Sharif Digital Repository

In order to test the performance of engines used at high altitudes, a vacuum simulator system is used. In the vacuum test stand the supersonic exhaust diffuser is used to create the vacuum conditions and the automatic discharge of combustion gases into the atmosphere. usually, the exhaust gas temperature of the engine nozzle is much higher than the temperature that steel body of diffuser can stand (above 2500 K). The purpose of this study is to design and analyze a cooling system to protect the diffusers body. In this study, first by comparing different cooling methods, a spray-cooled water treatment method has been selected for the problem. A new algorithm for designing a spray cooling... 

By creating constant volume combustion, the rotating detonation chamber increases efficiency compared to conventional constant pressure chambers. The RDC is smaller and mechanically more straightforward than the other detonation chambers, such as the pulse chamber. In the current research, an RDC with an outer diameter of 76 mm and an inner diameter of 64 mm, using hydrogen and air as fuel and oxidizer, has been successfully tested and data collected in the laboratory. Data acquisition has been made by high-frequency and pressure measurement facilities. In the following, the chamber has been optimized and improved by applying parametric studies (equivalence ratio, mass flow rate, channel...