Contains H2, CO and unburned components of high-temperature plume of rocket engine, then injected into the atmosphere, continue to carry out the oxidation reaction in the plume near field region with the volume in the plume of oxygen in the air, two times burning. The afterburning is an important cause of infrared radiation intensification of propellant plume, which increases the temperature of the flame and changes the components of the gas, thus enhancing the infrared radiation intensity of the flame. . Two the combustion numerical using chemical reaction mechanism involving HO2 intermediate reaction, the study confirmed that HO2 is a key intermediate, plays a decisive role to trigger early response, on afterburning temperature and flow concentration distribution effect. A finite rate chemical reaction model is used to describe the two burning phenomenon in high temperature plume. In this paper, a numerical simulation of the flame flow field and radiative transfer is carried out for the afterburning phenomenon. The effects of afterburning on the composition, temperature and infrared radiation of the plume are obtained by comparison.
SE-Workbench-EO as an advanced platform of IR scene simulation was introduced. The methods and application of ship IR scene simulation were studied based on SE-Workbench-EO. An infrared scene model of the ship target with the atmosphere and sea surface background is set up. Based on this model, the infrared radiation of the ship scene in the wavebands of 3-5μm and 8-12μm is analyzed. A complete process is achieved which contains model analysis, scene modeling and infrared imaging. It provided references to the infrared scene simulation of the ship and other targets.
Hypersonic body moving in the atmosphere will suffer high temperature reacting flows which will emit complex radiation. Theoretical calculation was taken in this paper for a hypersonic non-ablative sphere. Hypersonic flow around the sphere was simulated using 9 species chemical kinetic and two temperature thermal non-equilibrium model. Based on this simulated flow field, the LOS method is used to solve radiative transfer and line-by-line model is used to calculate the spectrum from molecular and atoms in mid-infrared. The spectra from different components have been analyzed one by one. The calculation founds out that atom N and O diatomic molecule NO and bremsstrahlung will be important radiation source in this pure air hypersonic flow field. The radiation from hypersonic flow field has been analyzed in both high pressure environment and low pressure environment.
Aerodynamic heating is one of important factors affecting hypersonic aircraft design. The Direct Simulation Monte Carlo method (DSMC) has evolved years into a powerful numerical technique for the computation of complex, non-equilibrium gas flows. In atmospheric target, non-equilibrium conditions occur at high altitude and in regions of flow fields with small length scales. In this paper, the theoretical basis of the DSMC technique is discussed. In addition, the methods used in DSMC are described for simulation of high temperature, real gas effects and gas-surface interactions. Combined with the solution of heat transfer in material, heat-flux distribution and temperature distribution of the different shape structures was calculated in rarefied conditions.
The influences of complex refractive index and particle diameter distribution on the spectral transmittance are studied by MIE scatter theory, the spectrum correlation problem of spectral transmittance in different cases is analyzed, the feasibility that using a single point of spectral transmittance to estimate other points is discussed. The results demonstrate that, Refractive index has a great influence on the spectral selectivity, Absorption index however has little effect on it; the particle diameter distributions have a great influence on spectral transmittance, if only contains a kind of particle, with little difference of particle diameter distribution, can be through a single point of spectral transmittance extrapolation other spectral transmittance, but if the difference is significant, is not feasible
The infrared characteristic of the trails produced by solid propellants is introduced in this article. The
mechanism of the trails’ infrared radiation is analyzed, and a special measurement on the trails’ infrared radiation is
implemented with a scaled solid engine. Some useful characteristic data about the trails’ infrared radiation and
transmission and motion is obtained through the measurement. Furthermore, the author puts forward some research
aspects to discuss about the trails’ infrared characteristic.