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Journal articles on the topic 'Numerical slar radiation model'

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Author: Grafiati

Published: 10 March 2023

Last updated: 11 March 2023

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1

Wang, Jian Ping, Bo Chen, Jin Zheng, and Peng Yun Li. "Evaluation on the Thermal Stresses of a Concrete Slab under Solar Radiation." Advanced Materials Research 671-674 (March 2013): 2542–46. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.2542.

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The time-varying temperature field and stress distribution of a concrete roof slab is actively investigated in this study with the aiding of the commercial package ANSYS. Fine finite element model of the concrete slab is constructed and different boundary conditions are applied to obtain the temperature distribution within the slab. The solar radiation model is utilized to estimate the solar radiation received by the slab and the shelter effects are also taken into consideration. The numerical models can successfully predict the structural temperature gradient and thermal stress distribution at different time. The made observations indicate that the simulated temperature variation of the concrete slab based on the solar radiation model agrees well with measurement results. It is seen that the numerical models can successfully predict the structural time-varying thermal effects.

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2

Wang, Jian Ping, Bo Chen, Jin Zheng, and Peng Yun Li. "Analysis on the Daily Temperature Variation of a Concrete Slab under Environmental Effects." Advanced Materials Research 671-674 (March 2013): 2530–34. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.2530.

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The dynamic temperature field of a concrete slab is actively studied in this study with the aiding of the commercial package ANSYS. Fine finite element model of the concrete slab is constructed and different boundary conditions are applied to obtain the temperature distribution within the slab with the aid of the commercial software package ANSYS. The solar radiation model is utilized to estimate the solar radiation received by the slab and the shelter effects are also taken into consideration. The numerical models can successfully predict the structural temperature at different time. The made observations demonstrate that the simulated temperature variation of the concrete slab based on the solar radiation model agrees well with measurement results. It is seen that the numerical models can successfully predict the structural temperature field at different time. The methodology employed in the paper can be applied to other concrete structures as well.

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3

Veselý, Jakub, and Vít Šmilauer. "THERMO-MECHANICAL MODEL FOR CONCRETE PAVEMENT." Acta Polytechnica CTU Proceedings 30 (April 22, 2021): 121–25. http://dx.doi.org/10.14311/app.2021.30.0121.

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This paper describes a numerical thermo-mechanical model for concrete pavement, implemented in OOFEM software. The thermal part is a heat transfer problem with appropriate initial and boundary conditions (sun irradiation, radiation and convection), calibrated from experimental data. Heat release from cement hydration is also included, calibrated for commonly used cements to demonstrate the difference that can be achieved with the binder selection. The mechanical part of the problem is composed of a 3D elastic concrete slab, subsoil Winkler-Pasternak elements and 1D interface elements, allowing separation in tension. The Winkler-Pasternak constants C1 and C2 were firstly determined from TP170 document and refined later from static load tests on the highway. The model validates well temperature field, static load test and provide several useful insight such as feasible time for summer casting, stress/strain fields and slab separation from the base.

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4

Cherkaoui, M., J. L. Dufresne, R. Fournier, J. Y. Grandpeix, and A. Lahellec. "Monte Carlo Simulation of Radiation in Gases With a Narrow-Band Model and a Net-Exchange Formulation." Journal of Heat Transfer 118, no. 2 (May 1, 1996): 401–7. http://dx.doi.org/10.1115/1.2825858.

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The Monte Carlo method is used for simulation of radiative heat transfers in nongray gases. The proposed procedure is based on a Net-Exchange Formulation (NEF). Such a formulation provides an efficient way of systematically fulfilling the reciprocity principle, which avoids some of the major problems usually associated with the Monte Carlo method: Numerical efficiency becomes independent of optical thickness, strongly nonuniform grid sizes can be used with no increase in computation time, and configurations with small temperature differences can be addressed with very good accuracy. The Exchange Monte Carlo Method (EMCM) is detailed for a one-dimensional slab with diffusely or specularly reflecting surfaces.

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5

Heping, Tan, B. Maestre, and M. Lallemand. "Transient and Steady-State Combined Heat Transfer in Semi-Transparent Materials Subjected to a Pulse or a Step Irradiation." Journal of Heat Transfer 113, no. 1 (February 1, 1991): 166–73. http://dx.doi.org/10.1115/1.2910521.

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A numerical analysis based on the finite difference scheme and Hottel’s zonal method generalized by the ray tracing method is carried out to treat the one-dimensional transient and steady-state combined radiative-conductive heat transfer in non-gray Semi-Transparent Materials (STM), especially glasses, subjected to an external pulse or a step of irradiation. Coupling problems are studied for two optical boundary conditions: opaque and vitreous interfaces with specular reflections. The influence of slab thickness, spectral properties of the STM, wavelength of the incident radiation, and diffusivity coefficient are examined. It is pointed out that the application of the laser flash method in thermal metrology may give irrelevant results if the basic heat transfer model is not able to take into account radiative-conductive coupling phenomena. The effect of semi-transparency on the steady-state temperature distribution is also examined for materials ranging from fully opaque to fully transparent.

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6

Rybin, Oleg, and Sergey Shulga. "Feedback magnetization of ultra-low index irradiative structure." Modern Physics Letters B 29, no. 29 (October 25, 2015): 1550179. http://dx.doi.org/10.1142/s0217984915501791.

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Ultra-low refractive index irradiative structure is considered. The structure consists of a patch antenna with the metamaterial slab located on top of the antenna, as superstrate. In this study, ultra-low index phenomenon of the irradiative system is associated with improving the directivity of the patch antenna by putting the metamaterial slab on top of the antenna. The last phenomenon, in turn, is associated with the feedback partial magnetization of Iron inclusions of the slab caused by the radiation from the antenna. Mathematical model for evaluating the complex effective relative permittivity of the irradiative structure is developed. Numerical calculations for complex effective relative permittivity of the irradiative structure and real part of the complex effective relative permeability of the metamaterial slab are done in the study.

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7

Godfrey, Christopher M., and David J. Stensrud. "Soil Temperature and Moisture Errors in Operational Eta Model Analyses." Journal of Hydrometeorology 9, no. 3 (June 1, 2008): 367–87. http://dx.doi.org/10.1175/2007jhm942.1.

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Abstract Proper partitioning of the surface heat fluxes that drive the evolution of the planetary boundary layer in numerical weather prediction models requires an accurate specification of the initial state of the land surface. The National Centers for Environmental Prediction (NCEP) operational Eta Model is used to produce land surface analyses by continuously cycling soil temperature and moisture fields. These fields previously evolved only in response to radiation budget constraints and modeled precipitation, but NCEP recently upgraded the self-cycling process so that soil fields respond instead to the radiation budget and observed precipitation. A comparison of 0000 and 1200 UTC Eta Model analyses of soil temperature and moisture at several soil depths with observations from the Oklahoma Mesonet during 2004 and 2005 shows that there are strong biases in soil temperature and a severe underestimation of soil moisture at all depths. After the change to a new assimilation scheme, there is notable improvement in the magnitude of the analyzed soil moisture fields, although a strong dry bias persists in the soil moisture field. A simple one-layer slab soil model quantifies the effect of such soil moisture errors on the diurnal cycle of soil temperature and reveals that these soil moisture errors alone may account for only 1.6°C increases in predicted maximum soil temperatures during the day and temperature reductions of the same magnitude at night. The much larger remaining soil temperature errors possibly stem from documented problems with the solar radiation and longwave parameterizations within the Eta Model.

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8

Zhang, Xun, Xiaozhen Li, Zhipeng Wen, and Yu Zhao. "Numerical and experimental investigation into the mid- and high-frequency vibration behavior of a concrete box girder bridge induced by high-speed trains." Journal of Vibration and Control 24, no. 23 (March 14, 2018): 5597–609. http://dx.doi.org/10.1177/1077546318761442.

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Concrete box girder bridges exhibit mid- and high-frequency (> 20 Hz) dynamic responses due to train excitations, which result in problems of noise radiation and track deterioration. This study presents a numerical model for box girder vibration prediction. Significant attention is focused on the mid- and high-frequency responses via introduction of a detailed track/bridge subsystem model. A hammer impact test was used to determine the model parameters. The model was then validated using a homologation test. The results show that the wheel/rail force and box girder mobility are the two principal factors that influence box girder vibration spectral characteristics and amplitudes. The box girder responses at cross-sections with similar dynamic characteristics vary little, as they increase moderately with the train speed. The application of a fastening system with low stiffness and high damping can effectively reduce box girder vibration. However, the elastic modulus and damping of the cement–asphalt mortar, and the thickness of the track slab and bearing base exert the smallest influences on the vibrations. The box girder slab thickness should be designed appropriately because its dynamic behavior is closely associated with the slab characteristics.

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9

Liu, Xiao, Nan Zhang, Qikai Sun, Kunpeng Wang, and Zhaozhi Wu. "Parametric Analysis of Structural Noise of Steel-Concrete Composite Slab Beams." Shock and Vibration 2022 (March 7, 2022): 1–10. http://dx.doi.org/10.1155/2022/3176793.

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In this study, the vibration acceleration and radiation structure noise in specific points, 30 cm away from the center surface of each plate of the concrete deck, web, and flange of the steel beam, are measured via the hammering test. The test is conducted on the middle concrete deck of an 8.5 m steel-concrete composite slab beam. The accuracy of the numerical model is then carefully justified. The influence of the number of shear studs, spacing, and arrangement of ribs on the concerning results is methodically examined and discussed by employing the numerical model. In the center frequency of 10–1000 Hz, the total sound power level of the structure can be lessened by improving the concrete deck thickness as well as the number of shear studs. The reduction of the rib spacing can effectively lessen the sound power level as well. The noise reduction of the plate with rib arrangement in the midspan zone is more influential than the case with uniform layout in the whole span.

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10

Li, Yang, and Hao Ling. "NUMERICAL MODELING AND MECHANISM ANALYSIS OF VHF WAVE PROPAGATION IN FORESTED ENVIRONMENTS USING THE EQUIVALENT SLAB MODEL." Progress In Electromagnetics Research 91 (2009): 17–34. http://dx.doi.org/10.2528/pier09012306.

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Menart, J. A., HaeOk Skarda Lee, and Tae-Kuk Kim. "Discrete Ordinates Solutions of Nongray Radiative Transfer With Diffusely Reflecting Walls." Journal of Heat Transfer 115, no. 1 (February 1, 1993): 184–93. http://dx.doi.org/10.1115/1.2910647.

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Nongray gas radiation in a plane parallel slab bounded by gray, diffusely reflecting walls is studied using the discrete ordinates method. The spectral equation of transfer is averaged over a narrow wavenumber interval preserving the spectral correlation effect. The governing equations are derived by considering the history of multiple reflections between two reflecting walls. A closure approximation is applied so that only a finite number of reflections have to be explicitly included. The closure solutions express the physics of the problem to a very high degree and show relatively little error. Numerical solutions are obtained by applying a statistical narrow-band model for gas properties and a discrete ordinates code. The net radiative wall heat fluxes and the radiative source distributions are obtained for different temperature profiles. A zeroth-degree formulation, where no wall reflection is handled explicitly, is sufficient to predict the radiative transfer accurately for most cases considered, when compared with increasingly accurate solutions based on explicitly tracing a larger number of wall reflections without any closure approximation applied.

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12

Urquhart, K. B., and J. F. Cochran. "The effect of nonlocal conductivity on the transmission of microwave radiation through ferromagnetic metals in the field-normal configuration." Canadian Journal of Physics 64, no. 7 (July 1, 1986): 796–821. http://dx.doi.org/10.1139/p86-141.

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Procedures are described for the numerical calculation of the electric-field distributions generated in a model ferromagnetic metal slab of thickness d by incident microwave radiation when a static magnetic field is directed along the slab normal and the mean free path ℓ of the charge carriers becomes comparable to, or greater than, the skin depth δ. The model metal is characterized by a local, frequency-dependent permeability; a spherical Fermi surface; and a nonlocal relationship between the current density and the electric-field distribution. The two limiting cases of specular and diffuse scattering of the charge carriers at the slab faces are considered. Electric-field distributions, transmission amplitudes, and surface impedances have been calculated for a wide range of ℓ and d using parameters that simulate nickel. For diffuse surface scattering, the transmission of the magnetically active mode increases at both ferromagnetic resonance (FMR) and cyclotron resonance (CR). A most striking result is the total absence of structure in the magnetic-field dependence of the transmission amplitude near fields corresponding to FMR or to CR for the case of specular scattering. It is demonstrated that very simple formulae provide a good estimate of the free-space transmission amplitudes for both specular and diffuse surface scattering when [Formula: see text] and d/ℓ ≥ 1.

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13

Platacis, Ernests, Imants Kaldre, Ervins Blumbergs, Linards Goldsteins, and Karlis Gailitis. "Optimization of electroslag melting towards to titanium morphology improvement in combined Kroll process." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 39, no. 1 (December 6, 2019): 3–11. http://dx.doi.org/10.1108/compel-05-2019-0198.

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Purpose The paper aims to optimize calcium difluoride electrical melting process towards creating titanium production with improved morphology by combining titanium reduction and electroslag melting processes. The study aims to explore optimal electrical heating power in the slag supplied via tungsten electrode and formation of a stable skull layer on water-cooled walls of a cylindrical stainless steel reactor, which is crucial for electroslag melting. Design/methodology/approach The multi-physical numerical modelling approach using commercial software COMSOL Multiphysics is presented in the paper by coupling electrical, heat transfer and fluid flow problems. The slag material phase change and corresponding changes of physical properties such as electrical conductivity and viscosity are modelled by step function, sharply changing value of parameter near the phase change temperature. A parametric study of applied electrical power has been carried out to find optimal conditions for the skull-layer formation. Findings The paper provides an estimation of necessary electrical power to avoid overheating or solidification of the top layer of slag, which is unacceptable for the combined Kroll process. The study also revealed important poloidal buoyancy flow with characteristic velocity of few cm/s of in the reactor, which governs the heat transfer process and formation of the skull layer. Research limitations/implications The presented simplification in numerical model offers high calculation speed but lacks fully developed phase change model, e.g. excluding latent heat. Also, heat transfer through radiation is neglected in the model. Originality/value The paper presents an original way to overcome the complexity of modelling slag electrical melting/solidification phenomena using temperature-dependent properties with step functions.

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14

Hertwig, Denise, Sue Grimmond, Margaret A. Hendry, Beth Saunders, Zhengda Wang, Marine Jeoffrion, Pier Luigi Vidale, et al. "Urban signals in high-resolution weather and climate simulations: role of urban land-surface characterisation." Theoretical and Applied Climatology 142, no. 1-2 (August 7, 2020): 701–28. http://dx.doi.org/10.1007/s00704-020-03294-1.

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Abstract Two urban schemes within the Joint UK Land Environment Simulator (JULES) are evaluated offline against multi-year flux observations in the densely built-up city centre of London and in suburban Swindon (UK): (i) the 1-tile slab model, used in climate simulations; (ii) the 2-tile canopy model MORUSES (Met Office–Reading Urban Surface Exchange Scheme), used for numerical weather prediction over the UK. Offline, both models perform better at the suburban site, where differences between the urban schemes are less pronounced due to larger vegetation fractions. At both sites, the outgoing short- and longwave radiation is more accurately represented than the turbulent heat fluxes. The seasonal variations of model skill are large in London, where the sensible heat flux in autumn and winter is strongly under-predicted if the large city centre magnitudes of anthropogenic heat emissions are not represented. The delayed timing of the sensible heat flux in the 1-tile model in London results in large negative bias in the morning. The partitioning of the urban surface into canyon and roof in MORUSES improves this as the roof tile is modelled with a very low thermal inertia, but phase and amplitude of the grid box-averaged flux critically depend on accurate knowledge of the plan-area fractions of streets and buildings. Not representing non-urban land cover (e.g. vegetation, inland water) in London results in severely under-predicted latent heat fluxes. Control runs demonstrate that the skill of both models can be greatly improved by providing accurate land cover and morphology information and using representative anthropogenic heat emissions, which is essential if the model output is intended to inform integrated urban services.

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15

Clarisse, J. M., J. L. Pfister, S. Gauthier, and C. Boudesocque-Dubois. "A hydrodynamic analysis of self-similar radiative ablation flows." Journal of Fluid Mechanics 848 (June 5, 2018): 219–55. http://dx.doi.org/10.1017/jfm.2018.343.

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Self-similar solutions to the compressible Euler equations with nonlinear conduction are considered as particular instances of unsteady radiative deflagration – or ‘ablation’ – waves with the goal of characterizing the actual hydrodynamic properties that such flows may present. The chosen family of solutions, corresponding to the ablation of an initially quiescent perfectly cold and homogeneous semi-infinite slab of inviscid compressible gas under the action of increasing external pressures and radiation fluxes, is well suited to the description of the early ablation of a target by gas-filled cavity X-rays in experiments of high energy density physics. These solutions are presently computed by means of a highly accurate numerical method for the radiative conduction model of a fully ionized plasma under the approximation of a non-isothermal leading shock wave. The resulting set of solutions is unique for its high fidelity description of the flows down to their finest scales and its extensive exploration of external pressure and radiative flux ranges. Two different dimensionless formulations of the equations of motion are put forth, yielding two classifications of these solutions which are used for carrying out a quantitative hydrodynamic analysis of the corresponding flows. Based on the main flow characteristic lengths and on standard characteristic numbers (Mach, Péclet, stratification and Froude numbers), this analysis points out the compressibility and inhomogeneity of the present ablative waves. This compressibility is further analysed to be too high, whether in terms of flow speed or stratification, for the low Mach number approximation, often used in hydrodynamic stability analyses of ablation fronts in inertial confinement fusion (ICF), to be relevant for describing these waves, and more specifically those with fast expansions which are of interest in ICF. Temperature stratification is also shown to induce, through the nonlinear conductivity, supersonic upstream propagation of heat-flux waves, besides a modified propagation of quasi-isothermal acoustic waves, in the flow conduction regions. This description significantly departs from the commonly admitted depiction of a quasi-isothermal conduction region where wave propagation is exclusively ascribed to isothermal acoustics and temperature fluctuations are only diffused.

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Savajano, Romain, Daniel F. Potter, Ojas Joshi, and Pénélope Leyland. "Radiation Analysis for Two Trajectory Points of the Fire II Entry." International Journal of Aerospace Engineering 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/597930.

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Numerical rebuilding of two trajectory points (t=1634 s andt=1643 s) of the Fire II mission has been carried out to predict the radiative heat flux for nonequilibrium and close-to-equilibrium conditions. The simulations have been performed with eilmer3 in an uncoupled way and using a tangent slab method for the radiation transport. Different population models (QSS and Boltzmann) have been compared, and the influence of catalytic wall condition was taken into account. An analysis on the spectral range and on the spectral resolution has also been carried out.

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17

Rywotycki, M., Z. Malinowski, K. Miłkowska-Piszczek, A. Gołdasz, and B. Hadała. "Comparison of Four Models of Radiative Heat Transfer Between Flat Surface to Evaluate the Temperature Field Based on Example of the Continuous Casting Mould." Archives of Metallurgy and Materials 60, no. 1 (April 1, 2015): 209–13. http://dx.doi.org/10.1515/amm-2015-0033.

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AbstractThe paper presents the results of research concerning the influence of radiative heat transfer on the strand and mould interface. The four models for determining the heat transfer boundary conditions within the primary cooling zone for the continuous casting process of steel have been presented. A cast slab - with dimensions of 1280×220 mm - has been analysed. Models describing the heat transfer by radiation have been specified and applied in the numerical calculations. The problem has been solved by applying the finite element method and the self-developed software. The simulation results, along with their analysis, have been presented. The developed models have been verified based on the data obtained from the measurements at the industrial facility.

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18

Jahangir, Irsa, Hafiz Naeem, Abdul Faheem, and Anjum Tauqir. "Investigation of Cracks on Internal Surfaces of Extruded Cold Worked Thick Walled Pipes of an Age Hardened Al-Alloy." Defect and Diffusion Forum 418 (August 19, 2022): 137–43. http://dx.doi.org/10.4028/p-npjg01.

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Thick seamless pipes of hardenable aluminum alloys demand close geometrical tolerances as well as high quality surface finish which are met by cold drawing after a series of different thermo-mechanical treatments. To meet the requirements of critical applications the final product undergoes stringent quality inspection procedures. State of the art quality assessment can detect even minor isolated defects. The production facilities develop their quality criteria suitable for specific applications. The present study investigated minute defects on the inside surface of thick seamless pipes, proposed mechanism of their formation and suggested the impact of defects on the end use. The root cause analysis was conducted, and measures were suggested to control the defects. Thick extruded seamless aluminum alloy pipes underwent a series of different thermo mechanical treatments; the final dimensions with required tolerances and the surface finish were achieved by adopting a 2-step cold drawing process. Cold drawing generated residual stresses which resulted in the formation of cracks in the material, preferentially at the defects generated during solidification and/or extrusion processes. The final product underwent stringent quality inspection, and the material was rejected if cracks of size 3 mm or larger were detected. The die scratches or notches generated on the inside surface of the pipes, during extrusion are assumed to grow if subjected to high stresses during subsequent processes, e.g. cold working. Observations at high magnification in SEM helped to determine the morphology of cracks. Radiographic testing did not detect any crack in the bulk material. Particles with faceted features indicated the presence of inclusion. Inclusions were detected in the form of strings along the direction of cold drawing. Energy dispersive spectrometry in SEM was used to determine the composition of inclusion detected in the vicinity of cracks. Almost all the inclusions were rich in silicon, iron, calcium along with carbon; it indicated that the inclusions were trapped particles of fluxes, slag, and brick powder. Particles rich in Ca, Na and/or Cl indicated entrapped flux, Fe and Si were mostly coming from aluminum scrap and refractory powder while presence of carbon indicated entrapped extrusion lubricant. Inclusions rich in a large variety of unwanted elements indicated presence of slag particles. Numerical analysis was conducted to develop a model in FEM in which scratches of different depths were introduced and autofrettage pressure was applied to determine the stresses generated according to the established Von Mises Model; the latter was used to establish the yield criteria. Finite Element Modelling concluded that when cold drawing pressure was applied on a pipe with a single notch of depth 0.3mm or three notches of depth 0.1 or greater at different locations the Von Mises stresses approached the yield strength of the pipe.

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Neno, Rodrigo J. F., Beatriz S. Dias, Jorge E. P. Navalho, and José C. F. Pereira. "Numerical Simulation of Heat Removal from a Window Slab Partition of a Radiative Coil Coating Oven." Energies 15, no. 6 (March 12, 2022): 2080. http://dx.doi.org/10.3390/en15062080.

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In this work, fluid flow and heat transfer performance of a radiative coil coating oven is numerically investigated. In the coil coating oven concept under consideration, porous radiant burners provide the required energy to evaporate the volatile species (solvents) from the applied coating and to promote curing reactions. To avoid the mixing between burners flue gas (with a non-negligible oxygen content) and evaporated (combustible) solvents in the oven (which could lead to a catastrophic oven failure), a semi-transparent window in between both atmospheres is applied. To ensure the window thermal stability during the oven operation, window cooling by wall jets is considered. Different turbulence models were compared against available wall jet heat transfer correlations to select the most suitable for three-dimensional (3D) numerical simulations. Convective heat transfer correlations purposefully developed were embedded in a one-dimensional (1D) window energy model for fast performance characterization, analysing the most influencing parameters—window radiative properties, thickness, inlet temperature and velocity of wall jets, and cooling strategy. The 1D window thermal performance is compared with literature and 3D results considering the full coil coating oven, providing satisfactory confidence on the developed strategy. The 1D model is used for an optimisation study to find the minimum energy consumption while ensuring the safety requirements (maximum window temperature and thermal gradient) are met.

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Díaz, F., G. Montero, J. M. Escobar, E. Rodríguez, and R. Montenegro. "An adaptive solar radiation numerical model." Journal of Computational and Applied Mathematics 236, no. 18 (December 2012): 4611–22. http://dx.doi.org/10.1016/j.cam.2012.04.018.

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Vaytet, N. M. H., E. Audit, B. Dubroca, and F. Delahaye. "A numerical model for multigroup radiation hydrodynamics." Journal of Quantitative Spectroscopy and Radiative Transfer 112, no. 8 (May 2011): 1323–35. http://dx.doi.org/10.1016/j.jqsrt.2011.01.027.

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Díaz, F., G. Montero, J. M. Escobar, E. Rodríguez, and R. Montenegro. "A new predictive solar radiation numerical model." Applied Mathematics and Computation 267 (September 2015): 596–603. http://dx.doi.org/10.1016/j.amc.2015.01.036.

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Andrieu, François, Frédéric Schmidt, Bernard Schmitt, Sylvain Douté, and Olivier Brissaud. "Retrieving the characteristics of slab ice covering snow by remote sensing." Cryosphere 10, no. 5 (September 15, 2016): 2113–28. http://dx.doi.org/10.5194/tc-10-2113-2016.

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Abstract. We present an effort to validate a previously developed radiative transfer model, and an innovative Bayesian inversion method designed to retrieve the properties of slab-ice-covered surfaces. This retrieval method is adapted to satellite data, and is able to provide uncertainties on the results of the inversions. We focused on surfaces composed of a pure slab of water ice covering an optically thick layer of snow in this study. We sought to retrieve the roughness of the ice–air interface, the thickness of the slab layer and the mean grain diameter of the underlying snow. Numerical validations have been conducted on the method, and showed that if the thickness of the slab layer is above 5 mm and the noise on the signal is above 3 %, then it is not possible to invert the grain diameter of the snow. In contrast, the roughness and the thickness of the slab can be determined, even with high levels of noise up to 20 %. Experimental validations have been conducted on spectra collected from laboratory samples of water ice on snow using a spectro-radiogoniometer. The results are in agreement with the numerical validations, and show that a grain diameter can be correctly retrieved for low slab thicknesses, but not for bigger ones, and that the roughness and thickness are correctly inverted in every case.

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Derishev, E. V. "Numerical Model of Synchrotron-Self-Compton Radiation Sources." Izvestiya vysshikh uchebnykh zavedenii. Radiofizika 63, no. 11 (2020): 958–72. http://dx.doi.org/10.52452/00213462_2020_63_11_958.

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Derishev, E. V. "Numerical Model of Synchrotron-Self-Compton Radiation Sources." Radiophysics and Quantum Electronics 63, no. 11 (April 2021): 862–75. http://dx.doi.org/10.1007/s11141-021-10100-z.

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Meyer, W. D., and G. V. Rao. "Radiation Fog Prediction Using a Simple Numerical Model." Pure and Applied Geophysics 155, no. 1 (June 1, 1999): 57–80. http://dx.doi.org/10.1007/s000240050254.

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Wu, Di, Gangqiang Kong, Hanlong Liu, Xi Zhu, and Hefu Pu. "Performance of a bridge deck as solar collector in a thermal energy storage system." E3S Web of Conferences 205 (2020): 07009. http://dx.doi.org/10.1051/e3sconf/202020507009.

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Solar energy can be stored in subsurface and extracted to melt snow and deice in winter. In summer, the bridge deck heat element in a bridge deicing system could serve as a solar energy collector without additional cost. Numerical models were developed in this study to investigate the performance of a bridge deck solar collector. The effects of radiation intensity and wind speed on the solar energy collection efficiency of a bridge deck solar energy collector were discussed and analyzed. The results show that the temperature of the slab was decreased during the solar collection process, and the solar energy collection efficiency of the bridge deck solar collector was about 26~47%. The collection efficiency of solar energy at a given wind speed was increased with the decreasing of the radiation energy, and this effect was more pronounced when the wind speed was higher. The solar energy collection was beneficial to the durability of the top asphalt layer as well as the structural response of the bridge because the magnitude and gradient of the slab temperature were much lower when the bridge deck served as a solar energy collector.

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Bergot, Thierry, and Daniel Guedalia. "Numerical Forecasting of Radiation Fog. Part I: Numerical Model and Sensitivity Tests." Monthly Weather Review 122, no. 6 (June 1994): 1218–30. http://dx.doi.org/10.1175/1520-0493(1994)122<1218:nforfp>2.0.co;2.

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Selamet, Serdar, and Caner Bolukbas. "Fire performance of single plate shear connections in a composite floor." Journal of Structural Fire Engineering 7, no. 4 (December 12, 2016): 316–27. http://dx.doi.org/10.1108/jsfe-12-2016-022.

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Purpose This paper aims to present a numerical investigation on the fire performance of a single plate shear connection in a steel-framed composite floor. Large-scale fire experiments show that the tensile membrane action of the concrete slab enhances the fire performance of composite floors. The enhancement in the performance is contributed to large slab deflections. However, these deflections cause significant rotations and tensile force in the single plate connection. Design/methodology/approach A finite element model is constructed, which consists of a secondary steel beam, concrete slab and shear connection components. The interaction between the connection components such as bolts and single plate is defined by contact surfaces. The analysis is conducted in two uncoupled phases: thermal analysis by creating fire boundaries on the composite floor model with convective and radiative heat transfer, and mechanical analysis by considering thermal expansion and changes in the material stiffness and strength due to temperature. Findings The thermo-mechanical analysis of the composite floor finite element model shows that the structure survives the 2-h Standard fire, but the connection fails by bolt shear and buckling of the connection plate. Originality/value This paper investigates the fire performance of a shear connection in a steel-framed concrete slab. Previous work generally focused on the concrete slab behavior only. The originality of the research is that the connection is considered as part of a sub-assembly and is subjected to forces due to concrete and steel beam interaction.

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Szuchta, Maciej, and Jakub Ośko. "Numerical model of thyroid counter." Nukleonika 61, no. 1 (March 1, 2016): 45–47. http://dx.doi.org/10.1515/nuka-2016-0010.

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Abstract The aim of this study was to develop a numerical model of spectrometric thyroid counter, which is used for the measurements of internal contamination by in vivo method. The modeled detector is used for a routine internal exposure monitoring procedure in the Radiation Protection Measurements Laboratory of National Centre for Nuclear Research (NCBJ). This procedure may also be used for monitoring of occupationally exposed nuclear medicine personnel. The developed model was prepared using Monte Carlo code FLUKA 2011 ver. 2b.6 Apr-14 and FLAIR ver. 1.2-5 interface. It contains a scintillation NaI(Tl) detector, the collimator and the thyroid water phantom with a reference source of iodine 131I. The geometry of the model was designed and a gamma energy spectrum of iodine 131I deposited in the detector was calculated.

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31

Mościbrodzka, M. "Linear and circular polarization of a 1D relativistic jet model." Astronomy & Astrophysics 623 (March 2019): A152. http://dx.doi.org/10.1051/0004-6361/201834503.

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Context. Polarimetric observations of black holes allow us to probe structures of magnetic fields and plasmas in strong gravity. Aims. We present a study of the polarimetric properties of a synchrotron spectrum emitted from a relativistic jet using a low-dimensional model. Methods. A novel numerical scheme is used to integrate relativistic polarized radiative transfer equations in a slab geometry where the plasma conditions change along the integration path. Results. We find that the simple model of a non-uniform jet can recover basic observational characteristics of some astrophysical sources with a relativistic jet, such as extremely high rotation measures. Our models incorporate a time-dependent component. A small fluctuation in density or temperature of the plasma along the jet produces significant amounts of fluctuations not only in the fractional linear and circular polarizations, but also in the jet internal rotation measures. Conclusions. The low-dimensional models presented here are developed within the same computational framework as the complex three-dimensional general relativistic magnetohydrodynamics simulations of black hole disks and jets, and they offer guidance when interpreting the results from more complex polarization models. The models presented here are scalable to stationary and transient polarized radio emissions produced by relativistic plasma ejected from around compact objects, in both stellar-mass and supermassive black hole systems.

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32

Ping, Yang, and Cai Qiming. "Numerical Model For Transferring Of Solar Radiation In Taihu Lake." Journal of Lake Sciences 2, no. 2 (1990): 1–8. http://dx.doi.org/10.18307/1990.0201.

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Guo, Peng-hua, Jing-yin Li, and Yuan Wang. "Numerical simulations of solar chimney power plant with radiation model." Renewable Energy 62 (February 2014): 24–30. http://dx.doi.org/10.1016/j.renene.2013.06.039.

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34

Errera, Marc-Paul, Rocco Moretti, Julien Mayeur, Matteo Gelain, Lionel Tessé, Jean-Michel Lamet, and Emmanuel Laroche. "A numerical predictive model for conjugate heat transfer with radiation." International Journal of Heat and Mass Transfer 160 (October 2020): 120155. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2020.120155.

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35

Karabourniotis, D., and J. van der Mullen. "Numerical validation of a self-absorption model for plasma radiation." Journal of Physics D: Applied Physics 38, no. 17 (August 19, 2005): 3016–27. http://dx.doi.org/10.1088/0022-3727/38/17/s02.

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36

Waqas, M., M. Ijaz Khan, T. Hayat, and A. Alsaedi. "Numerical simulation for magneto Carreau nanofluid model with thermal radiation: A revised model." Computer Methods in Applied Mechanics and Engineering 324 (September 2017): 640–53. http://dx.doi.org/10.1016/j.cma.2017.06.012.

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37

Motoyama, K., T. Umemoto, and H. Shang. "Radiation driven implosion model for star formations near an H II region." Proceedings of the International Astronomical Union 2, S237 (August 2006): 450. http://dx.doi.org/10.1017/s1743921307002384.

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AbstractWe performed numerical simulation including UV radiation transfer, and investigated effects of radiation driven implosion on star formation processes. We also observed two bright-rimmed clouds with C12O(J=1-0) and C13O(J=1-0) in order to compare density distributions between numerical results and observational results. Density profiles of bright-rimmed clouds are consistent with those of numerical simulations. These facts insist that star formations in bright-rimmed clouds are triggered by radiation driven implosion.

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38

Nguyen, Bao The, Viet Van Hoang, and Hiep Chi Le. "Model to generate solar radiation values for solar distillation numerical simulations." DESALINATION AND WATER TREATMENT 222 (2021): 47–59. http://dx.doi.org/10.5004/dwt.2021.27117.

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39

Hanson, Joshua, Biliana Paskaleva, Eric Keiter, Pavel Bochev, and Charles Hembree. "A Hybrid Analytic-Numerical Compact Model for Radiation Induced Photocurrent Effects." IEEE Transactions on Nuclear Science 69, no. 2 (February 2022): 160–68. http://dx.doi.org/10.1109/tns.2022.3144069.

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Jankowski-Mihułowicz, Piotr, Wojciech Lichoń, and Mariusz Węglarski. "Numerical Model of Directional Radiation Pattern Based on Primary Antenna Parameters." International Journal of Electronics and Telecommunications 61, no. 2 (June 1, 2015): 191–97. http://dx.doi.org/10.1515/eletel-2015-0025.

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Abstract The new numerical model of directional radiation pattern, in which part of energy is emitted in side and back lobs, has been presented in this paper. The model input values are determined on the base of primary parameters that can be read from the datasheet of used antennas. The special software tool NmAntPat has been elaborated to carry out the described task. The elaborated model, program and output files can be easily implemented into an analysis of radio wave propagation phenomenon in any algorithms and numerical calculations. The comparison of the graphical plots that have been obtained on the base of measurements, producers’ data specification notes and modelling results confirms the model correctness.

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Gauthier, Robert C. "Ray optics model and numerical computations for the radiation pressure micromotor." Applied Physics Letters 67, no. 16 (October 16, 1995): 2269–71. http://dx.doi.org/10.1063/1.115122.

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Bott, Andreas, and Gregory R. Carmichael. "Multiphase chemistry in a microphysical radiation fog model—A numerical study." Atmospheric Environment. Part A. General Topics 27, no. 4 (March 1993): 503–22. http://dx.doi.org/10.1016/0960-1686(93)90208-g.

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43

Bae, Soo Hwan, Jin Hyun Nam, Chi Sung Song, and Charn-Jung Kim. "A Numerical Model for Freeze Drying Processes with Infrared Radiation Heating." Numerical Heat Transfer, Part A: Applications 58, no. 5 (August 27, 2010): 333–55. http://dx.doi.org/10.1080/10407782.2010.508437.

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44

Yao, Jianda, and Weicheng Fan. "Theory and numerical study on three dimensional discrete transfer radiation model." Journal of Thermal Science 3, no. 4 (December 1994): 263–66. http://dx.doi.org/10.1007/bf02653137.

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45

DeSouza-Machado, Sergio, L. Larrabee Strow, Andrew Tangborn, Xianglei Huang, Xiuhong Chen, Xu Liu, Wan Wu, and Qiguang Yang. "Single-footprint retrievals for AIRS using a fast TwoSlab cloud-representation model and the SARTA all-sky infrared radiative transfer algorithm." Atmospheric Measurement Techniques 11, no. 1 (January 25, 2018): 529–50. http://dx.doi.org/10.5194/amt-11-529-2018.

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Abstract. One-dimensional variational retrievals of temperature and moisture fields from hyperspectral infrared (IR) satellite sounders use cloud-cleared radiances (CCRs) as their observation. These derived observations allow the use of clear-sky-only radiative transfer in the inversion for geophysical variables but at reduced spatial resolution compared to the native sounder observations. Cloud clearing can introduce various errors, although scenes with large errors can be identified and ignored. Information content studies show that, when using multilayer cloud liquid and ice profiles in infrared hyperspectral radiative transfer codes, there are typically only 2–4 degrees of freedom (DOFs) of cloud signal. This implies a simplified cloud representation is sufficient for some applications which need accurate radiative transfer. Here we describe a single-footprint retrieval approach for clear and cloudy conditions, which uses the thermodynamic and cloud fields from numerical weather prediction (NWP) models as a first guess, together with a simple cloud-representation model coupled to a fast scattering radiative transfer algorithm (RTA). The NWP model thermodynamic and cloud profiles are first co-located to the observations, after which the N-level cloud profiles are converted to two slab clouds (TwoSlab; typically one for ice and one for water clouds). From these, one run of our fast cloud-representation model allows an improvement of the a priori cloud state by comparing the observed and model-simulated radiances in the thermal window channels. The retrieval yield is over 90 %, while the degrees of freedom correlate with the observed window channel brightness temperature (BT) which itself depends on the cloud optical depth. The cloud-representation and scattering package is benchmarked against radiances computed using a maximum random overlap (RMO) cloud scheme. All-sky infrared radiances measured by NASA's Atmospheric Infrared Sounder (AIRS) and NWP thermodynamic and cloud profiles from the European Centre for Medium-Range Weather Forecasts (ECMWF) forecast model are used in this paper.

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46

Asensio, M. I., and L. Ferragut. "On a wildland fire model with radiation." International Journal for Numerical Methods in Engineering 54, no. 1 (2002): 137–57. http://dx.doi.org/10.1002/nme.420.

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47

Crnomarkovic, Nenad, Miroslav Sijercic, Srdjan Belosevic, Dragan Tucakovic, and Titoslav Zivanovic. "Influence of application of Hottel’s zonal model and six-flux model of thermal radiation on numerical simulations results of pulverized coal fired furnace." Thermal Science 16, no. 1 (2012): 271–82. http://dx.doi.org/10.2298/tsci110627126c.

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Difference of results of numerical simulation of pulverized coal fired furnace when mathematical models contain various radiation models has been described in paper. Two sets of numerical simulations of pulverized coal fired furnace of 210 MWe power boiler have been performed. One numerical simulation has contained Hottel?s zonal model, whereas the other numerical simulation has contained six-flux model. Other details of numerical simulations have been identical. The influence of radiation models has been examined through comparison of selected variables (gas-phase temperature, oxygen concentration, and absorbed radiative heat rate of surface zones of rear and right furnace walls), selected global parameters of furnace operation (total absorbed heat rate by all furnace walls and furnace exit gas-phase temperature). Computation time has been compared as well. Spatially distributed variables have been compared through maximal local differences and mean differences. Maximal local difference of gas-phase temperature has been 8.44%. Maximal local difference of absorbed radiative heat rate of the surface zones has been almost 80.0%. Difference of global parameters of furnace operation has been expressed in percents of value obtained by mathematical model containing Hottel?s zonal model and has not been bigger than 7.0%. Computation time for calculation of 1000 iterations has been approximately the same. Comparison with other radiation models is necessary for assessment of differences.

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Xie, Hang Sheng. "The Establishment and Analysis of the Radiation Noise Model of the Ventilator Enclosure." Applied Mechanics and Materials 533 (February 2014): 52–59. http://dx.doi.org/10.4028/www.scientific.net/amm.533.52.

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The radiation noise of the ventilator enclosure is mainly caused by the vibration of the enclosure. It is not easy to calculate and measure. By analyzing the reasons for the radiation noise of the ventilator enclosure, this paper establishes the noise model, uses a series of numerical processing techniques, and overcomes the past complexity and diversity of the numerical solution. By means of the model verification, the comparison between the numerical solution and the measured value shows that this method can be used to calculate some complex noise power.

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Adamiec, Grzegorz, Andrzej Bluszcz, Richard Bailey, and Marta Garcia-Talavera. "Finding model parameters: Genetic algorithms and the numerical modelling of quartz luminescence." Radiation Measurements 41, no. 7-8 (August 2006): 897–902. http://dx.doi.org/10.1016/j.radmeas.2006.05.005.

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Adamiec, Grzegorz. "Investigation of a numerical model of the pre-dose mechanism in quartz." Radiation Measurements 39, no. 2 (February 2005): 175–89. http://dx.doi.org/10.1016/j.radmeas.2004.03.008.

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