Application of the Multi-Spectral Correlated-k Distribution Model to Multi-Dimensional Rectangular Enclosure Gas Radiation Calculations

2021 ◽  
Vol 16 (3) ◽  
pp. 479-493
Author(s):  
Longfeng Hou
Keyword(s):  
Industrial Applications ◽  
Distribution Model ◽  
Scaling Functions ◽  
Test Cases ◽  
Multidimensional Approach ◽  
Spectral Absorption ◽  
Gas Radiation ◽  
Gaseous Media ◽  
Radiation Modeling ◽  
Approximate Treatment

The Multi-Spectral Correlated-k distribution model (MSCk) is an amelioration of the widely used Ck model. In the MSCk model, the breakdown of correlation assumption used in the original Ck model for non-uniform media is overcome by introducing the clustering of scaling functions. The principle of MSCk model is to group together wavenumbers with respect to the spectral scaling functions—defined as the ratio between spectral absorption coefficients in distinct states—so that the correlation assumption can be considered as exact over the corresponding intervals of wavenumbers. Until now, validations of the MSCk model in 0D and 1D test cases have already been performed in the previous work (Andre, F., Hou, L., Roger, M. and Vaillon, R., 2014. The multispectral gas radiation modeling: A new theoretical framework based on a multidimensional approach to k-distribution methods. Journal of Quantitative Spectroscopy and Radiative Transfer, 147, pp.178–195; Andre, F., Hou, L. and Solovjov, V.P., 2016. An Exact Formulation of k-Distribution Methods in Non-Uniform Gaseous Media and its Approximate Treatment Within the Multi-Spectral Framework. Journal of Physics: Conference Series, 676(1)). However, its application to multi-dimensional configurations (much closer to industrial applications) has not been conducted. Accordingly, in the present paper, we focus our attention on the application of the MSCk model to Multi-dimensional calculations.

Radiation Modeling in Oxy-Fuel Combustion Scenarios

2009 ◽  
Author(s):  
Gautham Krishnamoorthy ◽  
Muhammad Sami ◽  
Stefano Orsino ◽  
Anura Perera ◽  
Mehrdad Shahnam ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Wide Band ◽  
Full Scale ◽  
Radiative Properties ◽  
Band Model ◽  
Particle Radiation ◽  
Gas Radiation ◽  
Gaseous Media ◽  
Wide Band Model ◽  
Radiation Modeling

Three gray models for the radiative properties of gases were examined for their usage in oxy-combustion simulations of a full scale boiler with flue gas recycle. Fully coupled computational fluid dynamic (CFD) simulations of a full scale boiler were carried out employing the weighted-sum-of-gray-gases model (WSGGM) at air burn, dry-recycle and wet-recycle conditions. The resulting thermal and composition fields were then frozen and the radiative properties of the gaseous media recomputed employing the Exponential Wide Band Model (EWBM) and correlations for total emissivities of gas mixtures. It is shown that when high CO2/H2O ratios were encountered within the boiler such as in dry-recycle scenarios, employing emissivity correlations developed for purely CO2 media within the models can result in incorrect gas properties. The errors associated with this can be significant when there are large pockets within the furnace where the gas radiation dominates the particle radiation.

Remote Sensing of High Temperature H2O–CO2 Mixture with the Multi-Spectral Correlated-k Distribution Model

2020 ◽  
Vol 15 (11) ◽  
pp. 1335-1342
Author(s):  
Longfeng Hou
Keyword(s):  
Remote Sensing ◽  
Radiative Heat ◽  
Radiative Properties ◽  
Distribution Model ◽  
Scaling Functions ◽  
Spectral Absorption ◽  
Long Distance ◽  
Sensing Applications ◽  
Remote Sensing Applications

Radiative heat transfer of gas plays an important role in remote sensing applications. Several models have been proposed to estimate the radiative properties of gases. The Line-By-Line (LBL) approach is the most accurate one. However, The Line-By-Line (LBL) approach usually requires excessive computation cost which makes it not applicable for most industrial most applications. Nevertheless, it still plays the role of benchmark reference for the assessment of other models. In this work, we propose the application of the Multi-Spectral Correlated-k distribution model (MSCk) so as to make the simulation of hot jet signature at long distance. In the MSCk model, the breakdown of correlation assumption used in the original Ck model for non-uniform media is overcome by introducing the clustering of scaling functions. The principle of MSCk model is to group together wavenumbers with respect to the spectral scaling functions-defined as the ratio between spectral absorption coefficients in distinct states-so that the correlation assumption can be considered as relatively exact over the corresponding intervals of wavenumbers. Results show that the MSCk model demonstrates better performance compared with the traditional Ck model at nearly an equivalent calculation cost.

Calculation of Radiation Signal of Rocket Plume after Atmospheric Attenuation Using Wide Band K-Distribution Model

2013 ◽  
Vol 295-298 ◽  
pp. 2437-2441
Author(s):  
Xue Mei Yin ◽  
Qiu Yang Ma ◽  
Xue Hong Wu ◽  
Yi Gong ◽  
Yan Li Lu
Keyword(s):  
Remote Sensing ◽  
Rocket Engine ◽  
Wide Band ◽  
Distribution Model ◽  
Climatic Effects ◽  
Radiation Process ◽  
Gas Radiation ◽  
Atmospheric Remote Sensing ◽  
Rocket Plume ◽  
Liquid Rocket

The calculation of the gas radiation process plays an important role in the study of atmospheric remote sensing and climatic effects of greenhouse gas. The remote sensing of rocket plume has important significance for early warning, interception, detection, identification and tracking of flight vehicle. A model was established to calculate the remote sensing signal of rocket plume by wide band k-distribution, the liquid rocket plume remote sensing signals in atmospheric window region and the detectors’ working spectrum are calculated, and the results were compared with the results calculated by line-by-line approach. The results showed that in some of the detectors’ working spectral regions, the wide band k-distribution model can be used for the calculation of the remote sensing of liquid rocket engine exhaust plume.

Practical Learning on Computational Fluid Dynamics at Undergraduate Level

2016 ◽  
Author(s):  
Teresa Parra-Santos ◽  
José M. Molina Jordá ◽  
Gabriel Luna-Sandoval ◽  
Mariano Cacho-Perez ◽  
J. Rubén Pérez
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Engineering Students ◽  
Active Role ◽  
Flow Patterns ◽  
Industrial Applications ◽  
Similar Degree ◽  
Test Cases ◽  
Critical Thought ◽  
Grid Points

This work involves a methodology for Mechanical Engineering students to learn Computational Fluid Dynamics playing an active role. Students carry out a fluid mechanics down scaled projects with the steps of sensibility of mesh, convergence of numerical algorithm, validation of turbulence model and description of flow patterns. Furthermore, they develop their critical thought when they identify weak points susceptible for improvement. The offer of benchmark test cases ranges from head loses, driven cavities, swirling flows, to external aerodynamics. Simplifications to the level of undergraduate courses imply two dimensional simulations and a limited number of grid points. Hence, the assessment is based in coherence of decisions and efficient use of limited resources. A review of the offer of workshops is supplied, such as the Ahmed car, the Roback and Johnson burner, aerodynamics of different NACA airfoils, and different geometries of driven cavities. These are classical test cases of numerical research and a sample of applications in wind energy, industrial furnaces, and lubrication. Parametrization based in geometry, Reynolds number, Pitch angle among other, let simulate different flow patterns with similar degree of difficulty. There is a deeper understanding of the topic when students need to discuss the strategies to accomplish the project, they need to write a technical report and finally they need to justify the evaluation of other works. Also, it is important to link the simplified projects of the workshop with the real world and the industrial applications.

scholarly journals CFD ANALYSIS OF PULVERIZED COAL COMBUSTION IN A BLAST FURNACE TUYERE: COMPARISON BETWEEN WSGG AND GG MODELS FOR RADIATION MODELING

2016 ◽  
Vol 15 (2) ◽  
pp. 60
Author(s):  
C. V. Da Silva ◽  
G. Weber ◽  
F. R. Centeno ◽  
F. H. R. França
Keyword(s):  
Blast Furnace ◽  
Radiation Heat Transfer ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Base Case ◽  
Combustion Gases ◽  
Gas Radiation ◽  
Spectral Models ◽  
Industrial Operations ◽  
Radiation Modeling

Combustion processes are being employed for many years, and remains a major source of energy for industrial operations through the conversion of chemical energy in thermal energy, besides being usually accompanied by formation of pollutants. This work presents a numerical investigation using the software Ansys CFX to model the process of combustion of pulverized coal injected into a blast furnace for production of pig iron making a comparison between WSGG and GG spectral models for gas radiation aim to verify the influence on the radiation heat transfer and the temperature field. Since global coal reserves are being constantly reduced, new techniques using coal are being studied. Among some effective techniques, there is the injection of pulverized coal through a tuyere installed at the bottom of the blast furnace. Thus, among the objectives of this work is to obtain information about the pulverized coal burning process injected. Firstly, it will be employed a North American coal as a base case in order to better understand the involved phenomena. Simulations were made using the actual operating conditions of a blast furnace, which uses atmospheric air enriched with oxygen for burning the coal. The same boundary conditions and operation of other investigations were considered in order to validate the model developed for this work, and so that it can be applied in similar situations, either in assessments or in projects of coal injection systems and combustion in blast furnaces. The results include temperature and velocity fields, oxygen concentration, and the formation of CO and CO2 and they are in agreement with data from literature. Comparing the results of this study with the results obtained in the work (Gu et al., 2010) It observed a qualitative similarity between them and also quantitative. Furthermore, it was found that, in this case, modeling the absorption spectrum of the combustion gases resulting in changes in flame form, but did not significantly alter the magnitude of temperatures, since the walls of the equipment are considered adiabatic.

Through-Flow Analysis of Air-Cooled Gas Turbines

2012 ◽  
Author(s):  
Milan V. Petrovic ◽  
Alexander Wiedermann
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Flow Analysis ◽  
Solution Procedure ◽  
Distribution Model ◽  
Air Cooling ◽  
Test Cases ◽  
Pressure Losses ◽  
Through Flow ◽  
And Performance

This paper describes the development of a new through-flow method for the analysis of axial multistage turbines with cooling by air from compressor bleed. The method is based on a stream function approach and a finite element solution procedure. It includes a high-fidelity loss and deviation model with improved correlations. A radial distribution model of losses and a new spanwise mixing model are applied to simulate 3D flow effects. The calibration of the models is performed by calculation of a number of test cases with different configurations, with the aim of achieving high accuracy and optimum robustness for each of the test cases considered. Various types of cooling air injection were encompassed: film cooling, trailing edge injection and disc/endwall coolant flow. There are two effects of air cooling: (i) increase in mass flow downstream of the injection surface and (ii) reduction of the gas total temperature connected with total pressure losses. For both of these effects, the appropriate 2D models were developed and applied. The code was applied to flow analysis and performance prediction of a newly developed industrial gas turbine. Comparison of the predicted results and measured test data for a number of parameters showed good agreement. The results of the validation confirmed that this method based on calibrated correlations can be considered a reliable tool for flow analysis and parameter variation during the design phase.

The Full-Spectrum Correlated-k Distribution for Thermal Radiation From Molecular Gas-Particulate Mixtures

2001 ◽  
Vol 124 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Michael F. Modest ◽  
Hongmei Zhang
Keyword(s):  
Radiative Transfer ◽  
Solution Method ◽  
Radiative Transfer Equation ◽  
Distribution Model ◽  
Molecular Gas ◽  
Gas Mixture ◽  
Spectral Absorption ◽  
Full Spectrum ◽  
One Dimensional ◽  
Molecular Gases

A new Full-Spectrum Correlated-k Distribution has been developed, which provides an efficient means for accurate radiative transfer calculations in absorbing/emitting molecular gases. The Full-Spectrum Correlated-k Distribution can be used together with any desired solution method to solve the radiative transfer equation for a small number of spectral absorption coefficients, followed by numerical quadrature. It is shown that the Weighted-Sum-of-Gray-Gases model is effectively only a crude implementation of the Full-Spectrum Correlated-k Distribution approach. Within the limits of the Full-Spectrum Correlated-k Distribution model (i.e., an absorption coefficient obeying the so-called “scaling approximation”), the method is exact. This is demonstrated by comparison with line-by-line calculations for a one-dimensional CO2-N2 gas mixture as well as a two-dimensional CO2-H2O-N2 gas mixture with varying temperature and mole fraction fields.

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