"Worldwide demand for power has been growing exponentially, but its production is causing undeniably negative effects; environmental regulations are changing and becoming stricter. The desire for economical but environmentally friendly engines is focusing on toward alternative methods to produce power. "The Wave Disc Engine" (WDE) is a proposed technology to surpass these requirements. The reduction of mechanical parts in the drive train compared with an IC engine and the use of CNG or any other renewable fuel gas make this WDE an attractive technology to generate power. This new engine concept is a radial rotor in which the typical processes of an Internal Combustion Engine (Compression, Combustion, and Expansion) are realized. Several prototypes were built between 2011 and 2013. For torque production, the unsteady expansion process of outflowing combusted gases is harnessed. This is a new engine concept with incipient research, investigating the mechanism to generate power under unsteady-state conditions. This research work focuses on determining factors that contribute to produce torque in radial rotor channels under unsteady-state conditions. Computational fluid dynamic numerical simulations and analytical method were employed in this investigation. The study initially focuses on the influence of channel parameters (width, height and length); and concludes that channel length and pressure side area all influence torque generation. Both length and pressure side area combine to raise the efficiency and power generated. Because of the unsteady expansion of the gas, an alternative approach was used to evaluate the performance. The Exergetic efficiency produced results for the channel geometry and conditions tested in the range of 31 to 67%. In addition to that, the approach revealed between 82 to 89% of the exergy, initially contained in the channel, still has the potential to be converted into torque in subsequent stages. In addition, a zero dimensional macroscopic approximate balance equation was derived based on the first law of thermodynamics to calculate the unsteady generated work from the unsteady expansion process. Results show prolonging the duration of unsteady expansion process enhances the isentropic extracted work toward the maximum value. In addition to that, the gas expands more efficiently at lower pressure ratios. The impact on the tangential force by the parameters: beta angle, area of influence, and static pressure on pressure and suction sides of a constant cross-section channel, are investigated. The first two parameters change inversely but when combined show similar values at each pressure and suction wall location. Also, most of the generated torque was found in zones near the channel outlet. Furthermore, the torque generation composed of the action of two effects: the change of the angular momentum of the fluid within channel and the outflow rate of the angular momentum at the channel outlet is investigated. These two components are referred as unsteady and steady effects respectively based on the mechanism to produce torque. Results show the torque production benefits when the channel opens quickly. The increase of rotational velocity approximates the quick opening. Unsteady effects produce a significant part of the generated torque and the steady effect can be small at high speed."--Pages ii-iii.
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