Pressure Gain Combustion (PGC) is considered a possible solution to increase gas turbine cycle efficiency, due to the lower entropy generation in the combustion process. However, the highly unsteady flow produced by PGC makes it more difficult to extract work from its exhaust gas. Any outlet restriction downstream of PGC, such as turbine blades, affects its flow field and may cause additional thermodynamic losses. The unsteadiness in the form of pressure, temperature and velocity vector fluctuations has a negative impact on the operation of conventional turbines. Therefore, evaluating early turbine design parameters for such applications is of great interest. Additionally, experimental measurements and data acquisition present researchers with challenges that have to do mostly with the high temperature exhaust of PGC and the high frequency of its operation. Numerical simulations can provide important insights into PGC exhaust flow and its interaction with turbine blades. In this paper, a Rotating Detonation Combustor (RDC) and a row of nozzle guide vanes have been modeled based on the data from literature and an available experimental setup at TU Berlin. Five guide vane configurations with different geometrical parameters have been modeled. URANS simulations were done for all guide vane arrangements to investigate the effect of solidity and blade type representing different outlet restrictions on the RDC exhaust flow. Total pressure loss and velocity fluctuation were computed upstream and downstream of the vanes. The results analzed the connection between total pressure loss and the vanes solidity and thickness to chord ratio. It is observed that more than 57% of the upstream velocity angle fluctuation amplitude was damped by the vanes. Furthermore, the area reduction was found to be the significant driving factor for damping the velocity angle fluctuations, whether in the form of solidity or thickness on chord ratio increment. A further study of the flow field details revealed that the vane passages act as convergent divergent nozzles in the unsteady flow field and no compression wave exists upstream. This RDC exhaust flow investigation is an important primary step from a turbomachinery standpoint, which provided details of blade behavior in such an unsteady flow field.

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