Pulse detonation turbine engine using turbine shaft speed for monitoring combustor tube operation

The present application provides a shaft speed monitoring system (240) for a pulse detonation combustor (100) with a number of combustion tubes (140) and positioned about a shaft (250) of a pulse detonation turbine engine (200). The shaft speed monitoring system (240) may include one or more shaft sensors (260) positioned about the shaft (250) and a control (270) in communication with the shaft sensors (260) to determine a number of shaft speed fluctuations (275) related to each of the combustion tubes (140).