科研之友
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摘要
Gelled propellants behave as non-Newtonian fluids and are promising for future aerospace application because they combine the advantages of solid propellants with those of liquid propellants. Spray formation of gelled propellants from swirl injectors in which a leaf spring was installed was described by carrying out experiments in a spray test facility and then comparing them with the spray behavior of water. Safety being a consideration, a water-based gel simulant was used in the experiments instead of the gelled propellant. The rheological characteristics of the gel simulant were tested. A high-speed camera was used to record detailed information about the liquid sheet breakup process and spray development. The experiments were performed with injectors of different configurations and leaf springs to test the effect of injector geometry and leaf spring on the spray characteristics. It was found that the spray patterns of gel simulant were qualitatively different from those of Newtonian liquid (water). The identified spray patterns for the gel simulant were columnar jet, twisted swirling sheet, fluid web, and fully developed hollow cone. The spray cone pulsated under some conditions. A nondimensional frequency parameter was defined as the product of the geometric characteristics constant of a swirl injector and Strouhal number. This parameter for both injectors collapses to one constant under different Reynolds numbers. Adding a leaf spring in the swirl chamber tended to decrease the spray angle of the conical liquid sheet and increase the discharge coefficient and mass flow rate. The breakup length of the gel simulant from injectors with a leaf spring was longer than that from injectors without a leaf spring in the measured range of pressure drops; the mean diameter of droplets of water from the injectors with a leaf spring was larger than that from injectors without a leaf spring.
- 出版日期2011
- 单位北京航空航天大学
