RESUMO
The combustion of multi-hole pyrophoric activated metal is solid combustion and the combustion mechanism is quite complex, which is a difficult problem to be solved. Once the pyrophoric activated metal is exposed to air, the oxygen diffuses to the interior of the activated metal within plenty of holes and reacts with it, which enlarges the contact area with oxygen. Consequently, the whole combustion is vigorous and the temperature rises rapidly. To study the combustion mechanism of the chaff, the surface heat balance equation is established in this work by taking Mg as the activated metal. To solve this equation, the chaff adiabatic wall temperature distribution is computed by computational fluid dynamics in the presence of high-speed airflow. Then, the chaff surface temperature distribution is obtained by solving the heat balance equations. Finally, numerical and experimental results obtained via an infrared thermal imager are compared to demonstrate the effectiveness of the established equation.
RESUMO
Spectral distribution of infrared radiation from plume by the method to calculate infrared radiance of the gaze direction in small sight field was calculated. Based on numerical value and form of radiative transfer equation, infrared radiant intensity of the gaze direction was calculated using the Malkmus statistical narrow-band model and CG approach. Flow field and mole fraction distribution were simulated using a FLUENT computational fluid dynamic (CFD) software. Infrared imaging simulation model of hot jet was established. The hot jet's infrared images of liquid rocket engine were generated. The results demonstrate that the method can detect well-resolved fine structure of flow field. And the model is also applicable to calculation and simulation on infrared radiation of hot jet from engine.
