One-dimensional Mathematical Model Research Articles

Kinetic modeling and reaction mechanism of toluene and by-products in photocatalytic oxidation reactor

Photocatalytic oxidation (PCO) is an innovative and promising technology for removing VOCs from indoor environment. However, partial oxidation of reactants generates by-products that could be more harmful to human health than parent compound. This paper presents the development of a by-products predictive model for the estimation of generated by-products based on the degradation reaction pathway of toluene in PCO. A one-dimensional mathematical model by considering the axially dispersed plug flow and Langmuir-Hinshelwood (L-H)-based reaction rate as well as linear source spherical emission (LSSE) model for the irradiation distribution on the media surface was developed for the prediction of the by-products concentration. Toluene was tested in a continuous flow PCO reactor with a commercial PCO filter under various operating conditions; concentrations (0.05–1 ppm), relative humidities (17–67%), flow rates (10–30 L/min), and irradiance (7–23.5 W/m2). Several by-products from various chemical groups, including aldehyde, ketone, alcohol and light acid, were identified by analytical instruments. Aldehydes were the major by-products of toluene in PCO, in which light aldehydes (acetaldehyde and formaldehyde) had a higher concentration among others. The result of curve fitting using the proposed model showed a high accuracy of the model (with R-squared greater than 0.98) for parameters estimation. Kinetic analysis of toluene indicated that the rate coefficients followed the order of benzaldehyde > propionaldehyde > acetaldehyde > formaldehyde. Benzaldehyde and propionaldehyde had a greater value of the kinetic coefficient in PCO because of higher adsorption tendency towards TiO2. Changes in operating conditions highly affected generation of by-products and the developed model could predict the concentration of toluene and the by-products with acceptable accuracy. The carbon balance analysis at residence time of 0.24 s showed 16.6% of toluene mineralized into carbon dioxide and it increased at longer residence time. The health risk index (HRI) analysis of toluene and its by-products was performed and found out that formaldehyde was the most influential pollutant on HRI due to very low recommended exposure limit and higher generated concentration.

Countering reproducibility issues in mathematical models with software engineering techniques: A case study using a one-dimensional mathematical model of the atrioventricular node.

One should assume that in silico experiments in systems biology are less susceptible to reproducibility issues than their wet-lab counterparts, because they are free from natural biological variations and their environment can be fully controlled. However, recent studies show that only half of the published mathematical models of biological systems can be reproduced without substantial effort. In this article we examine the potential causes for failed or cumbersome reproductions in a case study of a one-dimensional mathematical model of the atrioventricular node, which took us four months to reproduce. The model demonstrates that even otherwise rigorous studies can be hard to reproduce due to missing information, errors in equations and parameters, a lack in available data files, non-executable code, missing or incomplete experiment protocols, and missing rationales behind equations. Many of these issues seem similar to problems that have been solved in software engineering using techniques such as unit testing, regression tests, continuous integration, version control, archival services, and a thorough modular design with extensive documentation. Applying these techniques, we reimplement the examined model using the modeling language Modelica. The resulting workflow is independent of the model and can be translated to SBML, CellML, and other languages. It guarantees methods reproducibility by executing automated tests in a virtual machine on a server that is physically separated from the development environment. Additionally, it facilitates results reproducibility, because the model is more understandable and because the complete model code, experiment protocols, and simulation data are published and can be accessed in the exact version that was used in this article. We found the additional design and documentation effort well justified, even just considering the immediate benefits during development such as easier and faster debugging, increased understandability of equations, and a reduced requirement for looking up details from the literature.

A model for predicting the lateral distribution of sediment transport in river bends

ABSTRACT Distribution of lateral velocity and suspended sediment concentration in river bends is highly non-uniform. Predicting such velocity and sediment distributions is prerequisite for many applications, such as river bank protection, sediment transport, deposition pattern, pollutant transport and flood control. Due to secondary flow development, flow structure in river bends has three-dimensional feature. In this case, one-dimensional mathematical models are generally not suitable, so two- or three-dimensional mathematical models have to be used. In this paper, field measurement of lateral distributions of flow velocity and suspended sediment concentration was conducted in three bends at the Karun River in Iran (namely, Jangieh, Khabineh and Malheh), and the measured velocity data were used for calibrating the Spooner and Shiono model. Based on the lateral velocity distributions by this mathematical model, sediment transport capacities were computed using five commonly used empirical formulas of sediment transport. The results showed that in the three river bends, the sediment transports formula by Yang agrees well with the measured lateral sediment concentration. The Van Rijn formula also predicts the results with suitable accuracy. The other three formulas by Ackers-White, Engelund-Hansen, and Karim-Kennedy significantly over-predict the sediment concentration compared with the measured data.

A suitability analysis of transient one-dimensional two-fluid numerical models for simulating two-phase gas-liquid flows based on benchmark problems

Gas-liquid two-phase flows in pipes are present in a variety of engineering applications. These applications require transient one-dimensional mathematical models coupled with robust numerical methods to simulate the flow behavior in time and space. As there exist several possible combinations of models and numerical methods, questions arise as to the suitability of these numerical models to best accommodate the problem features. Aiming to partially answer this question, we present in this work numerical simulations of two well-known gas-liquid benchmarks, the water faucet, and the shock tube problems, carried out with two two-fluid models – 4E1P (four equations and one pressure) and 5E2P (five equations and two pressures) – in association with three numerical methods – FCT (Flux-Corrected Transport method), FORCE (First-Order Centered Scheme) and ModFORCE. The numerical methods used herein are written in a general form and do not require the solution of the associated Riemann problem. The obtained results are sought to serve as a reference to choose the best approaches, among the ones studied, to tackle some transient one-dimensional two-phase flow problems, highlighting the advantages and disadvantages of each model and method combination regarding hyperbolicity, diffusive and dispersive effects. Overall, the combination of the 5E2P model with the ModFORCE numerical method provides the most accurate results compared to the analytical solutions available.

Simplified mathematical model and experimental analysis of latent thermal energy storage for concentrated solar power plants

Depletion of fossil reserves and environmental concerns arising from their use has led to the development of renewable energy technologies. Concentrated solar power (CSP) is one of the promising alternative energy solutions that can be built in higher capacity (hundreds of megawatts) and provide higher thermal efficiencies compared to other technologies. However, almost all CSP systems require thermal energy storage (TES) to improve the capacity factor and bridge the gap between supply and demand. In the current work, a reduced-order one-dimensional mathematical model of a phase change material (PCM) based TES is proposed and experimentally validated on different sets of data including different PCM, operating ranges and storage size per geometrical unit of the CSP. The model considers single EPCM as a lumped thermal mass without much compromise on the accuracy having less than 9% overall error in terms of predicting energy storage capacity when compared to experimental data. Additionally, an experimental setup for encapsulated-PCM (EPCM) is developed using NaNO3-KNO3 as the PCM. This system has a storage capacity of 9.7 MJ and a storage time of 6 hours is required to completely charge the system at selected conditions. An analysis of the system performance is presented under different experimental conditions. The model development, experimental analysis and validation shall provide reliable design estimates while designing EPCM-TES for large-scale applications. Therefore, the current simplified mathematical model best fits such applications where a design engineer needs to make quick decisions regarding the selection of an EPCM-TES system or where a reduced-order model of entire CSP plant is required.

Performance analysis of hydrogen iodide decomposition membrane reactor under different sweep modes

Hydrogen iodide decomposition is the core hydrogen production step in the sulfur-iodine thermochemical cycle, which determines the hydrogen production rate and thermal efficiency of the device. The conventional decomposition reactor is limited by equilibrium conditions, so the hydrogen iodide conversion rate is low at normal reaction temperature, and membrane reactor technology can break the limit of equilibrium condition and greatly improve the conversion rate. Most of the previous hydrogen iodide membrane reactor models were built under isothermal conditions and did not consider the influence of different sweep modes. In this paper, a one-dimensional non-isothermal hydrogen iodide decomposition membrane reactor mathematical model in co-current and countercurrent sweep modes is established, and the effects of reactor parameter on hydrogen iodide conversion and hydrogen recovery rate are analyzed under the two sweep modes. The results show that the countercurrent mode can obtain higher hydrogen iodide conversion rate than the co-current mode under larger sweep flow rate, inlet pressure of reaction and permeation zone, reactor length; the maximum recovery rate of hydrogen in countercurrent mode is close to 100%. A modified membrane reactor structure combining the traditional reactor and membrane reactor is proposed, which could effectively increase the hydrogen permeation flux per unit membrane surface. In engineering application, the reasonable design of the modified membrane reactor can effectively reduce the investment cost of the membrane reactor on the premise of satisfying the hydrogen production rate.

Trefftz Method of Solving a 1D Coupled Thermoelasticity Problem for One- and Two-Layered Media

This paper discusses a 1D one-dimensional mathematical model for the thermoelasticity problem in a two-layer plate. Basic equations in dimensionless form contain both temperature and displacement. General solutions of homogeneous equations (displacement and temperature equations) are assumed to be a linear combination of Trefftz functions. Particular solutions of these equations are then expressed with appropriately constructed sums of derivatives of general solutions. Next, the inverse operators to those appearing in homogeneous equations are defined and applied to the right-hand sides of inhomogeneous equations. Thus, two systems of functions are obtained, satisfying strictly a fully coupled system of equations. To determine the unknown coefficients of these linear combinations, a functional is constructed that describes the error of meeting the initial and boundary conditions by approximate solutions. The minimization of the functional leads to an approximate solution to the problem under consideration. The solutions for one layer and for a two-layer plate are graphically presented and analyzed, illustrating the possible application of the method. Our results show that increasing the number of Trefftz functions leads to the reduction of differences between successive approximations.

Analysis of dynamic performance in a pump-turbine during the successive load rejection

Successive load rejection is one of the most crucial transient processes for calculating the maximum pressure in spiral case and maximum rotating speed of runner. One-dimensional mathematical models were established for a pump-storage power station and characteristics method was used to study the successive load rejection. The condition in which the maximum pressure occurs was chosen for three-dimensional unsteady calculation. The boundary conditions at spiral-casing inlet and draft tube outlet were determined by using the one-dimensional result. Based on numerical simulation, the axial hydraulic thrust and transient flow characteristic during the successive load rejection process were analysed. The axial hydraulic thrust during the successive load rejection process was mainly caused by the complex flow in the runner. The complex flow was affected both by hydraulic disturbance and the successive load rejection process.

Pressure Loss Due to Hydraulic Transport of Large Solid Particles in Vertical Pipes Under Pulsating Flow Conditions

Abstract It is important to predict the pressure loss due to hydraulic transport of large solid particles for the design of subsea mining system. The mixture flow in the lifting pipe is expected to be unsteady in the actual mining system. The authors develop the one-dimensional mathematical model to predict the pressure loss of pulsating mixture flow in a static vertical pipe assuming that the flow in the pipe is fully developed. The experiment on hydraulic transport of solid particles was carried out to obtain the data for the investigation of the effects of flow fluctuation on pressure loss in a static vertical pipe. In the experiment, alumina beads and glass beads were used as solid particles, and the experimental parameters were mixture velocity, solid concentration, pulsating period, and pulsating amplitude. The proposed model was validated by a comparison with experimental data. Furthermore, we calculated the pressure losses due to hydraulic transports of polymetallic sulfide ores and manganese nodules using the proposed model. The calculation results showed that the fluctuating component in pulsating mixture flow should be considered for the design of lifting system and that the homogeneous mixture model could not be applied to the prediction of the pressure loss unless the mixture concentration is low and the pulsating period is short.

Pressure drop in two phase flow of condensing air-steam mixture inside PHE channels formed by plates with corrugations of different geometries

The pressure drop in the two-phase condensing flow of air-steam mixture inside channels of plate heat exchanger (PHE) with different geometries of corrugations is studied based on experiments and one-dimensional mathematical modelling. The experiments were made with five samples of the PHE channel. In three of them plates with corrugations inclination angles 30, 45 and 60° at the same height of corrugations 5 mm. The other two plates corrugations height was 7.5 and 10 mm at the same pitch to height ratio and inclination angle of 60°. The correlation of pressure drop data for all experimental samples by average process parameters is not able to give acceptable accuracy. The correlation for local pressure gradients in two-phase condensing flow is identified using a developed one-dimensional mathematical model. The model of separated flows of phases is employed for channel zones close to air-steam mixture entrance. Further on channel length with an increase of liquid phase quantities, its combination with the dispersed annular flow structure model is used. The proposed equations can be included in the mathematical model when designing PHE and optimising the geometrical form of corrugations on its plates for steam condensation processes from an air-steam mixture.

Analytical solutions for the incompressible laminar pipe flow rapidly subjected to the arbitrary change in the flow rate

A one-dimensional mathematical model is developed for an unsteady incompressible laminar flow in a circular pipe subjected to a rapid change in the flow rate from an initial flow with flow rate, Qi, to a final flow with flow rate, Qf, in a step-like fashion at an arbitrary time, tc. The change in the flow rate may either be an increment, Qf > Qi, or a decrement, Qf < Qi. The change time, tc, may either belong to the initial flow remaining in a temporally developing state or temporally developed state. The developed model is solved using the Laplace transform method to deduce generalized analytical expressions for the flow characteristics, viz., velocity, pressure gradient, wall shear stress, and skin friction factor, CfRe, where Re is Reynolds number based on the cross-sectional area-averaged velocity and pipe radius. Exact solutions for λa=Qi/Qf=0 and λd=Qf/Qi=0 with tc≥tsi are available in the literature and the present generalized analytical solutions fill the remaining range of parameters, 0<λa<1 and 0<λd<1 with 0<tc<tsi and tc≥tsi, where tsi is the time at which the initial flow reaches the temporally developed state. Exact solutions for canonical pipe flow problems reported in the literature are deduced as subsets of the derived generalized solutions. The parametric study reveals the effects of varying λa or λd and tc on the quantities of practical importance, viz., τs and CfRe, where τs is the time required for the final flow to reach the temporally developed state.

Water Quality Improvement Effective Analysis for Artificial Groundwater Recharge in Urban River Network System

With increase of population and urbanization, the persistent deterioration of urban rivers has become the most intractable problem for environment management agency. After the boom of pollution control projects implementing such as sewage system and sewage treatment plants building to decrease the pollution load, there is a growing interest on increasing ground water discharge with artificial groundwater recharge work and improving load capacity of target river. Under this background, it is important to study the exact effect of water artificial groundwater recharge work on water quality improvement, especially in the river network area, to give support on exact designment. In this study, the river network in Hanjiang district featured with complex river network has been selected as study area. Based on water quality monitoring result and current load statistical result, a one-dimensional mathematic model of target river network has been set up and the water quality has been simulated with different water artificial groundwater recharge schemes, which considering both river supplementary discharge and water quality factors. Then the simulation results under different effects have been analysed and the optimal scheme has been selected to meet the goals. The analysis results indicate that qualified option is recharging 2 m3/s fresh water of level III, under which, the water quality of study area can achieve the basic standard of Level V as qualified scenic water.

Modeling Simulation and Validation of a Tractor Wet Clutch Controlled by Proportional Valve

Wet clutch is a widely used machine element in the agricultural machines be-cause it allows the transmission of high torque with a more user-friendly turn on/off. In this article, the control of a wet clutch pack using a proportional valve in the power take-off unit is investigated. A wet clutch package is implemented on the transmission direct PTO shaft and actuate the power take-off unit of an ag-ricultural tractor. A one-dimensional mathematical model of the wet clutch and the electro-hydraulic control system was developed. Several actuation cases were simulated, and responses of all circuit elements were evaluated. Based on these predictions, test procedures with out-put torque values 300 and 600 N-m were set at 1.900 rpm unloaded engine speed. Variables, including speed, pres-sure, and temperature, were recorded in the experiments. The test and simulation results were compared. The clutch pressure increase was 10% under-predicted while the mainline pressure drop was 1% over-predicted. The proposed 1-D model can be further improved indeed. Yet, the acceptable agreement between the model and tests, offer less costly trial-and-error in the design and tune-up of future systems.

A method of determining leaks transported liquid from the pipeline

The problem of detecting leaks of oil and petroleum products from the pipeline is considered. For the mathematical description of the problem we use one-dimensional mathematical model of unsteady flow of a viscous incompressible fluid in pipeline, which includes the equation of motion and equation of continuity of fluid flow. In this case, the liquid leak is represented as a point drain described by the Delta function, and the continuity equation is compiled taking into account the point drain. The pressure and volume flow of the liquid in the initial and final sections of the pipeline are considered set. Taking into account the features of point runoff, the task is split into two tasks with matching conditions. Analytical solutions to the obtained problems are determined and explicit formulas are derived for determining the volume flow rate of the liquid for leakage and the coordinates of the leak location in the pipeline.

Words high-frequency drying processes simulation of wooden tangent towers in a vacuum chamber

THE PURPOSE. The service life duration of wooden tangent towers used on overhead transmission lines with a voltage of up to 35 kV depends on the quality of lumber drying and subsequent impregnation. The drying of tangent tower workpieces is currently carried out by atmospheric or convective methods and is the longest and one of the energy-consuming stages of their production. At the same time, there are promising electrotechnological drying installations that can reduce the duration and improve drying quality at comparable specific energy costs. Such installations include vacuum high-frequency complexes, the wide introduction of which is complicated by a number of unresolved scientific and technical problems like optimizing vacuum high-frequency drying modes and ensuring electromagnetic field uniformity in long workpieces. The purpose of this article is to obtain mathematical tools that simultaneously describe the cross-effects of electromagnetic phenomena and heat and mass transfer processes in long-sized lumber and contribute to the further solution of these problems. METHODS. The positions of the theory of electromagnetic field, heat mass transfer and heat mass exchange, methods of mathematical modeling were used for this purpose. Also the results of previous studies of electromagnetic field distribution in the cross-section and longitudinal sections of the working chamber loading are taken into account. RESULTS. А one-dimensional mathematical model is obtained. It describes the influence of electromagnetic wave distribution along the length of tangent towers and external medium parameters on the temperature and moisture content in the material. This model is characterized by the possibility of using simple algorithms for analyzing differential equation systems based on the finite differe nce method and requiring less initial data on the drying material properties. CONCLUSION. The obtained by using the proposed model and the method of its analysis the numerical study results are compared with the available experimental data. Based on this comparison it is concluded that the obtained model is adequate and more effective relative to other existing models of vacuum high-frequency drying. Generally, further use of the presented mathematical toolkit to optimize the design and modes of vacuum-high-frequency complexes in the task of drying wooden tangent towers will increase the reliability of overhead transmission lines.

A Shoreline Evolution Model with a Groin Structure under Non-Uniform Breaking Wave Crest Impact

Beach erosion is a natural phenomenon that is not compensated by depositing fresh material on the shoreline while transporting sand away from the shoreline. There are three phenomena that have a serious influence on the coastal structure, such as increases in flooding, accretion, and water levels. In addition, the prediction of coastal evolution is used to investigate the topography of the beach. In this research, we present a one-dimensional mathematical model of shoreline evolution, and the parameters that influence this model are described on a monthly basis over a period of one year. Consideration is given to the wave crest impact model for evaluating the impact of the wave crest at that stage. It focuses on the evolution of the shoreline in environments where groins are installed on both sides. The initial and boundary condition setting techniques are proposed by the groins and their environmental parameters. The non-uniform influence of the crest of the breaking wave is so often considered. We then used the traditional forward time centered space technique and the Saulyev finite difference technique to estimate the monthly evolution of the shoreline for each year.

Modelling the effect of sinter machine speed on bed temperature and coke combustion characteristics in iron ore sintering process

ABSTRACT In the present study, the influence of industrial sinter machine speed on the temperature distribution of the bed is evaluated using a one-dimensional transient mathematical model. The model is developed considering the law of conservation of mass, momentum, and energy of solid and gas phases. The prediction of bed temperature from the model is compared with the measured lab scale pot test and the exit gas temperature of an industrial sinter machine wind boxes shows a reliable agreement. The effect of machine speed on the temperature of the bed is quantified using Maximum Temperature, and the coke combustion characteristics are expressed in terms of Duration Time of Coke Combustion and Combustion Zone Thickness. Eventually, the Melting Zone Thickness and melt fraction of the bed is evaluated. This model result demonstrates that the increasing industrial sinter machine speed significantly affects the temperature distribution of the top layer of the sinter bed.

Iterative method for solving one-dimensional fractional mathematical physics model via quarter-sweep and PAOR

This paper will solve one of the fractional mathematical physics models, a one-dimensional time-fractional differential equation, by utilizing the second-order quarter-sweep finite-difference scheme and the preconditioned accelerated over-relaxation method. The proposed numerical method offers an efficient solution to the time-fractional differential equation by applying the computational complexity reduction approach by the quarter-sweep technique. The finite-difference approximation equation will be formulated based on the Caputo’s time-fractional derivative and quarter-sweep central difference in space. The developed approximation equation generates a linear system on a large scale and has sparse coefficients. With the quarter-sweep technique and the preconditioned iterative method, computing the time-fractional differential equation solutions can be more efficient in terms of the number of iterations and computation time. The quarter-sweep computes a quarter of the total mesh points using the preconditioned iterative method while maintaining the solutions’ accuracy. A numerical example will demonstrate the efficiency of the proposed quarter-sweep preconditioned accelerated over-relaxation method against the half-sweep preconditioned accelerated over-relaxation, and the full-sweep preconditioned accelerated over-relaxation methods. The numerical finding showed that the quarter-sweep finite difference scheme and preconditioned accelerated over-relaxation method can serve as an efficient numerical method to solve fractional differential equations.

Denitrification Modeling using Natural Organic Solid Substrates as Carbon Sources

En los últimos años, se han estudiado Sustratos Sólidos Orgánicos Naturales (SSON) como fuentes de carbono económicas y seguras, para su uso en la desnitrificación del agua. Aunque los resultados de desnitrificación con SSON han sido satisfactorios, aún es limitada la información de los procesos que intervienen en la interfaz SSON-biopelícula. Con el objetivo de comprender dichos procesos, desarrollamos un modelo matemático unidimensional de desnitrificación en contragradiente, con el cual evaluamos: el comportamiento de la biopelícula adherida al SSON y su efecto en la liberación del carbono; transporte y consumo de carbono, transporte y consumo de nitrato. Para tal fin, se usó Saccharum Spontaneum L. como SSON de referencia, de la cual se tienen parámetros biocinéticos y de hidrólisis generados en estudios previos de desnitrificación. En este artículo se presentan los resultados de la modelación matemática de desnitrificación, con SSON como fuentes de carbono, lo cual se simuló con el programa AQUASIM. Los supuestos y simplificaciones definidas permitieron predecir teóricamente la desnitrificación en reactores batch y completamente mezclado con flujo. Las mejores simulaciones del estudio se obtuvieron en condiciones con desprendimiento de biopelícula, donde la desnitrificación fue superior al 80%. Los parámetros más significativos de esta modelación matemática fueron el rendimiento neto de bacterias (Yh) y la hidrólisis (kh). Estos hallazgos demuestran la importancia de plantear modelos conceptuales y matemáticos de desnitrificación usando SSON. Este estudio sería una primera aproximación de un modelo matemático de desnitrificación en contragradiente, usando a los SSON como fuente de carbono y portador de biopelícula.

Effective heat conductivity of Honeycomb (porous) composite panel

PurposeThe purpose of this paper is to validate an assumption of what to use as an effective (steady state) heat transfer coefficient of thermal conductivity for the honeycomb core sandwiched by Fiberglass face sheets composite. A one-dimensional model based on Fourier law is developed. The results are validated experimentally.Design/methodology/approachThe results were obtained from the one-dimensional mathematical model of an overall or effective heat conductivity of the Honeycomb composite panel. These results were validated experimentally by applying heat flux on the specimen under controlled environment. The surface temperatures at different voltages were recorded and analysed. The skin of the sandwich composite material used in the investigation was Fiberglass sheet with a thickness of 0.5 mm at the bottom and 1.0 mm at the top surface. Both skins have a stacking sequence of zero degrees. Due to the presence of air cells in the core (Honeycomb), the model considers the conduction, convection and radiation heat transfer, across the thickness of the panel, combined as an effective conduction mode, whose value may be predicted by using the coefficient of thermal conductivity of the air based on the average temperature difference between the two skins. The experimental results for the heat transfer through the thickness of the panel provide validation of this assumption/prediction. Both infrared thermography and conventional temperature measurement techniques (thermocouples) were used to collect the data.FindingsThe heat transfer experiment and mathematical modeling were conducted. The data obtained were analyzed, and it was found that the effective thermal conductivity was temperature-dependent as expected. The effective thermal conductivity of the honeycomb panel was close to that of air, and its value could be predicted if the panel surface temperatures were known. It was also found that as temperature raised the variation between experimental and predicted effective air conduction raised up. This is because there was an increase in molecular diffusion and vibration. Therefore, the convection heat transfer increased at high temperatures and the air became an insulator.Originality/valueHoneycomb composite panels have excellent physical and thermal properties that influence their performance. This study provides an appropriate method in determining thermal conductivity, which is one of the critical thermal properties of porous composite material. This paper also gives useful and practical data to industries that use or manufacture honeycomb composite panels.