In a standard rocket engine, the exhaust gas reaches a very high temperature; thus, the engine walls must be cooled to ensure safe handling. Many cooling methods have been tried and these all have the..
In a standard rocket engine, the exhaust gas reaches a very high temperature; thus, the engine walls must be cooled to ensure safe handling. Many cooling methods have been tried and these all have their benefits and uses, such as regenerative seeing more use in larger rocket nozzles and ablative cooling allowing for modularity. Central to this study is film cooling, the process of injecting a thin layer of liquid fuel onto the nozzle walls to provide insulation from the exhaust gas. Ethanol has been used as fuel and coolant, due to the physical properties of ethanol that allow for relatively clean propulsion and ease of storage and handling in a physical, experimental setting, with liquid oxygen as an oxidizer. In Star-CCM+, a rocket engine model has been subjected to typical ethanol-lox engine exhaust flow. The injection temperature and blowing ratio of the ethanol coolant around the exhaust gas have been varied from low to high values to ensure a wide range of input conditions. It was found that there were negligible differences between the blowing ratio and temperature combinations under incompressible, gaseous, low-blowing ratio conditions. However, it was determined that including the gaseous coolant insulation can prevent 16.35% more heat flux than not using it. Moving forward, research will strive to achieve compressible, supersonic, and liquid coolant conditions and record the relevant data.
