Emissivity Values Research Articles

Numerical Investigation on Forced Hybrid Nanofluid Flow and Heat Transfer Inside a Three-Dimensional Annulus Equipped with Hot and Cold Rods: Using Symmetry Simulation

A 3D computational fluid dynamics method is used in the current study to investigate the hybrid nanofluid (HNF) flow and heat transfer in an annulus with hot and cold rods. The chief goal of the current study is to examine the influences of dissimilar Reynolds numbers, emissivity coefficients, and dissimilar volume fractions of nanoparticles on hydraulic and thermal characteristics of the studied annulus. In this way, the geometry is modeled using a symmetry scheme. The heat transfer fluid is a water, ethylene–glycol, or water/ethylene–glycol mixture-based Cu-Al2O3 HNF, which is a Newtonian NF. According to the findings for the model at Re = 3000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. ϕ1 and ϕ2 are the volume concentration of Al2O3 and Cu nanoparticles, respectively. For all studied cases, the total average Nusselt number (Nuave) reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 or 0.02 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. Additionally, for the case with water as the base fluid, the total Nuave at ϕ2 = 0.05 is higher than the values at ϕ2 = 0.00. On the other hand, for the other cases, the total Nuave at ϕ2 = 0.05 is lower than the values at ϕ2 = 0.00. For all studied cases, the case with water as the base fluid has the maximum Nuave. Plus, for the model at Re = 4000 and ϕ1 = 0.05, all studied cases with different base fluids have similar behavior. For all studied cases, the total Nuave reduces firstly by an increment of the volume concentrations of Cu nanoparticles until ϕ2 = 0.01 and then, the total Nuave rises by an increment of the volume concentrations of Cu nanoparticles. The Nuave augments are found by an increment of Reynolds numbers. Higher emissivity values should lead to higher radiation heat transfer, but the portion of radiative heat transfer in the studied annulus is low and therefore, has no observable increment in HNF flow and heat transfer.

Emissivity of spinel and titanate structures aiming at the development of industrial high-temperature ceramic coatings

High-emissivity coatings have been pointed out as a promising energy-saving solution for industrial furnaces since their development in the aerospace area. However, due to a lack of in-depth knowledge of radiation heat transfer and thermal-optical interactions, as well as the struggle to obtain proper emissivity values, commercial versions of such coatings have not yet been widely established. In this work, the evaluation of some fundamentals on thermal-optical properties, and their potential applications, led to the development of engineered structures of usual inexpensive oxides, such as the titanate and spinel ones, which presented improved emissivity values, even at high temperatures (1500 °C), when compared to commercial references. The findings of these compounds indicated a considerable cost-effective saving potential for large industrial furnaces.

Passive performance enhancement of parabolic trough solar concentrators using internal radiation heat shields

Boosting the optical and thermal efficiencies of parabolic trough concentrators is gaining renewal global interest for improving the overall concentrating solar power plant efficiency and reducing the specific costs of power generation. Using internal radiation heat shields in the annular space of the heat collection element is an attractive passive solution that is not well-addressed in the literature. This study is a first attempt to analyze and map both energetic and exergetic performances of parabolic trough concentrators in terms of the configuration of the radiation heat shield and the operating conditions of the concentrator. A 3D model based on Monte-Carlo ray tracing and computational fluid dynamics is developed, validated, and used to examine 420 combinations of design and operating parameters. The proposed design outperformed the conventional one in the whole spectrum of operating conditions, except for a narrow range of low operating temperatures and high flow rates. Floating radiation heat shields with small diameters and large shading angles enhanced the temperature uniformity of heat collection element and showed the highest enhancement ratios of both energy and exergy efficiencies, which were up to 15.4 and 14.4%, respectively. A radiation heat shield with a diameter of 75 mm and a shading angle of 150° was found the best performing configuration for most operating conditions. Increasing the shield’s emissivity (0.06) to that of the absorber tube (0.14) reduced the energy and exergy efficiencies by up to 33.75 and 29.06%, respectively. The effectiveness of the modified design was more pronounced at lower solar irradiance levels. The enhancements of energy and exergy efficiency decreased by 85.76 and 86.40% as the irradiance increased from 200 to 1000 W/m2. However, the modified design was still more efficient at all considered values of emissivity and solar irradiance.

Assessment of numerical radiation models on the heat transfer of an aero-engine combustion chamber

Thermal radiation is the most dominant type of heat transfer inside the combustion chamber, which can directly affect the temperature distributions at the combustor walls. This paper provides a comprehensive analysis of the effects of two radiation models on the flame and liner-walls temperatures. A combustion chamber used in the Rolls-Royce-RB-183 turbofan engine was examined in this study by integrating a solid combustor model with the numerical fluid domain. The results indicated that the implementation of radiation models shrinks the flame peak-temperature and altered temperature distribution across the liner. The Discrete Ordinates Method (DOM) estimated a 10% higher temperature at the front part of the liner compared to the non-radiation model and 15% less than the P-1 radiation method. After the dilution zone, the DOM and P-1 models estimated respectively 15% and 25% reduction in the liner temperature compared to the non-radiation combustor. The radiation models have also down predicted the flame temperature by 200 K and more than 200 K for DOM and P-1 case respectively. The results also showed that the emissivity value had minimal effects on the combustor temperature distribution. The DOM considered being more accurate to estimate the combustor wall and flow temperatures compared to the P-1 radiation method.

Comparison of emissivity retrieval methods from ASTER data using Fourier-Transform Infrared Spectroscopy

Land surface emissivity retrieval is important for the remote identification of natural materials and can be used to identify the presence of silicate minerals. However, its estimation from passive sensors involves an undetermined function related to radiance data, which is influenced by the atmosphere. We tested three methods for temperature emissivity retrieval in a dune field composed of 99.53% quartz (SiO2) using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. The tested methods were the reference channel method (RCM), emissivity normalization method (ENM), and temperature emissivity separation (TES) method. An average quartz reference spectrum for the dune samples was calculated from an emissivity database based on temperature and used to evaluate the emissivity products of four ASTER images. In general, the three tested methods had a good approximation when analysed the emissivity reference curve, especially for longer wavelengths that ranged between 2 and 4% of emissivity. The RCM and ENM produced very similar results with the coefficients of determination (R2) as 0.9960 (RMSE 0.0184) and 0.9959 (RMSE 0.0185), respectively. RCM method presented superior results (R2: 0.9960, RMSE: 0.0184), compared to the TES method (R2: 0.9947, RMSE: 0.0197). The TES method showed good results only for shorter wavelengths and, hence, to identify specific targets using ASTER data, such as silicate minerals, it is better to use the RCM method. The emissivity value selected at the saturation point of the spectral library based on temperature is fundamental in acquiring more reliable data.

High-temperature solar-selective coatings based on Cr(Al)N. Part 2: Design, spectral properties and thermal stability of multilayer stacks

Two multilayer solar selective absorber coatings [Al/CrN0.95/Cr0.96Al0.04N1.08/Cr0.53Al0.47N1.12/Al2O3 (stack #1) and Cr0.96Al0.04N0.89/Cr0.62Al0.38N1.00/Cr0.53Al0.47N1.12/Al2O3 (stack #2)] were deposited on 316L steel by combining direct current (DC) and high power impulse magnetron sputtering (HiPIMS) technologies with the aim of increasing the working limit temperature. The composition and thickness of the constituent layers were optimized using CODE software to achieve a high solar absorptance (α) and low values of thermal emittance (ε) in the infrared region. The deposited multilayered stacks were heated during 2 h in air at 600, 700 and 800 °C to study their thermal stability and optical performance. Compositional, structural and optical characterization of the stacks (as-prepared and after thermal treatment) was performed. Both stacks presented a good solar selectivity with α > 95% and ε < 15%, were stable up to 600 °C and fulfilled the performance criterion PC < 5% after 600 and 700 °C treatments. Despite the stacks suffered chemical transformations above 600 °C, partial oxidation (stack #1) and Cr2N formation (stack #1 and #2), the optical properties were optimum up to 700 °C for stack #1 (α = 94%, ε(25 °C) = 12%) and 600 °C for stack #2 (α = 93%, ε(25 °C) = 13%). The solar-to-mechanical energy conversion efficiencies (η) of the as-deposited and annealed (600 and 700 °C) samples were up to 20% points higher than the absorber paint commercially used (Pyromark). At 800 °C, they underwent a further structural transformation, provoked by the oxidation of the inner layers, and they consequently lost their solar selectivity.

Land Surface Temperature Estimation After A Decade of Aceh Tsunami (Case Study of West Aceh District of 2013 Data)

Thermal images of Landsat satellite can be utilized by estimating the land surface temperature. Moreover, retrieving the temperature estimation before the current event can be done using temporal analysis. Land surface temperature estimation requires Land Surface Emissivity (LSE) value through the Normalized Difference Vegetation Index (NDVI) approach. The result showed that the average land surface temperature in West Aceh District in 2013 was 26.07 °C. The result also showed that the spatial distribution of temperature spread accordingly following the transect pattern. The temperature in the coastal areas was higher than the hinterland. This phenomenon is due to high built-up in the coastal regions, whereby vegetation is dominant in the hinterland areas.

Ultrahigh emissivity of grating-patterned PDMS film from 8 to 13 μ m wavelength regime

Polydimethylsiloxane (PDMS) is a prominent material for radiative cooling due to its promising optical properties in the mid-infrared spectral region as well as its fabrication easiness. Even though several works have reported that the mid-infrared emissivity of a PDMS film can be increased by surface modification, there is still room for further enhancement through global optimization. Here, we designed and fabricated the thin PDMS film patterned with two-dimensional gratings to obtain the highest emissivity in the wavelength range from 8 to 13 μm. A surrogate-model-based optimization was performed, and the optimum structure exhibited the averaged emissivity value of 0.99 in the wavelength of 8–13 μm, which is the highest value reported to date among polymer-based radiative coolers. For real-world applications, we also developed the fabrication method that is repeatable and applicable for various surfaces using a flexible master mold.

Nusselt number and friction factor variations in a capsule heat exchanger filled with eco‐friendly jatropha seed oil–based multi walled carbon nanotubes nanofluid

The present 3‐D numerical paper investigates Nusselt number and friction factor variations in a capsule heat exchanger filled with eco‐friendly jatropha seed oil–based MWCNTs nanofluid. For all studied models, inlet nanofluid temperature is Tin = 310 K, and the hot source with q = 650 W/m2 is adopted. Due to achieve the most efficient Newtonian nanofluid in present study, solid nanoparticles of MWCNT are added to the base fluid in volume concentration of 0.2% to 0.8%. Also, different riser heights (25, 35, and 50 cm) and different emissivity values of capsule walls (ε = 0.3 and 0.7) are studied in this paper. In the current modeling, the SST k – ω turbulence model has been assumed as the turbulence model. Based on achieved results in this paper, the model with capsule angle of β = 30° has better heat transfer than the other studied slopes, which is followed with models with β = 60° and β = 90°, respectively. Also, it is seen that gravity has a significant influence on velocity contours, and in model with β = 90° more pressure drop may be seen, which is followed with models with β = 60° and β = 90°, respectively. Moreover the predicted pressure drop values from inlet to outlet always increase by increase of Reynolds numbers; therefore, there is an optimum Reynolds number during the studied range of flow velocities which leads to the minimum pressure drop penalty. Also, it is realized that usage of nanofluid at higher nanoparticles volume concentrations leads to higher Nusselt numbers during all studied Reynolds numbers. The model with nanoparticles volume fraction of ϕ = 0.8% has the highest values of predicted average Nusselt number which is followed with the models with ϕ = 0.6%, ϕ = 0.4%, and ϕ = 0.2%, respectively. Besides, it is clearly found that usage of walls with different emissivity values has not a significant influence on thermal–hydraulic characteristics of studied capsule heat exchanger.

Influence of Fe2O3 on the structure and near-infrared emissivity of aluminosilicate glass coatings

The present paper reports on the development of a vitreous material with high near-infrared (NIR) emissivity. Silica-based glasses (SiO2, Na2O, Al2O3, K2O) with different Fe2O3 (hematite) contents are deposited on ceramic tiles as coatings and annealed at 1250 °C. Using the indirect radiometric measurement method, the emissivity of the materials was determined at room temperature, where the spectral directional reflectance of the coatings was measured. The samples possessing high emissivity values of 0.78–0.80 in the near-infrared are those with the highest Fe2O3 contents. Colorimetric test (L*a*b*), has revealed that the glass coating goes darker red by adding more amount of Fe2O3. XRD analysis has shown the magnetite, hematite, and nepheline crystallization phases in the glasses with Fe2O3 contents above 30 wt%. Readable aspects of FTIR absorbance spectra were found, which gave information about the structure variations of these glasses as a function of Fe2O3 content, also, SEM photographs displayed morphology of the prepared glass coatings.

Estimation of sea water salinity from dielectric measurements: Effect of temperature

Dielectric measurements have been carried out for distilled water and saline water solutions of salinities 10000, 20000, 30000, 40000 ppm, as well as sea water of Diu beach area, using Anritsu Shockline Vector Network Analyzer (VNA, model no: MS46322A) in the frequency range from 1 GHz to 20 GHz, over the temperatures of 20°, 30° and 40 °C. From the measured values of dielectric constant and dielectric loss, the values of tanδ, conductivity and emissivity of water solutions have been calculated. The variation in dielectric properties of water with salinity and temperature of measurement is compared with values calculated using Stogryn equations as well as Klein and Swift model and results are found to be in good agreement with corresponding values. From the dielectric loss values and the emissivity values of distilled water and saline water solutions at certain fixed frequencies, the salinity of sea water collected from Diu beach has been estimated to be 36,327 ppm which agrees very well with the physicochemical analysis report of laboratory.

On the energy potential of daytime radiative cooling for urban heat island mitigation

The objective of this paper is to present the potential of daytime radiative cooling materials as a strategy to mitigate the Urban Heat Island effect. To evaluate the cooling potential of daytime radiative cooling materials, 15 theoretical materials and seven existing materials were simulated: two radiative cooling materials, a coolmaterial, two white paints, a thermochromic paint and a construction material. The novelty of this study is that it shows that the optimal spectral characteristics of radiative cooling materials depending on the climate conditions and the type of application. A sensitivity analysis was performed to evaluate the impact of each wavelength emissivity on the ability to achieve sub-ambient radiative cooling. The sensitivity analysis comprised a total of 90 theoretical materials with 15 different wavelength combinations and 6 emissivity values. The heat transfer model, which includes conduction, convection, and radiation, was developed using a spectrally-selective sky model. Two conditions were considered: a very conductive surface and a highly insulated one. All the materials were simulated in two cities that suffer from the Urban Heat Island effect—Phoenix and Sydney. The mean surface temperature reduction achieved was 5.30 °C in Phoenix and 4.21 °C in Sydney. The results presented suggest that the type of application (active or passive) is a determinant factor in the design of radiative cooling materials. Modifying the spectra of the materials led to a substantial change in the cooling potential. A material that performs well in a dry climate as a passive solution could perform poorly as an active solution.

The impact of oxidation on the optical properties of Si–SiC materials

Silicon carbide is an interesting candidate for high-temperature solar receiver due to its high solar absorptivity and its resistance to oxidation in air. Its oxidation stays passive with the formation of a protective silica layer up to 1900 K. Nevertheless, silica presents a lower spectral emissivity than silicon carbide in the solar range. Therefore the growth of a silica layer may affect the values of the spectral emissivity and therefore the surface receiver thermal efficiency. We have investigated here how high-temperature ageing in air affects the spectral emissivity and the thermal efficiency of commercial Si–SiC materials. We were able to correlate the variations of the spectral emissivities to the advancement of the oxidation using scanning electron microscopy, ellipsometry and 3D profilometry. Especially we observed a significant improvement of the surface receiver thermal efficiency due to the increase of the surface roughness that increases the solar absorptivity.

Improved thermal expansion performance of Aluminum/polysiloxane/glass coatings with low infrared emissivity by zinc powder

Thermal expansion performance of Aluminum/polysiloxane/glass coatings with low infrared emissivity was improved by adding zinc powder. The influences of zinc powder on phase structure, composition, surface microstructure, thermal expansion, adhesion and infrared radiation of Aluminum/polysiloxane/glass coating was systematically studied. The thermal mechanical analysis indicated that thermal expansion coefficient can be adjusted by adding zinc powder in the coating. The tensile strength test results show that the matching of the thermal expansion could improve the adhesion strength of the coatings. As a result, compared with the coating without zinc powder, the adhesion strength was enhanced by 2.0 ± 0.4 MPa when the heat treatment temperature at 450 and 500 °C, and increased by 3.0 ± 0.4 MPa at 550 °C. Simultaneously, average infrared emissivity value of the coating with good thermal stability was about 0.20 in the 3–5 μm wavebands, and approximately 0.34 within 8–14 μm after heated at 550 °C. These results indicated that the good thermal expansion performance and low infrared emissivity coatings were obtained by adding zinc powder.

VO2-based active tunable emittance thermochromic flexible coatings.

This contribution reports, for what we believe is the first time, on VO2-based thin-film coatings on flexible Al substrates exhibiting a tunable positive emittance-switching Δε=(εH-εL)>0. More precisely, a layered stack of a-Si:H/SiO2/VO2 on flexible Al sheets presents minimum and maximum values of emissivity of about 0.18 and 0.57 at 40ºC and 83ºC, respectively, and hence allows an emittance-switching Δε of 0.39 and a relative variation Δε/εΛ of ∼217%. Such variations fit with the potential applications of such coatings as smart radiation devices in small satellites and spacecraft.

Numerical assessment of radiative heat transfer impact on pollutant formation processes in a compression ignition engine

An imposed solution in the development process of compression ignition engines is the use of numerical research employing Computational Fluid Dynamics (CFD). At the high operating temperatures in compression ignition engines, the radiative heat transfer influences the overall temperature profile and heat transfer, which also affects the formation processes of pollutants. For the radiative transfer calculation in this work, method of discrete ordinates (DOM) employing Finite Volume Method (FVM) is implemented with user functions into the AVL FIRE™ CFD code. The absorptivity and emissivity are described with the implemented Weighted Sum of Grey Gases Model (WSGGM) based on non-isothermal and nonhomogeneous absorption coefficient correlations for carbon dioxide, water vapour and soot. The implemented procedure is extended to work with moving meshes, parallel computing and rezoning procedure, which are needed to account the radiative heat transport in internal combustion engines. Additionally, the focus of this work is on the performed validation of calculated mean temperature, pressure, rate of heat release and emission results against the compression ignition engine experimental measurements. Results with the implemented radiation model showed lower peak temperatures for approximately 10 K, which resulted in around 18% lower nitrogen oxides concentrations, and up to 20% higher soot concentrations at the end of engine operating cycle. The most dominant impact of the radiative heat transfer on soot formation is visible at the crank angles, where peak temperatures occur. The performed parameter study of the piston and head wall emissivity values showed a reduction in mean in-cylinder pressure and NO mass fraction for a less reflective surface. From the conducted parameter analysis of ordinates number, the sufficient accuracy is achieved for simulations with eight ordinates, which resulted in approximately 50% increased computational time. Finally, it may be concluded that the combination of implemented models is useful to predict the heat transfer of internal combustion engine focussing on the radiative heat transport, which can be an important factor for the development of forthcoming internal combustion engines.

Coupling turbulent natural convection-radiation-conduction in differentially heated cavity with high aspect ratio

In this paper, the effect of a several combined heat transfer processes: turbulent natural convection, surface radiation and conduction, are investigated numerically in an air-filled three-dimensional (3D) differentially heated tall cavity. The objectives of this work is to analyse the effect of coupled of different heat exchanges on flow structures of turbulent natural convection, and to distinguish the most realistic thermal boundary conditions of internal walls providing thus more accurate results.The cavity is parallelepiped and extended with sides length 0.076 × 2.18 × 0.52 m. A temperature gradient between the lateral walls is subjected of ΔT=19.9°C., inducing a turbulent flow due to the high Rayleigh number (RaH = 2.03 × 1010). A three dimensional unsteady numerical simulations are performed by the finite volume method using the Shear Stress Transport (SST k-ω) model and using the P-1 thermal radiation model.The effect of surface thermal radiation on heat transfer and dynamic structure is examined through a different values of internal surface emissivity of ε = [0, 0.6] and the air is assumed non-participating medium. Also, different previously works concluded that the heat conduction of passive walls must be considered for more accurate prediction. However, the heat conduction is considered in the likewise direction by imposing a temperature distribution along adiabatic walls. In the present study, the thickness of horizontal walls is specified in order to consider the normal heat conduction as a new approach in physical modelling of an enclosed cavity.The present numerical results are compared to available experimental databases for the same flow configuration. A numerical predictions show that the emissivity of the internal walls influences essentially the flow structures close to the horizontal walls, without any effects on the flow in the core of the cavity. On the other hand, somewhat accurate numerical predictions are obtained with combined different heat transfer along internal walls of differentially heated cavity.

Temperature Measurement of Laser-Irradiated Metals Using Hyperspectral Imaging

Accurate noncontact surface-temperature measurements during laser-based materials processing remain challenging due to the difficulty of establishing reliable emissivity values as a function of temperature and wavelength. Direct measurement of emissivity is difficult, as the emissivity may be changing constantly in the laser-material interaction region, where the temperature gradients are extreme and surface displacement can complicate the measurement. Here, we present a hyperspectral imaging method using a multiwavelength camera to capture the spectral radiance in eight different bands and fit the wavelength-dependent radiance to Planck's law. Time-resolved temperature measurements during microsecond pulsed-laser irradiation of a metal plate made of the titanium alloy $\mathrm{Ti}$-6$\mathrm{Al}$-4$\mathrm{V}$ provide temperature information about the irradiated surface with an estimated accuracy of $\ifmmode\pm\else\textpm\fi{}10\mathrm{%}$. The extracted wavelength-dependent emissivity slope compares well with reported results for macroscale titanium melts obtained using IR spectroscopy, which measure temperature without any built-in assumptions about the emissivity. The results are directly applicable to temperature monitoring during welding, additive manufacturing, and semiconductor growth.

Artificial Neural Networks in Radiation Heat Transfer Analysis

Abstract In the Monte Carlo ray-trace (MCRT) method, millions of rays are emitted and traced throughout an enclosure following the laws of geometrical optics. Each ray represents the path of a discrete quantum of energy emitted from surface element i and eventually absorbed by surface element j. The distribution of rays absorbed by the n surface elements making up the enclosure is interpreted in terms of a radiation distribution factor matrix whose elements represent the probability that energy emitted by element i will be absorbed by element j. Once obtained, the distribution factor matrix may be used to compute the net heat flux distribution on the walls of an enclosure corresponding to a specified surface temperature distribution. It is computationally very expensive to obtain high accuracy in the heat transfer calculation when high spatial resolution is required. This is especially true if a manifold of emissivities is to be considered in a parametric study in which each value of surface emissivity requires a new ray-trace to determine the corresponding distribution factor matrix. Artificial neural networks (ANNs) offer an alternative approach whose computational cost is greatly inferior to that of the traditional MCRT method. Significant computational efficiency is realized by eliminating the need to perform a new ray trace for each value of emissivity. The current contribution introduces and demonstrates through case studies estimation of radiation distribution factor matrices using ANNs and their subsequent use in radiation heat transfer calculations.

Emissivity and absorption function measurements of Al2O3 and SiC particles at elevated temperature for the utilization in concentrated solar receivers

Solar thermal receivers collect and can store concentrated solar radiation using solid particles. Solid ceramic particles have shown to be a practical and efficient heat transfer media in solar-particle receivers, however, their emissivity and absorptivity at high temperatures are scarcely reported. This gap has led to large uncertainties in the assessment of solar thermal receivers’ efficiency. In this work, an experimental method was developed to measure the emissivity and absorption function of solar particles at elevated temperatures up to 1200 K. Two types of solar particles, aluminum oxide (Al2O3, ∼95% purity) and silica carbide (SiC, ∼99% purity), were studied, particularly aiming to understand the dependence of emissivity and absorption function on temperature. Using a heat transfer model, the emissivity of particles was evaluated based on the fitting of the cooling rate, while the particle absorption function was obtained by fitting of the heating rate, following a well-controlled heating radiation at 910 nm. It was found that the emissivity values of the two particles are independent of temperature, showing constant values of 0.75 ± 0.015 and 0.92 ± 0.012 for Al2O3 and SiC respectively, in the temperature from 300 to 1200 K. The absorption function was found to be increased nonlinearly with temperature for Al2O3, while that of SiC dropped slightly. These absorption functions are specified for 910 nm. Using the evaluated experimental values of emissivity and absorption function, the maximum temperature and the temperature rise time of micro-sized particles (hundreds of micrometers) under different radiation fluxes were simulated taking into account the effect of particle diameter.