Incident Radiation Flux Research Articles

Inactivation kinetics of dairy phages using photocatalytic paint under diverse environmental conditions and radiation sources

This article investigates the efficacy of a photocatalytic paint for bacteriophages inactivation under various levels of incident radiation flux, relative humidity and radiation sources. Two phages that infect lactic acid bacteria were selected: J-1, infective of Lacticaseibacillus casei ATCC 27139, and M13-G1b, infective of Streptococcus thermophilus G1b. Phage suspensions were deposited on coated and uncoated plates and exposed to radiation typically used for indoor illumination (λ = 360–720 nm). A first-order inactivation kinetics was proposed with respect to the Plaque Forming Units per mL (PFU/mL) that correlates the inactivation constant with the operating conditions. The kinetic constant of this novel model combines a potential function for the incident radiation flux and a logistic function for the relative humidity. The results showed that as these variables increased, phage inactivation turned higher for both uncoated and coated plates. Photonic and quantum efficiencies were also calculated for both phages, when treated with photocatalytic paint under UV-A radiation. The photonic efficiencies were 8.03 × 1012 PFU/Einstein for J-1 and 4.05 × 1012 PFU/Einstein for M13-G1b, while the quantum efficiencies were 1.19 × 1013 PFU/Einstein for J-1 and 6.03 × 1012 PFU/Einstein for M13-G1b. Good agreement was obtained between predictions of the proposed kinetic model and experimental data, with a Root Mean Square Error of 4.43 % for J-1 and 2.98 % for M13-G1b. The developed model would be useful to predict phage inactivation under diverse combinations of operating conditions levels in environments of dairy plants, different from those tested in this work.

Analytical formulations with experimental validation for determining the incident heat flux from firefronts

Any target exposed to a heat source receives a certain amount of heat flux, depending on the distance, view factor, characteristics of the source, and environmental properties. Incident heat flux is mainly characterized by firefront properties, e.g., flame dimensions, and its thermal attributes by fuel properties, topography, and meteorological factors. Predicting the incident heat flux from the firefronts is crucial for fire risk management and analytical and numerical fire modelling. Based on this specification, safe zones can be defined for elements such as unprotected individuals, firefighters, and buildings. Since the contribution of radiation and convection varies with the fire evolution, it is essential to specify them as a function of distance and slope. This study elaborates determination of radiation and convection for firefronts. Sets of laboratory-scale experiments were conducted using fuel beds of straw with a load of 1.5 kg/m2 on the slopes of 0°, 20°, and 40° measuring the incident radiative and total heat fluxes. The proposed methodology was validated using available approaches and correlations between the flame length and the acceptable safety distance (ASD) were established. Unlike the existing models, a nonlinear correlation between convection and radiation during the firefront evolution is proposed.

Considerations on measurement of bidirectional transmittance distribution function of thick samples over a wide range of viewing zenith angles

Abstract We delve into theoretical and experimental considerations for determining the spectral bidirectional transmittance distribution function (BTDF) of thick samples across a broad viewing zenith angle range. Nominally, BTDF is defined as the ratio of transmitted radiance to incident irradiance measured from the same plane. However, when employing thick samples for BTDF measurements, the viewing plane of the transmitted beam may shift from the front to the rear surface of the sample, altering the measurement geometry compared to using the sample front surface as the reference plane. Consequently, the viewing zenith angle from the sample rear surface increases relative to the sample front surface, and the sample-to-detector-aperture distance decreases by an amount corresponding to the sample thickness. We introduce a method for determining the BTDF of thick samples, considering the transformation of practical measurement results to a scenario where the measurements are conducted at a very large distance from the sample. To validate the method, we utilize a BTDF facility equipped with two instruments that significantly differ in their sample-to-detector-aperture distances. We evaluate the impact of a 2 mm sample thickness on the BTDF by assessing the ratio of transmitted and incident radiant fluxes as a function of viewing zenith angle relative to the sample rear surface. The evaluation is conducted in the wavelength range from 550 nm to 1450 nm in 300 nm steps, and in the viewing zenith angle range from −70° to 70° in 5° steps. Measurements are performed in-plane at an incident zenith angle of 0°. It is concluded that consistent determination of BTDF of a thick sample is possible by converting the experimental parameters of the real measurements at relatively short distances from the sample to correspond to those that would be obtained from measurements at very large distances from the sample.

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

Fire is the most frequent hazard to buildings. The current design methods for predicting the temperatures of structures in fire are originally developed for the standard fire that assumes a uniform gas temperature field and are invalid for natural fires with high non-uniform gas temperature fields. Localized fire is a typical natural fire with high non-uniform gas temperature field, which is often considered in fire safety design. There are currently no validated simple general models for calculating the heat transfer from localized fire to exposed structures. To address the need of design method, this paper develops a refined cylinder fire model for calculating the incident radiant heat fluxes on horizontal structural members inside and outside the flame region of a localized fire. The model uses a cylinder, centered at the fire plume axis, to represent the localized fire. The height of the cylinder is not fixed, different to any other fire models. The temperatures in the cylinder are highly non-uniform in three dimensions and are determined based on the classic fire plume theory. For radiation calculation, the cylinder is evenly divided into several elements along the radius and height. Each element is assumed to be a homogenous, isotropic, and absorbing-emitting (participating) graybody. By careful consideration of the spatial gas temperature distribution, the radiation properties (emissivity and transmissivity) of the elementary graybody, and the configuration factor between the elementary graybody and the horizontal target surface, the model can get relatively accurate and conservative incident radiant heat flux. The relative deviations against both the experiment data and numerical results are within ± 30 %. The model introduces a new concept of calculating the heat fluxes from fire to structures, is a relatively simple general model (compared with the sophisticated computational fluid dynamics models), and is more precise and accurate than other simple ones. The model is recommended for use in performance-based fire safety design.

Photoinactivation of jack bean (Canavalia ensiformis) urease in fresh human urine using dichromatic low-pressure UV irradiation

In source-separating sanitation systems, inhibiting urease activity prevents enzymatic urea hydrolysis and volatilisation of ammonia when urine is concentrated by evaporation. This study tested UV-based photoinactivation as a novel alternative to existing methods of inactivating urease that require dosing urine with acid, base or oxidants. The enzymatic activity of jack bean (Canavalia ensiformis) urease in water, synthetic fresh urine and real fresh urine was investigated, with and without a 15 W low-pressure UV lamp that emitted 185 nm and 254 nm radiation. In UV-free controls, urea was hydrolysed at a rate of 3.2 × 10−3 mmol mgurease−1 min−1, 3.3 × 10−3 mmol mgurease−1 min−1 and 2.0 × 10−3 mmol mgurease−1 min−1 in water, synthetic urine and real urine, respectively. In the presence of UV, no urease activity was detected in any matrix. A UV irradiation time of 1.3 and 3.3 min was needed for inactivating urease in water and synthetic urine, respectively, whereas an irradiation time of 71 min was needed for inactivating urease in real urine. Overall, the electrical energy demand for photoinactivation of urease in real human urine was estimated to be 29.1 kWh m−3. Photolysis and photo-oxidation of amino acid residues at the active site of the enzyme were likely reasons for inactivation. Organic metabolites in real urine affected photoinactivation by (i) absorbing radiation between 190 nm and 400 nm, which reduced incident radiant flux; and (ii) scavenging hydroxyl radicals, which impeded oxidative damage to the enzyme. Overall, the findings demonstrate the feasibility of on-site treatment using a low-pressure UV lamp for inactivating urease in freshly excreted urine.

Conduction-radiation heat transfer in a gray semi-transparent medium: combining integral transforms and discrete ordinate method

This work presents a novel approach to solve the unsteady one-dimensional coupled heat conduction-radiation problem for a gray semi-transparent, absorbing, emitting, and diffusing medium, non-linearly anisotropic, bounded by two gray parallel-plane surfaces that are diffuse in emission, and diffuse and specular in reflection. A combination of the Discrete Ordinate Method (DOM), to discretize the angular coordinate of the Radiative Transfer Equation (RTE), and the Generalized Integral Transform Technique (GITT), to solve the energy equation, is proposed as solution methodology. Results are presented in terms of the temperature field, incident radiation, hemispherical reflectance, and conductive, radiative and total heat fluxes. The versatility and the accuracy of the methodology are verified/ validated with solutions of the literature for different phase functions, conduction-radiation coupling parameters, and albedo, emphasizing the effects of these parameters, as well as, the characteristics of the present methodology for different kinds of quadrature rules. The results show that the combination DOM/GITT proved to be adequate as a tool for solving the governing equations of the coupled conduction-radiation problem.

The influence of feedback and convection on imposed heating conditions when using gas-fired radiant panels in fire testing

Gas-fired radiant panel arrays (RPAs) are a common experimental tool used in fire science and material testing. Unlike devices such as Cone Calorimeter or the Fire Propagation Apparatus (FPA), RPAs typically consume gaseous fuel within a porous medium through which fuel is burnt. When RPAs are used, thermal feedback from the surface of heated samples, as well as the effects of hot gases within the zone of convective influence of the RPA will cause an increase in the surface temperature of the RPA. To investigate this, experiments were conducted using a gas-fired RPA. Target samples made from vermiculite board, concrete, and a water-cooled aluminium plate were exposed to various severities of pre-calibrated incident radiant heat fluxes (HF). It was confirmed that the presence of a target sample led to an increased surface temperature for the RPA of nearly 80 °C (for a calibrated incident HF of 144 kW/m2). This increased surface temperature results in an incident HF nearly 78% higher than the pre-calibrated value at the sample's surface. Based on the results in this paper, a correction method has been proposed which can be used by gas-fired RPA users to account for the increase in incident heat fluxes.

Reflector Design for Simulating Varying Heat Flux on Nose Cap of a Re-entry Module

For thermo-structural tests of a nose cap for a re-entry module accurate simulation of time and space varying heat flux is essential for generating the actual temperature gradients as expected in flight. Temperature gradient simulations along with simulated structural loads are essential for testing the structural integrity of the C-C nose cap.
 Contoured reflectors are essential for obtaining spatial distribution of incident heat flux. For realizing the reflector for thermo-structural testing, it is important to design radiation reflectors that will generate required heat flux envelope along the nose cap geometry. Reflector design for simulating varying heat flux on re-entry nose cap has been carried out by estimating view factor between nose cap and for different geometries of reflector.
 Design could be accomplished by making use of view factor algebra. Elemental heat flux values were validated with literature data and methodology for reflector heat flux design was validated against test data. With single flat reflectors and multiple flat reflectors, the required spatial variation of incident radiative heat flux could be realized efficiently. View factor variation is compared with heat flux variation along the nose cap. It is recommended practice to have multiple reflectors for simulating required varying heat flux on the nose cap due to better flexibility.

Direct hard X-ray photodetector with superior sensitivity based on ZnGa2O4 epilayer grown by metalorganic chemical vapor deposition

In this work, we have fabricated a highly sensitive direct irradiating X-ray photodetector (DXPD) based on Zinc Gallium Oxide (ZnGa2O4) epilayers with a metal-semiconductor-metal structure. The ZnGa2O4 epilayers were grown on a c-plane sapphire substrate by metalorganic chemical vapor deposition (MOCVD). To test the DXPD's capabilities, we subjected it to a synchrotron hard X-ray source with an energy of 10 keV, and measured incident radiation flux ranging from 5.7✕107 to 4.6 ✕1011 counts/sec. The effect of changing the applied bias voltage on the time response of the DXPD was investigated. The sensitivity of hard XPDs was compared using gallium oxide (β-Ga2O3) epilayer grown by MOCVD. The results showed that ZnGa2O4 DXPD had approximately 104 times greater sensitivity than the β-Ga2O3 based XPD. ZnGa2O4 based detectors also exhibited remarkable sensitivity of 2.87 × 109 μC Gyair−1cm−2 for the incident flux of 5.7✕107 counts/sec at 15 V. Additionally, the sensitivity was examined in terms of applied bias and dose rate. Based on these observations, it can be concluded that ZnGa2O4 epilayers grown by MOCVD hold immense potential for use in high-performance hard XPDs.

Computational modeling of CO2 conversion by a solar-enhanced microwave plasma reactor

The use of renewable energy to convert carbon dioxide (CO2) into higher-value products can help meet the demand for fuels and chemicals while reducing CO2 emissions. Solar-Enhanced Microwave Plasma (SEMP) CO2 conversion aims to combine the scalability and sustainability of solar thermochemical methods with the high efficiency and continuous operation of plasmachemical approaches. A computational study of a built SEMP reactor operating with up to 1250 W of microwave power together with up to 525 W of incident solar power at atmospheric pressure is presented. The study is based on a fully-coupled 2D computational model comprising the description of fluid flow, heat transfer, Ar-CO2 chemical kinetics, energy conservation for electrons and heavy-species, electrostatics, and radiative transport in participating media through the discharge tube, together with the description of the microwave electromagnetic field through the waveguide and the discharge tube. Numerical simulations reveal that the plasma is concentrated near the location of incident microwave energy, which is aligned with the radiation focal point, and that CO2 decomposition is highest in that region. The incident solar radiation flux leads to more uniform distributions of heavy-species temperature with moderately greater values throughout most of the discharge tube. Modeling results show that, at 700 W of electric power, conversion efficiency increases from 6.8% to 10.0% with increasing solar power from 0 to 525 W, in good agreement with the experimental findings of 6.4% to 9.2%. The enhanced process performance is a consequence of the greater power density of the microwave plasma due to the absorption of solar radiation.

Mitigation of firefighters’ skin burn injuries utilizing auxiliary measures

The improvement in the thermal resistance of firefighter’s outer garments has been traditionally achieved with the implementation of phase change materials or aerogel as an added protective measure. This study proposes supplementary novel cost-effective measures to enhance the thermal resistance of conventional firefighter outer garments. The proposed measures consist of auxiliary protective layers of meta-aramid fabric of a plain weave and a honeycomb structure. A custom built vertically oriented bench-scale apparatus was used to simulate extreme to life-threatening fire environments characterized in terms of an incident radiative flux of 84 kW/m2 and 126 kW/m2. The fluctuations in experimental heat flux density were treated by employing a Gaussian empirical model. The heat dissipation rate within the skin layers was predicted with a numerical model based on finite element methodology. The skin burns were classified with Henrique’s integral. The conventional outer garment when exposed to 84 kW/m2 and 126 kW/m2 resulted in a superficial second and third-degree burn. The auxiliary layers, in conjunction with the outer garment, mitigated second and third-degree burns. The meta-aramid fabric of a plain weave exhibited better thermal resistance than the honeycomb structure layer. The proposed measures reduced the epidermis temperature by 32%. An inner garment made of meta-aramid fabric is recommended to be worn concurrently with an outer protective suit for severe fire incidents due to its relative ease of use. Honeycomb structure layers are not recommended due to their weak structure and restriction in mobility.

Проблемы измерения потоков энергии излучения на объектах транспортной инфраструктуры с излучающей плазмой

Purpose: Transport infrastructure objects comprise numerous technical devices containing radiating plasma. They include visible and spectral radiation sources, switching devices at traction substations, high-temperature heat exchangers and combustion chambers. During experimental study of such devices, the measurements of power and spectral composition of radiation emitted by plasma are carried out. For this, as a rule, photodiodes of small sizes are used, installed at a certain distance from plasma formation. The purpose of the present work is to establish relationship between plasma emission power and radiation flux amount incident on photodiode working surface. Methods: To solve the set task, the method of direct integration of radiation transfer equation in homogeneous plasma structure assumption, but in the absence of local thermodynamic equilibrium presence assumption, is used. The cases of reflecting and absorbing surfaces, limiting a plasma, are considered. Results: Explicit expressions are found for radiation flux which exits plasma formation surface and for flux incident on photodiode surface. The dependence for the ratio of the values of these radiation fluxes to plasma geometric sizes and optical thickness is numerically studied. For the case of reflecting surfaces that bound plasma, simple asymptotic expression is found for ratio value for the fluxes and applicability field of the expression is determined. Practical significance: The ratios, which establish relationship between plasma radiation power and power value for radiation flux incident on photodiode working surface, make it possible to solve the main task of the experimental study of plasma formations — the restoration of plasma characteristics according to photocurrent measurement results. Obtained in the work results can be used at experimental study of technical devices containing emitting plasma.

Investigation of radiation heat transfer in a CAN combustion chamber of a micro gas turbine

Thermal radiation plays a key role in heat transfer between the flame and its surroundings. Measuring the radiation flux from the flame in the chamber is challenging due to the impact of the walls. Radiation emitted from the walls and the reflection of flame radiation from the walls interfere with the measurement of flame radiation. In this paper, various parameters that affect flame radiation are investigated. These studies are based on wall incident radiation and wall radiation heat flux. A theoretical method is proposed to calculate the flame radiation and compared it with the CFD simulation results to confirm its accuracy. The DO radiation model and a steady Flamelet combustion model with modified k-ε turbulence have been used to simulate the can-type combustion chamber.  The CFD results were in good agreement with their theoretical ones, and the estimation of flame emission was accurately acceptable. It found out that in the entire temperature range of the wall temperature investigated in this type of combustion chamber, the radiation from the wall never deflects more than 10% of the flame radiation.

Thermo-mechanical analysis of a porous volumetric solar receiver subjected to concentrated solar radiation

The damage caused by high working and non-uniform temperature distributions is one of the major obstacles to the development of receivers exposed to concentrated solar radiation. The thermal and mechanical performance of a typical porous Silicon Carbide volumetric receiver with foam structure is investigated in the present study with a coupled thermo-mechanical model. The developed model includes coupling of fluid flow, thermal and mechanical models to determine flow field, temperature and stress distributions. The main objective is to investigate the effects of various geometric, structural and design parameters on the absorber's thermal and mechanical performance and to identify the failure-prone regions when the absorber works under steady-state conditions. The effects of porosity, pore size, inlet velocity, absorber's geometrical dimensions, and incident solar flux distribution on the receiver's performance are investigated in detail. It is observed that higher porosities, pore sizes and inlet velocities result in lesser thermal stresses in the porous absorber. The uniformity of the incident radiation flux also reduces thermal stresses and improves the absorber's performance. The near-wall region at the inlet is found to be most prone to mechanical failure. The results of the study provide important conclusions to help in the selection of the proper set of parameters that ensure the efficient, safe and reliable working of the receiver.

Thermal management of solar photovoltaic panels using a fibre Bragg grating sensor-based temperature monitoring

Solar photovoltaic (PV) performance is affected by increased panel temperature. Maintaining an optimal PV panel temperature is essential for sustaining performance and maximizing the productive life of solar PV panels. Current temperature sensors possess a long response time and low resolution and accuracy. Advanced fibre-optic sensors offer distinct advantages of greater accuracy, a more comprehensive range, and a very high sampling rate. The present experimental work focuses on fibre Bragg grating sensor-based solar PV panel temperature monitoring. The unique capabilities of fibre-optic sensors are demonstrated by studying the rapid perturbations in panel temperature over time for indoor and outdoor conditions. The effects of incident radiation flux and the inclination angle on panel temperature are analyzed. Temperature sensitivity of 6 pm/°C is obtained. The results are helpful in dynamic monitoring of panel temperature, understanding the thermal interactions at the microscale level, and streamlining the measured temperature of multiple panels on solar farms. Thus, the proposed advanced method of FBG-based temperature monitoring of solar panels could be helpful to operate an integrated cooling system to improve the performance of solar panels.

Numerical results for radiative heat transfer in finite cylindrical medium with isotropic scattering

In recent years, the interest in radiative heat transfer in cylindrical media has increased primarily because of its several applications related to combustion chambers, furnaces, and high temperature heat exchangers. Although there are many papers dealing with the radiative transfer in such geometry, there is lack of high precision benchmarks. Such scarcity is related to the fact that some researches present inaccurate results and most published works are limited to presenting results only in graphics. The shortage is more evident in the case of multidimensional problems, like those in which incident radiation and radiative heat fluxes vary in the axial direction. These problems can be approached in many ways; in the integral formulation, the angular variables are completely eliminated by integration over the solid angle, which allows the elimination of the ray effect and the consequent obtainment of more accurate numerical results. A strategy that can be used simultaneously with the integral formulation is the use of the singularity-subtraction technique with the Nyström method, which provides high quality numerical results with relatively low computational times if combined with mathematical refinements. Following this methodology, in the present research, radiative heat transfer problems in finite cylindrical media with isotropic scattering are solved. High precision numerical results for incident radiation and radiative heat fluxes in the radial and axial directions are provided and validated by comparing with results available in the literature.

Aerosols consistently suppress the convective boundary layer development

Aerosols with different vertical distribution and various optical properties induce diverse heating rates and thereby affecting convective boundary layer (CBL) development. Our results showed consistent CBL-suppression of aerosols during daytime with numerical experiments, in which aerosols were specified at different heights with synthesized single scattering albedo from 64 studies and asymmetry factor from 20 studies globally. Absorbing aerosols concentrated below but close to the CBL top had the strongest suppression effect on CBL development relative to that concentrated near surface or above CBL. Aerosol cooling effect by attenuating incident solar radiation and surface heat flux exceeded its warming effect by reheating the atmosphere layer with absorbed shortwave radiation, and eventually declined net heating rate, which inhibited CBL development, lowered mixed-layer potential temperature and stabilized atmospheric stratification. Stove effect of absorbing aerosols (CBL enhancement) under a zero background aerosol extinction coefficient is negligible for dominant dome effect (CBL suppression) which consistently suppresses CBL development regardless of aerosol vertical height and background aerosol extinction coefficient. Our study also highlighted the importance of specifying background aerosol extinction coefficient in numerical experiments for accurate assessment of aerosol radiative forcing and CBL-aerosol interactions.

Получение хлопьев высокого пищевого достоинства из зерна ржи

The relevance of the production of grain products of a high degree of readiness and the expansion of the raw material base through the use of rye grain is shown. Methods for determining the fractional composition of proteins according to A.I. Ermakov, the content of water-soluble protein according to O.H. Lowry, dextrins according to M.P. Popov and E.F. Shanenko, fiber according to Kurshner and Ganak were used. Rational modes of IR processing of rye grain are substantiated when obtaining a new product from it in the form of flakes with high nutritional and consumer advantages. The effect of IR treatment on the physical and biochemical properties of rye grain has been studied. It is shown that the main parameters determining the modes of IR processing of rye grain are the grain moisture, the density (intensity) of the incident radiant energy flux and the irradiation time. The influence of various modes of IR processing on carbohydrates and proteins of rye grain has been studied. The effect of the intensity of IR processing of rye grain on the degree of starch dextrinization and on the density of grains is shown. The effect of IR treatment on the change in the solubility of proteins as a result of their denaturation is investigated. The effect of IR treatment modes on the degree of denaturation and fractional composition of rye grain proteins has been studied. The effect of grain flattening on the carbohydrate complex and the intensification of IR processing on the consumer advantages of flakes has been studied. The effect of IR treatment on the acidity of water and alcohol extracts, fiber content has been studied. Physicochemical changes in rye grain during its flattening into flakes after IR treatment have been studied. The production of a new fast food product in the form of flakes with high nutritional value and high fiber content, which can be used as a dry breakfast, is justified.

Different Influencing Mechanisms of Two ENSO Types on the Interannual Variation in Diurnal SST over the Niño-3 and Niño-4 Regions

AbstractIn this paper, the different effects of the eastern equatorial Pacific (EP) and central equatorial Pacific (CP) Ocean El Niño–Southern Oscillation (ENSO) events on interannual variation in the diurnal sea surface temperature (SST) are explored in both the Niño-3 and Niño-4 regions. In the Niño-3 region, the diurnal SST anomaly (DSSTA) is negative during both EP and CP El Niño events and becomes positive during both EP and CP La Niña events. However, the DSSTA in the Niño-4 region is positive in El Niño years and negative in La Niña years, which is opposite to that in the Niño-3 region. Further analysis indicates that the incident shortwave radiation (SWR), wind stress (WS), and upward latent heat flux (LHF) are the main factors causing the different interannual variations in the DSST. In the Niño-3 region, decreased SWR and increased LHF lead to a negative DSSTA in EP El Niño years, and enhanced WS and increased LHF cause a negative DSSTA in CP El Niño years. Conversely, in that same region, increased SWR and decreased LHF lead to a positive DSSTA in EP La Niña years, and reduced WS and decreased LHF cause a positive DSSTA in CP La Niña years. In the Niño-4 region, the reduced trade wind plays a key role in producing the positive DSSTA, whereas the decreased SWR has an opposite effect that reduces the range of the DSSTA during both EP and CP El Niño events, and conversely the enhanced trade wind plays a key role in producing the negative DSSTA, whereas the increased SWR has an opposite effect that increases the range of the DSSTA during both EP and CP La Niña events.

Shortwave Radiation Calculation for Forest Plots Using Airborne LiDAR Data and Computer Graphics.

Forested environments feature a highly complex radiation regime, and solar radiation is hindered from penetrating into the forest by the 3D canopy structure; hence, canopy shortwave radiation varies spatiotemporally, seasonally, and meteorologically, making the radiant flux challenging to both measure and model. Here, we developed a synergetic method using airborne LiDAR data and computer graphics to model the forest canopy and calculate the radiant fluxes of three forest plots (conifer, broadleaf, and mixed). Directional incident solar beams were emitted according to the solar altitude and azimuth angles, and the forest canopy surface was decomposed into triangular elements. A ray tracing algorithm was utilized to simulate the propagation of reflected and transmitted beams within the forest canopy. Our method accurately modeled the solar radiant fluxes and demonstrated good agreement (R2 ≥ 0.82) with the plot-scale results of hemispherical photo-based HPEval software and pyranometer measurements. The maximum incident radiant flux appeared in the conifer plot at noon on June 15 due to the largest solar altitude angle (81.21°) and dense clustering of tree crowns; the conifer plot also received the maximum reflected radiant flux (10.91-324.65 kW) due to the higher reflectance of coniferous trees and the better absorption of reflected solar beams. However, the broadleaf plot received more transmitted radiant flux (37.7-226.71 kW) for the trees in the shaded area due to the larger transmittance of broadleaf species. Our method can directly simulate the detailed plot-scale distribution of canopy radiation and is valuable for researching light-dependent biophysiological processes.