Spray of gelled propellants from an impinging-jet injector under different temperatures

This paper presents the results of an experimental study on the spray characteristics of gelled propellant from an impinging jet injector under different liquid temperatures. A high-speed camera was used to record detailed information about the liquid sheet breakup process and spray development. The rheological characteristics of the gel simulant under different temperatures were tested. It was found that the consistency coefficient decreases and the flow index increases as the liquid temperature increases. The flow characteristics and spray patterns for injectors with tapered orifices and straight orifices were tested, respectively. Because the injection of fluid through tapered orifices can decrease the viscosity of the fluid, the mass flow rate is increased and the liquid sheet behaves more unstably for injector with tapered orifices. The influence of liquid temperature on the mass flow rate for both injectors is minor. The spray photos showed that the liquid sheet is more unstable and easier to break up at higher temperature for both injectors. Generally, the liquid sheet breakup length decreases and the disturbance wavelength increases as the liquid temperature increases.