In this work, a new 3 kWe flameless combustor for hydrogen fuel is designed and analyzed using CFD simulation. The strategy of the design is to provide a large volumetric combustion for hydrogen fuel without significant rise of the temperature. The combustor initial dimensions and specification were obtained from practical design procedures, and then optimized using CFD simulations. A three-dimensional model for the designed combustor is constructed to further analysis of flameless hydrogen combustion and consideration that leads to disappearance of flame-front and flameless combustion. The key design parameters including aerodynamic, temperature at walls and flame, NOx, pressure drop, combustion efficiency for the hydrogen flame is analyzed in the designed combustor. To well demonstrate the combustor, the NOx and entropy destruction and finally energy conversion efficiency, and overall operability in the microturbine cycle of hydrogen flameless combustor is compared with a 3 kWe design counterpart for natural gas. The findings demonstrate that hydrogen flameless combustion is superior to derive the microturbines with significantly lower NOx, and improvements in energy efficiency, and cycle overall efficiency with low wall temperatures guaranteeing the long-term operation of combustor and microturbine parts. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.