Radiative Properties Modeling for Complex Objects Using OpenGL

Modelling of flameless oxy-fuel combustion with emphasis on radiative heat transfer for low calorific value blast furnace gas

A weighted-sum-of-gray soot-fractal-aggregates model for nongray heat radiation in the high temperature gas-soot mixture

This paper describes the general properties of complex objects in engineering designs. There are two types of complex objects: (i) the complex structural objects which describe the physical composition of the design, and (ii) the complex functional objects which describe the behavior of the design and its components. Data manipulation operations on complex structural objects are governed by a set of structural invariants. Similarly, the validation of functional abstraction is governed by a set of functional invariants. The structure-function interactions are represented by interaction objects that describe a set of mappings. These three object types constitute the Structure-Function paradigm. The S-F paradigm can be used to represent engineering designs and active environments, monitor manufacturing operations and industrial processes, and carry out simulations.

Enhanced solar radiation absorption by carbon dioxide in thermodynamic nonequilibrium: A computational study

Investigation of radiative heat transfer in fixed bed biomass furnaces

A refined cylinder fire model for thermal radiation calculation from localized fire to exposed horizontal surface

Axisymmetric radiative heat transfer calculations for flows in chemical non-equilibrium

Optimization of High Temperature SiC Volumetric Solar Absorber

Temperature dependent radiative properties of semi-transparent fiberglass-epoxy composite materials from 20 °C to 200 °C

The problem of mutually irradiating conducting fins is considered in this paper. The problem is analyzed under two types of surface models, namely, diffuse-specular (D-S) model and a directional (Dir) radiative surface property model, for various surface roughnesses and RMS slopes. Metal (aluminum) coated and dielectric (Aluminum oxide) coated surfaces are considered as the two extreme cases. Analysis indicates that dielectric coated surfaces are sensitive to the radiative surface property model while metal coated surfaces are insensitive to the surface property model. Irrespective of the surface property model used metal coated surface show a drastic drop in heat flux for even a slight increase in surface roughness.

\n Aims. By means of optical integral field spectroscopy observations, we aim to differentiate and characterize the starburst component in the blue compact dwarf (BCD) galaxy Mrk 1418. In particular we propose to study the stellar and ionized gas morphology, to investigate the ionization mechanism(s) acting in the interstellar medium, and to derive the physical parameters and abundances of\nthe ionized gas.\n Methods. Integral field spectroscopy observations of Mrk 1418 were carried out with the Potsdam multi-aperture spectrophotometer (PMAS) at the 3.5 m telescope at Calar Alto Observatory. The central 16″$\\times$16″ (1.14 $\\times$ 1.14 kpc2 at the distance of Mrk 1418) were mapped with a spatial sampling of 1″; we took data in the 3590-6996 Å spectral range, with a linear dispersion of 3.2 Å per pixel. The seeing was about 1$\\farcs$5.\nFrom these data we built maps of the most prominent emission lines, namely [O <sc>ii</sc>], Hβ, [O <sc>iii</sc>], Hα, [N <sc>ii</sc>], and [S <sc>ii</sc>], as well as of several continuum bands,\nplus maps of the main line ratios: [O <sc>iii</sc>]/Hβ, [N <sc>ii</sc>]/Hα, [S <sc>ii</sc>]/Hα, and Hα/Hβ, and derived the physical parameters and gaseous metal abundances of the different star-forming regions detected in the field of view.\n Results. Mrk 1418 shows a distorted morphology both in the continuum and in the ionized gas maps; the current star- formation episode is taking place in five knots, distributed around the nucleus of the galaxy. The interstellar medium surrounding these knots is photo-ionized by stars, with no clear evidence for other excitation mechanisms. The galaxy displays an inhomogeneous dust distribution, with the high Hα/Hβ ratio in the central areas indicating a large amount of dust. The oxygen abundances derived for the individual star-forming knots are very similar, suggesting that the ionized interstellar medium is chemically homogeneous in O/H over spatial scales of hundreds of \nparsecs. This abundance (Z ≈ 0.4 $Z_{\\odot}$ from the empirical calibrations) places Mrk 1418 among the high metallicity BCD group.\n Conclusions. These findings show the advantages of IFS when investigating the properties of such complex objects as BCDs, with an asymmetric star-forming component. Only a bidimensional mapping of their central regions allows approaching such questions as the star formation processes in BCDs, the star-forming history of the individual starburst knots, or the abundance gradients.\n

Insights into coarse particle optics based on field evidence of particle morphology, chemical composition and internal structure

The radiation property of flue gas in pulverized coal/biomass oxyfuel combustion distinguishes obviously from that in air combustion. Moreover, the particle emissivity and scattering factor can vary during its thermal conversion. Both phenomena challenge the accurate prediction of radiative heat transfer in coal/biomass oxyfuel combustion. As one solution to surmount this challenge, a new efficient exponential wide band model + particle radiation property model is proposed in this work. For validation, the proposed model is compared with other parallel models, and their predictions are compared against experimental data. It is found that the efficient exponential wide band model + particle radiation property model can give reliable predictions at different operating conditions. The maximum relative errors between the prediction and the experimental surface incident radiation are within 7% at the burner outlet and 2.5% at the peak point. Moreover, the iteration time consumptions are 0.55 and 0.87 s for the 0.5 MW case, and 35.45 and 35.66 s for the 600 MW case with the parallel radiation model and the proposed model. After validation, the feasibility and characteristics of the coal/biomass oxyfuel co-combustion process in a 600 MW tangentially fired boiler are predicted. It is found that the boiler can run stably and the CO2 mass fraction in the discharged flue gas can be around 90%.

Radiative transfer technique for retrieving the radiative properties of agricultural soils

Numerical investigation of the effect of soot aggregation on the radiative properties in the infrared region and radiative heat transfer