energy storage cycles and effective strategies for developing an optimized design of small scale nitrogen axial turbines as the expanders for these cycles within the capacities that can be used for small/medium size buildings, rural, and remote off-grid communities. The hybrid open-closed Rankine cycle have been chosen as the case study for nitrogen turbine analysis for expansion ratios ranged from 1.5 to 3. New turbine design methodology has been developed which integrates one dimension preliminary design method (mean-line method) and three dimensional CFD simulations, and expe1imental validation testing. This turbine methodology was expanded to include developing optimization parametrization technique, a parametric study of four different blade configurations (lean, sweep, twist, and bow), and development of a novel dual stage non-repeated annular area small-scale axial nitrogen turbine. In order to validate the CFD simulation, the design methodology, and to investigate the effects of blade height on small-scale axial turbines performance, a test rig using compressed air was developed. Three manufactured axial turbines with different blade heights ( 4mm, 6mm, and 8mm) were manufactured and tested at various operating conditions
