| Wave rotors as a family of unsteady-flow devices have shown unique capabilities to enhance the performance and operating characteristics of a variety of engines and machinery utilizing thermodynamic cycles. The wave rotor is an unsteady-flow machine that utilizes compression and expansion waves to exchange energy between fluids with different pressures. The first part of this study presents several thermodynamic cycle analyses proving the performance improvement of small gas turbines (microturbines) by implementing various advantageous four-port wave rotor topping cycles. General performance maps are generated showing the design space and optima for baseline and topped engines. In the second part of this work, a one-dimensional analytical gasdynamic model of the high-pressure phase is suggested to calculate flow characteristics inside the wave rotor channels. Useful design parameters such as port widths and rotor size are determined by computing transit times of the waves traveling inside the channels. Reasonable agreement has been found comparing the predicted results of the analytical design procedure with the available numerical data. Using the commercial software FLUENT, some CFD simulations are performed showing that commonly available CFD software can be utilized for wave rotor simulations and to support their design. Overall, the predicted results are in good agreement with established wave rotor theories. Finally, several innovative wave rotor concepts and designs including have been studied. |
