Thermal Radiation Research Articles

Reversible esterification process in Casson nanofluids: A numerical analysis of non-newtonian hydromagnetic flow

A computational mechanism has been formulated to scientifically analyze the phenomenon of combined convection in the occurrence of magnetohydrodynamic flow behavior of Casson nanofluid. This study emphasizes the trajectory of the nanofluid along a stretching sheet with nonlinear permeability, while considering additional physical effects such as reversible chemical reaction, thermal radiation, energy source/sink, suction and viscous dissipation. In this study, we have additionally integrated the nanofluid paradigm proposed by Buongiorno, which encompasses the repercussion of thermophoresis along with Brownian motion. The utilization of appropriate similarity renovations serves the purpose of recasting the dominant multivariate differential equations to a collection of nonlinear differential equations in single variable. The Runge–Kutta shooting mechanism is implemented for the intention of numerically determining the unknown boundary conditions. The solution to the dominant equations was obtained by employing the fourth-order Runge–Kutta technique and to ensure the dependability of the outcomes, the bvp4c method was employed. The graphical and tabulated observations are presented herein to facilitate a comprehensive analysis of the underlying physical characteristics inherent in the problem at hand. The utilization of the Casson parameter has been found to be advantageous in the reduction of shear stress rate, along with the enhancement of mass and energy transfer rates. Additionally, the application of suction has been observed to be beneficial in the enhancement of Sherwood number and energy transfer rate. Within the scope of the context of the esterification process, the purpose of this proposal is to evaluate the impact that numerous arithmetical values exert on the temperature field, the velocity profile and the volumetric concentration. An in-depth graphical analysis that takes into account the relevant physical consequences is used to evaluate the most important factors that relate to the physical quantities that describe the contours of temperature, velocity and concentration. In addition to being accompanied by their respective explanations, the tabular portrayal of the local Sherwood number, shear stress rate along with local Nusselt number all feature in this paper. There is a clear distinction that can be made between irreversible and reversible flows in the evaluation of the local Sherwood number, rate of shear stress and local Nusselt number. This differentiation is brought about by taking into analysis thermophoresis parameter, Brownian motion parameter and suction parameter. The results that were produced from the theoretical simulations have significant repercussions for a variety of fields that are related to energy engineering. The findings derived from the analysis indicate a negative correlation between the Brownian motion parameter and both irreversible and reversible flow in terms of rate of energy transfer and shear stress rate. It is imperative to highlight that reversible flow holds greater significance in comparison to irreversible flow.

Exploring nanoparticle dynamics in binary chemical reactions within magnetized porous media: a computational analysis

Artificial Neural Networks are incredibly efficient at handling complicated and nonlinear mathematical problems, making them very useful for tackling these challenges. Artificial neural networks offer a special computational architecture that is extremely valuable in disciplines like biotechnology, biological computing, and computational fluid dynamics. The present work investigates the applicability of back-propagation artificial neural networks in conjunction with the Levenberg-Marquardt algorithm for evaluating heat transmission in hybrid nanofluids. This work focuses on the computational analysis of a MgO + GO/EG hybrid nanofluid’s steady mixed convection flow over an exponentially stretched sheet, considering multiple slip boundary conditions, thermal conductivity, heat generation, and thermal radiation. A nonlinear system of ordinary differential equations is produced from the basic associated partial differential system by performing the proper exponential similarities modifications. For generating benchmark datasets, the resulting ordinary differential equations are processed employing the bvp4c method. Considering benchmark datasets set aside for training (70%), testing (15%), and validation (15%), the Levenberg-Marquardt algorithm, which employs back-propagation in artificial neural networks, is implemented. The accuracy of the suggested strategy for handling nonlinear problems is verified utilizing mean squared error, error histograms, and regression analysis, which are all used to evaluate the methodology. Outstanding agreement is seen when ANN outputs are compared to numerical results. The flow properties, including temperature, velocity, and concentration profiles, are shown graphically and numerically. For practical purposes, it is therefore essential to analyze the flow and heat transfer in hybrid nanofluids over exponentially extending and shrinking surfaces under mixed convection and heat source scenarios. Hybrid nanofluid problems have a wide range of practical and industrial applications, such as medication delivery, manufacturing, microelectronics, nuclear plant cooling, and marine engineering.

Significance of Arrhenius activation energy on three-dimensional unsteady nanofluid flow with nonlinear thermal radiation and Joule heating via wavelet technique

Significance of Arrhenius activation energy on three-dimensional unsteady nanofluid flow with nonlinear thermal radiation and Joule heating via wavelet technique

The Role of Two Models of Thermal Radiation and Variable Properties on Thermal Explosion Critical and Transition Conditions of the Optically Thin Droplets

ABSTRACT Determining the criticality and disappearance of optically thin droplets (gas phase) by thermal explosions is crucial for maintaining thermal stability in various industrial and nonindustrial applications. The governing nonlinear ordinary differential equations of this problem make use of two distinct approximation models for thermal radiation loss, which were completed by Cogley et al. and Sohrab et al. Two methods of solving the problem – the Semenov method and the inflection point method – are used to identify the circumstances of criticality and disappearance of criticality (transition conditions). The governing equations utilize the use of the temperature-dependent Arrhenius frequency factor of the reaction and the thermal conductivity of the gas. The analytical solution of the equations yields the transitional values of the distinctive parameters at various initial conditions. Numerical methods are used to determine the equation’s exact solution. At specific initial conditions, the impact of θo, θa, γSh,F, and αSh,F on the temperature-time histories of ignition (supercritical region), non-ignition (subcritical region), and the critical boundary between them is derived. Notable effects on the ignition, non-ignition, and critical temperatures and times include the changing frequency of the reaction, the gas thermal conductivity, and two approximation models of radiation heat loss. The two radiation heat loss approximation models of the analytical and numerical findings are compared.

Shape factor and thermal radiation effects on convective MHD flow of Casson blood ternary hybrid nano‐fluid through a stretched rotating rigid disk

AbstractThe mathematical modeling of blood flow with the incorporation of ternary hybrid nanoparticles (i.e., titania, silica, and alumina nanoparticles) is the focus of this work. The flow of blood is simulated using the Casson fluid model. The impacts of ternary hybrid nanoparticles, shape factor, and Geometry of solid nanoparticles are visualized and investigated. The momentum and thermal characteristics of a flowing liquid are determined by considering magnetization, porosity, and nonlinearized radiating thermal flux. The basic partial differential equations resulting from mathematical modeling are turned into non‐linear ordinary differential equations using suitable velocity transforms. The derived nonlinear equations are then numerically calculated using the 4th‐5th order Runge‐Kutta‐Fehlberg method with the shooting technique and analytically solved by the Adomian decomposition method (ADM). The effects of the factors involved on the dimensionless profiles produced are fully addressed. It is found that the Skin friction factor and heat transfer rate in the radial direction upsurge with the augment of both rotation parameter and nanoparticles volume fraction; however, the Skin friction factor drops in the azimuthal direction. Also, results obtained reveal an enhancement in the local Nusselt number with the upsurge in the magnitude of radiation parameter, Rd, solid nanoparticles concentration, , shape factor value, s, and disk temperature, . For validation, the outcomes of this inquiry were compared to the outcomes of the HAM‐based Mathematica software. In addition, the acquired analytical DRA data are compared to numerical RKF45 values and those given in the literature.

Performance of photovoltaic panels with different inclinations under uniform thermal loading

Integrating photovoltaic (PV) panels with different tilt angles in building envelopes or roofs is widely employed for environmental sustainability. However, little is known about the influence of different tilt angles on the thermal failure of the photovoltaic façades or roofs in fire conditions. A total of 15 four-edge shielded PV panels (300 × 300 × 4.7 mm3), with five different inclinations of 0°, 15°, 30°, 45° and 60°, were heated to fail using a uniform radiant panel. Measurements were taken to track glass thermal breakage, surface temperatures, incident heat flux and failure characteristics. The glass fracture and pyrolysis of the internal thermoplastic materials were observed under thermal radiation. The average breakage time of glass in PV panels showed an increasing trend with increasing inclination of the PV panels. Moreover, when the PV panels were tilted beyond 30°, the time to failure increased more significantly. The maximum temperature difference and heat flux that the PV panels can withstand were primarily measured within the range of 61–84 °C and 8–15 kW/m2, respectively. Finally, the test results were simulated by a finite element method (FEM) model, calculating the heat transfer and thermal stress of PV panels: the average errors concerning temperature distributions and failure times were smaller than 15 % compared with the experimental results.

Infrared emissivity measurement methods considering target reflective characteristics

Emissivity measurements are of great significance for infrared thermal radiation and infrared remote sensing. However, traditional methods often face challenges such as difficulties in non-contact measurement, small measurement areas, and unsuitability for non-Lambertian surfaces. To address these issues, we propose the reflective distribution model integral method (RDMIM). This method is based on a reflective distribution model using the scattering-reflective deviation angle (SRDA). By regressing and integrating the object’s reflective distribution model, it achieves accurate non-contact measurement of non-Lambertian surfaces under normal temperature conditions. Additionally, the measurement scheme has been further optimized to improve measurement efficiency while ensuring the accuracy of the model regression. Finally, the proposed RDMIM method has been validated through experimental measurements. The results have shown that this method has advantages in non-contact and large-area measurements. Moreover, the systematic error is smaller when the reflective characteristics of the reference body and the target are relatively similar.

Investigation of heat generation and radiation effects on boundary layer flow of Prandtl liquid with Cattaneo–Christov double diffusion models

In this analysis, a bidirectional stretched sheet is used to produce a 3D\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal{D}$$\\end{document} flow of Prandtl liquid with improve mass diffusion and heat conduction models. This study advances knowledge of magnetohydrodynamics, radiation impacts, and heat production in fluid dynamics and transport processes. The Prandtl fluid model is critical for modeling non-Newtonian fluids, capturing its viscoelastic features, and allowing for precise simulation in industrial applications. It gives a mathematical foundation for analyzing complex fluid behaviors, which is necessary for optimizing operations utilizing such fluids. It uses the boundary layer method to simplify the fundamental equations and Cattaneo–Christov double diffusion models. The optimal homotopy analysis method is used to solve nonlinear ODEs caused by non-dimensional similarity variables. This investigation undertakes the calculation of drag coefficient for surfaces mass transfer rates and heat transfer rates proximate to the solid boundary. Furthermore, it conducts a comprehensive analysis of the influences exerted by various parameters on concentration and temperature profiles employing graphical representations for a rigorous examination. The Prandtl fluid model describes the viscoelastic characteristics of non-Newtonian fluids through constitutive equations, dimensional evaluation, and numerical simulations, which are frequently validated by experiments. The results show that changes in thermal and concentration relaxation parameters are accompanied by a decline in temperature. Temperature field rises as the thermal radiation parameter and heat generation increases. The work's novelty consists in its advanced modeling of Prandtl non-Newtonian fluids via Cattaneo–Christov double diffusion models, which incorporate magnetohydrodynamics and radiation effects and use optimal homotopy analysis for accurate parametric analyses of heat and mass transfer.

From the Shadows: The Impact of Nightside Thermal Emission on Ultrahot Jupiter Transmission Spectrum Retrievals

Transmission spectroscopy is the most widely used technique for studying exoplanet atmospheres. Since the planetary nightside faces the observer during a transit, highly irradiated giant exoplanets with warm nightsides emit thermal radiation that can contaminate transmission spectra. Observations of ultrahot Jupiters in the near- and mid-infrared with JWST are especially susceptible to nightside contamination. However, nightside thermal emission is generally not considered in atmospheric retrievals of exoplanet transmission spectra. Here, we quantify the potential biases from neglecting nightside thermal emission in multidimensional atmospheric retrievals of an ultrahot Jupiter. Using simulated JWST transmission spectra of the ultrahot Jupiter WASP-33b (0.8–12 μm), we find that transmission spectrum retrievals without nightside emission can overestimate molecular abundances by almost an order of magnitude and underestimate the dayside temperature by ≳400 K. We show that a modified retrieval prescription, including both transmitted light and nightside thermal emission, correctly recovers the atmospheric properties and is favored by Bayesian model comparisons. Nightside thermal contamination can be readily implemented in retrieval models via a first-order approximation, and we provide formulae to estimate whether this effect is likely to be significant for a given planet. We recommend that nightside emission should be included as standard practice when interpreting ultrahot Jupiter transmission spectra with JWST.

Robust constraints on the physics of the MeV emission line in GRB 221009A from optical depth arguments

ABSTRACT The brightest-of-all-time gamma-ray burst (GRB), GRB 221009A, is the first GRB observed to have emission line (up to 37 MeV) in its prompt emission spectra. It is naturally explained as $e^-/e^+$ annihilation line that was Doppler boosted in the relativistic jet of the GRB. In this work, we repeatedly apply the simple optical depth argument to different physical processes necessary to produce an observable $e^-/e^+$ annihilation line. This approach results in robust constraints on the physics of the line: We conclude that in GRB 221009A, the $e^-/e^+$ pairs were produced at a radius greater than $4.3\times 10^{15}$ cm from the central engine, and annihilated in a region between $1.4\times 10^{16}$ and $4.3\times 10^{16}$ cm. From these constraints, we established a self-consistent picture of $e^-/e^+$ production, cooling, and annihilation. We also derived a criterion for pair production in the GRB prompt emission: $E_{\rm {iso}} \gtrsim 3.3\times 10^{53} E_{\rm {peak},100} (1+z) R^2_{\rm {prod},16}~\text{erg}$. Using this criterion, we find tens of candidate GRBs that could have produced $e^-/e^+$ in prompt emissions to annihilate. GRB 221009A is with the highest likelihood according to this criterion. We also predict the presence of a thermal radiation, with a time-evolving blackbody temperature, sweeping through soft X-ray during the prompt emission phase.

The GRAZ Method—Determination of Urban Surface Temperatures from Aerial Thermography Based on a Three-Dimensional Sampling Algorithm

A novel method to derive surface temperatures from aerial thermography is proposed. Its theoretical foundation, details regarding the implementation, relevant sensitivities, and its application on a day and night survey are presented here. The method differs from existing approaches particularly in two aspects: first, a three-dimensional sampling approach is used to determine the reflected thermal radiation component. Different surface classes based on hyperspectral classification with specific properties regarding the reflection and emission of thermal radiation are considered in this sampling process. Second, the method relies on a detailed, altitude-dependent, directionally and spectrally resolved modelling of the atmospheric radiation transfer and considers the spectral sensitivity of the sensor used. In order to accurately consider atmospheric influences, the atmosphere is modelled as a function of altitude regarding temperature, pressure and greenhouse gas concentrations. The atmospheric profiles are generated specifically for the time of the survey based on measurements, meteorological forecasts and generic models. The method was initially developed for application in urban contexts, as it is able to capture the pronounced three-dimensional character of such environments. However, due to the detailed consideration of elevation and atmospheric conditions, the method is also valuable for the analysis of rural areas. The included case studies covering two thermographic surveys of city area of Graz during daytime and nighttime demonstrate the capabilities and feasibility of the method. In relation to the detected brightness temperatures apparent to the sensor, the determined surface temperatures vary considerably and generally cover an increased temperature range. The two processed surface temperature maps of the city area of Graz are finally used to validate the method based on available temperature recordings.

Blood Based Magnetohydrodynamic Casson Hybrid Nanofluid Flow on Convectively Heated Bi-Directional Porous Stretching Sheet with Variable Porosity and Slip Constraints

Abstract Fluid flow through porous spaces with variable porosity has wide-range applications, notably in biomedical and thermal engineering, where it plays a vital role in comprehending blood flow dynamics within cardiovascular systems, heat transfer and thermal management systems improve efficiency using porous materials with variable porosity. Keeping these important applications in view, in current study blood based hybrid nanofluid flow has considered on a convectively heated sheet. The sheet exhibits the properties of a porous medium with variable porosity and extends in both the x and y directions. Blood has used as base fluid in which the nanoparticles of Cu and CuO have been mixed. Thermal radiation, space-dependent, and thermal-dependent heat sources have been incorporated into the energy equation, while magnetic effects have been integrated into the momentum equations. Dimensionless variables have employed to transform the modeled equations into dimensionless form and facilitating their solution using bvp4c approach. It has concluded in this study that, both the primary and secondary velocities augmented with upsurge in variable porous factor and declined with escalation in stretching ratio, Casson, magnetic and slip factors along x- and y-axes. Thermal distribution has grown up with upsurge in Casson factor, magnetic factor, thermal Biot number and thermal/space dependent heat sources while has retarded with growth in variable porous and stretching ratio factors. The findings of this investigation have been compared with the existing literature, revealing a strong agreement among present and established results that ensured the validation of the model and method used in this work.

Ideal Photothermal Materials Based on Ge Subwavelength Structure.

Photothermal materials often prioritize solar absorption while neglecting thermal radiation losses, which diminishes thermal radiation conversion efficiency. This study addresses this gap by introducing a germanium (Ge) subwavelength structure (SWS) designed to optimize both solar absorption and infrared emissivity. Using a self-masked reactive ion etching (RIE) technique, we achieved a peak absorption of 98.8% within the 300 nm to 1800 nm range, with an infrared emissivity as low as 0.32. Under solar illumination of 1000 W/m2, the structure's temperature increased by 50 °C, generating a heating power of 800 W/m2. Additionally, it demonstrated good mechanical and thermal stability at high temperatures and possessed a hydrophobic angle of 132°, ensuring effective self-cleaning. These characteristics make the Ge SWS suitable for application in solar panels, displays, sensors, and other optoelectronic devices.

Initially reactive and concentrated generalized fluid wavy flow with the applications of disorder theory and magnetic field: A computational study

The wavy flow of generalized fluid namely, Cross fluid is mathematically formulated on a gravitationally affected vertical wavy surface with significant physical effects which is the main theme of this work. This particular dynamics of chemically reactive materials is further explored with an irreversible process. A significant heat transfer is measured through thermal resistance during the consideration of entropy optimization. Since entropy generation is associated with the mechanical systemenergy loss is more helpful in monitoring the entropy production in different engineering and industrial processes. Specifically, such irreversibility process appearance causing a noticeable low efficiency in the relevant practical sectors. For better performance in the minimization of friction on the wavy surface, flow is dissipated in terms of heat. However, the measure of loss in terms of work is introduced in the form of thermal radiation, viscous dissipation, magnetic field, and first-order chemical reaction. Additionally, the expected pressure drooping on the wavy surface is another goal of the entire study. The non-linear mathematical equations are determined by following the maximum viscosity approach. Relevant and important results are portrayed to show the various features of the newly developed work. The significant findings are approximated via one of the collocation methods while using MATLAB software. The Richardson number and buoyancy parameter enhanced the flow speed of the materials. The heat transfer rate is decreased by both Eckert number and wavy amplitude and the chemical reaction factor enhanced the mass transfer rate. The heat energy of the materials is escalated with the help of electromagnetic wave radiation and temperature ratio factor. Strengthening the chemical reaction factor declined the mass flow during the typical motion of the liquid. In the last, a comparison is provided to show the accuracy of the numerical approach.

Three-dimensional Darcy-forchheimer modelling of MHD hybrid nanofluid over rotating stretching/shrinking surface with Hamilton-Crosser and Yamada-Ota conductivity models

Instead of single nanoparticles, the combined effects of more than one solid nanoparticle have presented wide range of real-word application in several engineering as well as biomedical areas. The present analysis brings out a combined effect of Hamilton-Crosser and Yamada-Ota thermal conductivity models for the magnetohydrodynamic flow of hybridised fluid vi a rotating stretching/shrinking surface. The hybridised fluid comprised of silver and molybdenum tetrasulphide nanoparticle in association with the effect of Joule heating enriches the flow properties. Additionally, the Darcy-Forchheimer inertial drag with the impose of thermal radiation affecting the flow as well as heat transfer properties. The proposed mathematical model equipped with physical assumptions is transmuted into dimensionless form by utilizing similarity functions. Further, the traditional numerical technique is taken care of for the solution of the transmuted model equipped with diversified factors. The important characteristic of several factors are deployed graphically affecting various flow profiles. Finally, the outstanding features explored in the proposed investigation are stated as below; the comparative analysis reveals that, the heat transport properties became advanced in case of Hamilton-Crosser model rather than the Yamada-Ota conductivity model. However, the heat transportation rate is controlled by the increasing Eckert number but thermal radiation enhances it significantly.

Bioconvective magnetized flow analysis of a tangent hyperbolic nanofluid with nonuniform source/sink over an exponentially porous stretching sheet

AbstractThis study use numerical method to investigate the transportation of a bioconvective magnetized tangent hyperbolic nanofluid across an exponentially porous stretched sheet. The flow model takes into account the important contributions of Joule heating, thermal radiation, activation energy, and nonuniform heat source/sink. Moreover, slip boundary conditions with gyrotactic microorganisms are taken into flow analysis. The flow model is converted into a system of nonlinear ordinary differential equations (ODEs) using suitable similarity variables. The bvp4c approach in MATLAB is used to get numerical solutions for this system. The study evaluates the influence of different parameters on the velocity, temperature, concentration, and microorganism profile via graphical representations. The results indicate that increasing the mixed convection parameters accelerates the velocity profile, whereas raising the magnetic parameter slows it down. The temperature profile increases with higher values of radiation parameter, however, it decreases as the Prandtl number and thermal slip parameter increase. Furthermore, the microorganism profile decreases as the bioconvection Lewis number and microorganism slip parameter increase.

Boost heat transfer efficiency through thermal radiation and electrical conductivity in nanofluids

AbstractThermal radiation and electrical conductivity in nanofluids are crucial for their heat transfer characteristics, especially in applications with elevated temperatures or significant radiative heat transfer. The suspension of nanoparticles in suspension contributes to the fluid's electrical conductivity, which is essential for efficient heat dissipation in electronic cooling systems. Understanding the behavior of electroconductive nanofluids is particularly important in electronic cooling applications, where effective heat dissipation is crucial to prevent overheating. A study using a similarity parameter transformed a system of coupled PDEs into a set of nonlinear ordinary differential equations, revealing significant changes in key physical characteristics, such as temperature distribution, cubic concentration field, and velocity field. The study also examined the effects of parameters like Brownian motion, Rayleigh number, Peclet number, thermophoresis parameter, and buoyancy ratio parameter. The research provides valuable insights into the complex dynamics of magnetized non‐Newtonian nanofluids and offers practical implications for applications like microbial fuel cells and heat transmission equipment.

Study of MHD Casson Nanofluid Flow Over an Inclined Stretching Sheet in Porous Media with Thermal Slip, Chemical Reaction and Radiation Effects

In the current study, the behaviour of Casson nanofluid subjected to magnetohydrodynamic (MHD) flow across an inclined stretched sheet within a porous medium has been investigated numerically. The governing equations are transformed into ordinary differential equations with the corresponding boundary conditions by employing similarity transformations. The solutions of essential equations are achieved by using the 4th-order Runge-Kutta method combined with the shooting technique. The novelty and innovative contribution are showcased through illustrative graphs that scrutinize the effect of factors that impact the velocity, temperature, and concentration profiles within assorted flow scenarios. The primary focal points of the study encompass examining variations in magnetic field strength, angle of inclination, and suction intensity that affect the fluid's velocity moderation, while improved porosity and radiation parameters lead to a rise in fluid temperature. Higher Biot numbers correlate with an increase in fluid temperature. The implications of positive coefficients of heat transfer are crucial across various fields to ensure efficient thermal management ensuring optimal performance and longevity. The numerical data presented is aligned with earlier published results for comparison. Furthermore, the variations in skin friction, Nusselt, and Sherwood numbers driven by different parameters are displayed in tables to highlight significant modifications.

ЧИСЛЕННАЯ МОДЕЛЬ СВОБОДНОЙ КОНВЕКЦИИ В ПРОСТРАНСТВЕ ЭКРАННО-ВАКУУМНОЙ ИЗОЛЯЦИИ ПРИ ТЕПЛОВОМ ВОЗДЕЙСТВИИ ПОЖАРА

The objective of the study is to find the patterns of the conjugate heat transfer process in a closed space of a coaxial cylinder’s pair under the influence of an external source of thermal radiation within the framework of the free convection model. It is assumed that the priority type of heat transfer in the gas filling the coaxial space is turbulent free convection, and thermal conductivity in the external thermal insulation of the pipeline. A model of the free convection process in a coaxial gas cavity in the presence of local heating in the form of a system of differential equations is created. Comparative results of a full-scale and numerical experiment on measuring the effective coefficient of thermal conductivity of screen-vacuum insulation are presented.

Combustion efficiency analysis and thermal radiation risk quantification for spill fire in sealed ship cabin

In this study, the authors conducted a series of one-dimensional spill fire experiments in a sealed model-scale ship cabin with different leakage rates to reveal the combustion characteristics. The results showed that a stable combustion stage with a consistent combustion area and flame height appears around the cut-off of the fuel, where the consumption of oxygen increases when the leakage rate increases. And the CO2 concentration increases more rapidly and the upward trend is found to appear earlier. Compared with the film thickness in the open space, that of the spill fire in the sealed ship cabin is slightly thinner because of the ventilation control effect. Using the “oxygen-consumption” method, the η of this stage was calculated and verified with the “mass loss rate” method. With these two methods, the HRR of spill fie when burning steadily is calculated. This work also improved the predicting model for the flame height of rectangular pool fire and developed a predicting model for the flame height of a steadily burning spill fire. The error is 14.35 %. Additionally, a predictive model of thermal radiation risk in ship spill fire is developed, and the death risk and unacceptable risk areas are delimited.