The starting characteristics of thermodynamic undersea vehicle systems are determined by the geometry, size and combustion area of solid propellants, which directly effect liquid propellant pipeline design. It is nece...The starting characteristics of thermodynamic undersea vehicle systems are determined by the geometry, size and combustion area of solid propellants, which directly effect liquid propellant pipeline design. It is necessary to establish accurate burning models for solid propellants. Based on combustion models using powder rings and two different solid ignition grains, namely star-shaped ignition grains and stuffed ignition grains, a mathematic model of the ignition process of the propulsion system was built. With the help of Matlab, a series of calculations were made to determine the effects of different grains on ignition characteristics. The results show that stuffed ignition grain is best suited to be the ignition grain of a thermodynamic undersea vehicle system.展开更多
To study the gas dynamic and heat transfer phenomena inside a single isolated longitudinal solid propellant surface crack,two3-D geometric models with different crack shapes were constructed.Concerning the influence o...To study the gas dynamic and heat transfer phenomena inside a single isolated longitudinal solid propellant surface crack,two3-D geometric models with different crack shapes were constructed.Concerning the influence of propagation of jet from the igniter on the flame spreading phenomena in the crack,flow region around the opening of the crack was also included in the above geometric models.A theoretical framework was then adopted to model the conjugate heat transfer in the combustion channel and the crack cavity.Numerical simulation results indicate that the ignition shock wave can spread into the crack cavity.Extremely high overpressure and pressurization rate were observed along the crack front.It is possible that the crack may propagate before the flame front reaches it.An ignited region located at the crack front near to the channel surface in downstream direction was generated long before the flame front reached the crack opening in both models.展开更多
文摘The starting characteristics of thermodynamic undersea vehicle systems are determined by the geometry, size and combustion area of solid propellants, which directly effect liquid propellant pipeline design. It is necessary to establish accurate burning models for solid propellants. Based on combustion models using powder rings and two different solid ignition grains, namely star-shaped ignition grains and stuffed ignition grains, a mathematic model of the ignition process of the propulsion system was built. With the help of Matlab, a series of calculations were made to determine the effects of different grains on ignition characteristics. The results show that stuffed ignition grain is best suited to be the ignition grain of a thermodynamic undersea vehicle system.
文摘To study the gas dynamic and heat transfer phenomena inside a single isolated longitudinal solid propellant surface crack,two3-D geometric models with different crack shapes were constructed.Concerning the influence of propagation of jet from the igniter on the flame spreading phenomena in the crack,flow region around the opening of the crack was also included in the above geometric models.A theoretical framework was then adopted to model the conjugate heat transfer in the combustion channel and the crack cavity.Numerical simulation results indicate that the ignition shock wave can spread into the crack cavity.Extremely high overpressure and pressurization rate were observed along the crack front.It is possible that the crack may propagate before the flame front reaches it.An ignited region located at the crack front near to the channel surface in downstream direction was generated long before the flame front reached the crack opening in both models.
