Rectangular Volume Research Articles

Transverse resonance technique for analysis of a symmetrical open stub in a microstrip transmission line

Open stubs in a strip (microstrip) transmission line are one of the most common elements of planar circuits used in numerous devices in the various types of wireless systems. Therefore, the urgent problem is to develop an analyzing method for discontinuities in the form of the open stub in a microstrip transmission line at frequencies at which the high-frequency effects must be considered. In the paper, a technique of scattering characteristics calculating on a symmetrical microstrip open stub by transverse resonance method is presented. Boundary value problems for a rectangular volume resonator based on a microstrip transmission line with a symmetric open stub are solved for the three options boundary conditions in the symmetry plane and on the longitudinal boundaries. The intersection of the spectral curves obtained by the numerical solution of the “electric” and “magnetic” boundary value problems determines the minima of a reflection or transmission coefficients of fundamental wave on discontinuities. To algebraize the boundary value problems for the eigen frequencies of volume resonator with discontinuity, the corresponding two-dimensional functions of the magnetic potential are constructed, through which the components of the current density on the strip are determined. The functions of magnetic potential were defined by decomposing them into expansion by Fourier series, which ensures stable convergence of the series and numerical calculation algorithm. The developed technique has been tested by calculating the eigenfrequency spectra of an open microstrip stub using the transverse resonance method on the example of an open stub in a microstrip transmission line with a resonant frequency of about 3.0 GHz. Also, a technique for numerical solutions of “electric” and “magnetic” boundary-value problems for resonators with two electrodynamically coupled symmetric open stubs in a microstrip transmission line is developed.

An Improved One-Line Evolution Formulation for the Dynamic Shoreline Planforms of Embayed Beaches

In this paper, an improved one-line evolution formulation is proposed and derived for the dynamic shoreline planforms of embayed beaches. Although embayed sandy beaches can perform several functions, serving as leisure spots and areas of coastal protection, shoreline advances and retreats occur continuously as a result of many natural forces, such as winds, waves, currents, tides, etc. The one-line evolution formulation for dynamic shoreline planforms based on the polar coordinate can be adopted to simulate high-planform-curvature shorelines and achieve better stability and simplicity in comparison with other description coordinates. While the polar coordinate and rectangular control volume are adopted to derive the one-line evolution formulation for dynamic shoreline planforms, the difference between the radial direction of the polar coordinate and the normal direction of the shoreline segment may result in inaccurate predictions of shoreline movements. In this study, a correction coefficient, which can adjust the influence of these two misaligned directions, is derived and included in the one-line evolution formulation, which is based on the polar coordinate. Thus, by considering the correction coefficient, an improved one-line evolution formulation for dynamic shoreline planforms of crenulate-shaped bays is proposed in this paper. Some numerical examples are provided to verify the merits of the proposed improved one-line evolution formulation. Moreover, the proposed numerical approach is applied to simulate the dynamic movements of the shoreline in Taitung—the southeastern part of Taiwan—and the effectiveness of the proposed formulation in solving realistic engineering applications is evidently verified.

Application of immersed boundary method to the simulation of three-dimensional flow in solid rocket motors

The immersed boundary method (IBM) is currently utilized in the simulation of two-dimensional axisymmetric flow in solid rocket motors. In this paper, the IBM is applied to three-dimensional flow fields, keeping the grain surface fixed. Based on the Cartesian grid, a three-dimensional Euler flow solver is developed using the finite difference method. All boundaries of the flow field are processed using the IBM, including the slip walls, mass flow inlet, pressure outlet, and rotational periodic boundary. Specific implementation of these boundary conditions and the mesh generation process are described. Using the ray-casting approach and the alternating digital tree data structure, an efficient method is proposed to determine the intersection relationship between a rectangular volume grid cell and a triangular surface mesh element. The numerical results of Taylor–Culick flow verify that the developed solver has more than one-order accuracy in space. To conduct the validation of the established method, three typical grains are selected for flow simulations, namely, the perforated cylindrical grain with burning on both the ends and the inner surface, the end-slotted end-burning grain, and the finocyl grain, respectively. The simulated results are compared with those of the zero-dimensional interior ballistics, the two-dimensional axisymmetric IBM, and the body-fitted grid method, verifying the fidelity of the developed three-dimensional flow solver.

Structure–function assessment in glaucoma based on perimetric sensitivity and en face optical coherence tomography images of retinal nerve fiber bundles

Many studies have assessed structure–function relations in glaucoma, but most without topographical comparison across the central 30°. We present a method for assessing structure–function relations with en face images of retinal nerve fiber layer (RNFL) bundles allowing topographical comparison across much of this retinal area. Forty-four patients with glaucoma (median age 61 years) were recruited and tested with Optical Coherence Tomography (OCT) and perimetry. Six rectangular volume scans were gathered, and then montaged to provide en face views of the RNFL bundles. We calculated the proportion of locations showing a perimetric defect that also showed an en face RNFL defect; and the proportion of locations falling on an RNFL defect that also showed a perimetric defect. A perimetric defect for a location was defined as a total deviation (TD) value equal to or deeper than -4 dB. We found that the median (IQR) number of locations with abnormal RNFL bundle reflectance that also had abnormal TD was 78% (60%) and for locations with abnormal TD that also had abnormal RNFL bundle reflectance was 75% (44%). We demonstrated a potential approach for structure–function assessment in glaucoma by presenting a topographic reflectance map, confirming results of previous studies and including larger retinal regions.

Probing Deep Lung Regions using a New 6-electrode Tetrapolar Impedance Method.

Probing deep regions of the lung using electrical impedance is very important considering the need for a low cost and simple technique, particularly for the low and medium income countries. Because of complexity and cost, Electrical Impedance Tomography is not suitable for this envisaged application. The simple Tetrapolar Impedance Measurement (TPIM) technique employing four electrodes is the age old technique for bioelectrical measurements. However, it has its limitations in respect of organ localisation and depth sensitivity using skin surface electrodes. Recently, a new 6-electrode TPIM with two current electrodes but two pairs of appropriately connected potential electrodes positioned on the front and back of the thorax, proposed by one of the authors, came with a promise. However, this work gave a qualitative proposal based on concepts of physics and lacked a quantitative evaluation. In order to evaluate the method quantitatively, the present work employed finite element method based COMSOL Multiphysics software and carried out simulation studies using this new 6-electrode TPIM and compared the results with those from 4-electrode TPIM, with electrodes applied either on the front or at the back of the thorax for the latter. Initially, it carried out a sensitivity distribution study using a simple rectangular volume conductor which showed that the 6-electrode TPIM gives better depth sensitivity throughout the lung region. Next it used a near life like thorax model developed by another of the authors earlier. Using this model, extensive studies were carried out to quantify the overall sensitivity over a target lung region, the contribution of the target lung to the total measured impedance, and several other parameters. Through these studies, the 6-electrode TPIM was established on a stronger footing for probing deep regions of the lungs.

Improving Deep Sensitivity of Four-Electrode Focused Impedance Method In Lungs by Varying Electrode Geometries

Bio-Electrical impedance is of special interest in the detection and diagnosis of lung problems, particularly in the low and medium income countries. An age old simple technique employing four electrodes is known as ‘Tetra Polar Impedance Measurement (TPIM)’ but it cannot localize a particular zone of interest region. A new technique named as ‘Focused Impedance Method (FIM)’ was innovated by a Dhaka University group which gives high sensitivity in a localized zone of interest. Previously FIM was used from one side of the thorax which gave a rather limited information from the lungs, from shallow depths only. In order to get information from deeper regions of the lungs a new configuration of electrodes for FIM was proposed by the same group at Dhaka University which placed two electrodes at the front and two electrodes at the back of the thorax in a horizontal plane. It is expected that the degree of depth sensitivity would depend on electrode separation on both the sides. The electrode width may also have an effect. In order to study these quantitatively, COMSOL Multiphysics software was used to simulate the measurements in a rounded rectangular volume to represent a typical thorax, which was filled with isotonic saline. Electrode separations of 5cm, 10cm, 15cm and 20cm were studied while electrode widths studied were 0.15cm, 1cm and 3cm. The work supported the proposed new configuration of electrodes for FIM in that this method gives enhanced sensitivity throughout the depths of a lung and that for a thorax with a cross section of 33cm26cm, an electrode separation between 10cm and 15cm would give optimum results. For electrode width, the ones studied did not give any significant difference, however, the smallest (0.15cm) one appeared to give slightly better results.
 Bangladesh Journal of Medical Physics Vol.15 No.1 2022 P 43-54

Performance of a horizontal well in a bounded anisotropic reservoir: Part I: Mathematical analysis

Abstract To enhance the productivity of horizontal wells, it is of necessity to ensure that they perform optimally. This requires an understanding of how the reservoir’s geometry, anisotropy and well design affect the pressure response. Mathematical formulations can be used to simulate pressure response in the wellbore and the data obtained can be analysed to obtain well and reservoir parameters that can aid performance and evaluation. In this study, a mathematical model that can be used to approximate pressure response in a horizontal well is formulated, and a detailed mathematical analysis that can be used to obtain well and reservoir parameters are provided. A horizontal well inside a rectangular drainage volume with sealed boundaries is considered and the effect of each boundary on pressure throughout its productive life is studied. In the analysis, investigations on how the reservoir parameters can be approximated over a given period of production are conducted. This is achieved by identification of the appropriate source and Green’s functions. These source functions allow us to formulate a mathematical model for dimensionless pressure. Considering the diagnostic plots for both dimensionless pressure and dimensionless pressure derivative, mathematical analysis studies the possible behaviour of the plots. Analysis indicates that the reservoir anisotropy can be approximated during the infinite-acting flow at early times when other parameters are known. Further, when the first boundary is felt, in this case the vertical boundary, the horizontal permeability can be approximated during the transition flow periods at middle times. Finally, at late times when all the boundaries have been felt and a pseudosteady state flow is evident, reservoir dimensions can be approximated. These results can significantly improve well test analysis and enhance the performance evaluation of a horizontal well.

Channel Clearance by Perfectly Absorbing Boundaries in Synaptic Molecular Communications

Molecular reuptake is a nature-inspired channel clearance strategy to mitigate intersymbol interference (ISI) in molecular communications. Reuptake is especially important if the communication medium is not cleared of the information-carrying molecules by other means, and if it is not done properly, it decreases the maximum signal rate. In a more practical sense, in nature, reuptake failure may be detrimental to the organisms. Many neurological disorders, including schizophrenia, are related to problems with the reuptake mechanisms in synaptic molecular communications (SMC). To understand the evolutionary solution to the ISI, we start with the glutamate reuptake process as part of SMC. We develop a stochastic approach to the reuptake problem and derive analytic expressions for the probability of absorption for rectangular volumes. To test the validity of perfectly absorbing boundary approximation for real systems, we derive the rate of first incidence and average glutamate transport time for EAAT2, the most prevalent transport molecule. When applied to SMC, our results indicate that perfectly absorbing boundaries assumption is not possible according to the available physiological data, due to the limited number of transporters and the finite amount of time a transporter requires to reuptake a glutamate molecule.

Analysis of hybrid nanofluid and surface corrugation in the laminar convective flow through an encapsulated PCM filled vertical cylinder and POD-based modeling

In the present work, performance assessment of a PCM filled three dimensional vertical cylinder is conducted under the combined effects of surface corrugation and presence of binary nanoparticles in the heat transfer fluid. The numerical simulation is performed by using finite element method with varying values of Reynolds number (100≤Re≤750), number (1≤N≤8) and height (H/10≤h≤H/2) of rectangular type corrugation form and volume fraction of particles (0≤ϕ≤0.02) in unsteady configuration. Thermal transport features are enhanced while charging time is reduced for higher values of Reynolds number, solid volume fraction of the binary mixture in the heat transfer fluid. Complete charging time is reduced by 57% with increase of Reynolds number from 100 to 750 while it is reduced by 23% when nanofluid at the highest solid volume fraction is used instead of water. However, the corrugation parameters have reverse effects on the charging process. A computational framework for reconstruction of heat transfer fluid and PCM temperatures for the unsteady parametric configuration in the computational domain is offered by utilizing proper orthogonal decomposition (POD) technique with 25 modes for heat transfer fluid and 75 modes for PCM.

MATHEMATICS CREATIVE THINKING SKILLS INSTRUMENT TO SOLVE CUBE AND RECTANGULAR PRISM VOLUME PROBLEMS FOR ELEMENTARY SCHOOL STUDENTS

Mathematical creative thinking skills can help students solve mathematical problems with diverse, unique, and detailed solutions and strategies. This study aims to produce an instrument capable of obtaining information about students' mathematical creative thinking skills to solve the cube and rectangular prism volume problems for elementary school students. Research and development are applied in this research. The population of this research was sixth-grade elementary school students in Jakarta and West Java. The participants were 33 students in East Jakarta and 15 students in Purwakarta. The sample is based on purposive sampling. The instrument developed was an essay test question. The item validity test shows that the three items are considered accurate for measuring mathematical creative thinking skills correctly. The instrument is considered consistent for measuring mathematical creative thinking skills and can measure mathematical creative thinking skills on similar subjects at different times and places. The difficulty level of the three items is moderate, so that belonging is not too difficult or easy. The discrimination power of the questions is very good to discriminate the skills of students who are classified as high and low. Thus, the mathematical creative thinking skills instrument can be used to understand the mathematical creative thinking skills of sixth-grade and can also be used to measure the mathematical creative thinking skills of fifth-grade elementary school students on the same material for further research.

On the efficient enforcement of uniform traction and mortar periodic boundary conditions in computational homogenisation

In this contribution, the enforcement of uniform traction (UT) and periodic boundary (PB) conditions on arbitrarily generated meshes is analysed in detail, and the derivation of the associated macroscopic consistent tangent operators is described. Two different approaches to impose these boundary conditions are examined: the saddle point solution (SPS) resulting from the Lagrange multiplier method and the condensation method (CM). The numerical treatment required to implement the UT and the PB conditions with both methods is presented for rectangular and cuboidal representative volume elements (RVEs). It is shown that the UT condition only needs rigid body motion to be prescribed since it intrinsically restricts rigid body rotations in the finite strain setting. The application of the SPS to the UT condition leads to a formulation where the Lagrange multipliers are the homogenised stresses, and the macroscopic consistent tangent operator for FE2 simulations can be directly derived. The enforcement of PB conditions on non-conforming meshes with the mortar approach is also described for the CM and SPS. The need to modify the Lagrange multiplier dual interpolation functions is emphasised to avoid over-constraints. The proposed implementation recovers the conventional PB condition solution when conforming meshes are used. The computational performance of both methods is compared in terms of time and memory requirements. As anticipated, the results obtained for each boundary condition do not depend on the enforcement method employed. With the direct solvers employed, the SPS is more efficient despite increasing the number of unknowns in the linear system of equations.

Validation of a pseudo-3D phantom for radiobiological treatment plan verifications

Performing realistic and reliable in vitro biological dose verification with good resolution for a complex treatment plan remains a challenge in particle beam therapy. Here, a new 3D bio-phantom consisting of 96-well plates containing cells embedded into Matrigel matrix was investigated as an alternative tool for biological dose verification. Feasibility tests include cell growth in the Matrigel as well as film dosimetric experiments that rule out the appearance of field inhomogeneities due to the presence of the well plate irregular structure. The response of CHO-K1 cells in Matrigel to radiation was studied by obtaining survival curves following x-ray and monoenergetic 12C ion irradiation, which showed increased radioresistance of 3D cell cultures in Matrigel as compared to a monolayer. Finally, as a proof of concept, a 12C treatment plan was optimized using in-house treatment planning system TRiP98 for uniform cell survival in a rectangular volume and employed to irradiate the 3D phantom. Cell survival distribution in the Matrigel-based phantom was analyzed and compared to cell survival in a reference setup using cell monolayers. Results of both methods were in good agreement and followed the TRiP98 calculation. Therefore, we conclude that this 3D bio-phantom can be a suitable, accurate alternative tool for verifying the biological effect calculated by treatment planning systems, which could be applied to test novel treatment planning approaches involving multiple fields, multiple ion modalities, complex geometries, or unconventional optimization strategies.

Two-dimensional laboratory-scale DNS for knocking experiment using n-heptane at engine-like condition

A two-dimensional laboratory-scale DNS of a knocking experiment using a stoichiometric n-C7H16/O2/Ar mixture at engine-like condition with the latest reduced SIP isooctane kinetics was conducted. A compressible reactive flow solver PeleC combined with an in-house efficient chemical kinetics solver MACKS was used. The results of DNS were compared with a “knocking experiment by Kyushu University” conducted in a 14 × 14 × 80 mm rectangular constant volume chamber for the same mixture at an initial temperature of 480 K and pressure of 0.33 MPa. The comparisons showed the present DNS with the latest, validated reduced chemical kinetics successfully reproduced the knock onset timing within an error of 2% as well as the overall features of the experimental observations seen in the Schlieren images such as flame shape transitions, pressure history, and the characteristic faint increase in pressure due to the flame front attachment with the chamber wall. In addition, the present DNS captured that the cool flame ignition occurred homogeneously but accompanied by the rapid formation of density gradients vertical to the side walls in the unburned gas region.

Mass transfer through vapour–liquid interfaces: a molecular dynamics simulation study

ABSTRACT A quasi-stationary molecular dynamics simulation method for studying mass transfer through vapour–liquid interfaces of mixtures driven by gradients of the chemical potential based on the dual control volume (DCV) method is described and tested. The rectangular simulation volume contains three bulk domains: a liquid domain in the middle with vapour on each side such that there are two vapour–liquid interfaces. The mass flux is generated by prescribing the chemical potential in control volumes in the vapour domains close to the outer boundary of the simulation volume. The simulation method was applied for studies of two binary Lennard-Jones mixtures: one in which a strong enrichment of the low-boiling component at the vapour–liquid interface is observed and another in which there is practically no enrichment. The two mixtures differ only in the dispersive interactions; their bulk diffusion coefficients are similar. Furthermore, the prescribed chemical potential difference was the same in all simulations. Nevertheless, important differences in the mass flux of the low-boiling component were observed for the two mixtures at all studied temperatures which might be related to the enrichment at the interfaces.

Combination of FDTD With Analytical Methods for Simulating Elastic Scattering of 3-D Objects Outside a Fluid-Filled Borehole

We propose a hybrid method based on the finite-difference time-domain (FDTD) algorithm and analytical methods to solve the elastic scattering of 3-D objects outside a borehole. In the proposed method, the FDTD algorithm containing the incident waves generated by a borehole acoustic source is first used to calculate the wave fields inside a rectangular volume enclosing the object. Then, the reciprocity theorem for the wave fields in the fluid/solid configurations is employed to transform the near fields around the object into the far fields inside the borehole. This method uses the regional domain which tightly encloses the object, thus avoiding the simulation for the whole domain and leading to high efficiency for the large-scale and multiscale problems containing both the borehole and far-field objects. The validations with both analytical solutions and independent numerical methods demonstrate the accuracy and efficiency of the hybrid method.

Optimized Filling of a Given Cuboid with Spherical Powders for Additive Manufacturing

In additive manufacturing (also known as 3D printing), a layer-by-layer buildup process is used for manufacturing parts. Modern laser 3D printers can work with various materials including metal powders. In particular, mixing various-sized spherical powders of titanium alloys is considered most promising for the aerospace industry. To achieve desired mechanical properties of the final product, it is necessary to maintain a certain proportional ratio between different powder fractions. In this paper, a modeling approach for filling up a rectangular 3D volume by unequal spheres in a layer-by-layer manner is proposed. A relative number of spheres of a given radius (relative frequency) are known and have to be fulfilled in the final packing. A fast heuristic has been developed to solve this special packing problem. Numerical results are compared with experimental findings for titanium alloy spherical powders. The relative frequencies obtained by using the imposed algorithm are very close to those obtained by the experiment. This provides an opportunity for using a cheap numerical modeling instead of expensive experimental study.

O Protagonismo da Estrutura na Arquitetura do Edifício Vilanova Artigas - FAU-USP

O projeto do edifício da Faculdade de Arquitetura e Urbanismo da Universidade de São Paulo (FAU / USP) é de autoria do arquiteto Vilanovas Artigas, e recebe também seu nome. O projeto se destaca pela racionalidade construtiva, pela riqueza espacial e pelo aspecto didático com o qual os elementos construtivos são mostrados aos usuários do edifício, predominantemente estudantes de arquitetura. O projeto de 1961, foi executado entre 1966 a 1969. O concreto é usado em quase todo o edifício, fundações, vigas e pilares, e também no telhado e nas paredes. Destacam-se pilares externos que, posicionados fora da modulação estrutural, têm forma escultural, distinguindo-se dos demais pilares internos. Externamente, o edifício se apresenta como um volume retangular, suspenso no chão, sustentado pelos pilares esculturais, marcando as características do Brutalismo Paulista. Em contraste com a sobriedade e singularidade da forma externa, a espacialidade interna é muito dinâmica, resultado do jogo grandes balanços das lajes no vazio central, da alternância de aberturas e fechamentos e da generosidade dos espaços de circulação. Essa relação entre a arquitetura moderna e a concepção estrutural é explorada nesses estudos. O objetivo do presente trabalho é compreender os esforços a que a estrutura está sujeita por meio de ferramentas computacionais, como o software SAP 2000, verificar as justificativas construtivas, estéticas e didáticas da solução estrutural e destacar o protagonismo do sistema estrutural no resultado arquitetural.

Parametrical study of the dispersion of an alternative fire suppression agent through a real-size extinguisher system nozzle under realistic aircraft cargo cabin conditions

Nearly all active fire extinguishing systems consist of injecting an agent into the space set on fire. For aircraft cargo cabins, the agent widely used up to date is Halon 1301. The FAA provides a level of safety for this fire suppression agent that needs to be used in a volumetric concentration of 6% and needs to be acting for a duration of 0.5s. On the other hand, Halon 1301 is known to contribute to the retrenchment of Earth's atmospheric ozone layer, therefore it is going to be prohibited in the incoming years. The FAA has defined an equivalent level of safety in terms of the performance of the alternative agents. In this research, two different alternative fire suppression agents and two nozzles were tested at two vessel back-pressure conditions using a new design in purpose facility and an injection system able to control the injection pressure and the injection duration (the agent injected mass) in order to satisfy the FAA performance conditions. The discharge volume is a rectangular constant volume constant pressure vessel of approximately 0.85m3 and 1.5m of length that is provided with two transparent windows of 0.75m×1.5m to ensure an optical access to study the whole agent injection and it mixing process. Liquid phase distribution of the agent injected inside the vessel is measured by means of Diffuse Back-Light Illumination (DBI) technique. Vapor phase distribution, when present, is measured through the single-pass Schlieren technique. Results show a poor performance in terms of spatial distribution (narrow jet with little atomization) of the two alternative agents injected through the nozzle actually used in the aircraft cargo cabin fire suppression systems. However, simply replacing the nozzle and using one with a swirler showed excellent performance in terms of spray penetration and spreading angle. This results ratify that the nozzles of the fire extinguisher system currently used in the aircraft cargo cabin does not work for the alternative agents tested.

THE IDEA OF VERTICAL ZONING IN TOWN PLANNING CONCEPTS OF THE 1920–1930’s. AND ITS DEVELOPMENT IN MODERN ARCHITECTURE

In the 1920–1930’s in the Soviet Union much attention was paid to urban planning. From the very beginning, it was not only practical work related to solving the social, economic and technical problems of the city. In the process of creative searches, many different town-planning proposals were put forward, designed for a more or less distant perspective. One of the most interesting ideas in the town planning of that period was the idea of vertical zoning. Vertical zoning of the city is associated with the desire to eliminate the intersection of traffic flows and separate transport from pedestrians. In the most noteworthy projects, the houses were raised on pedestals, the intersection of pedestrian boulevards with transport highways took place at different levels. The first tier of urban development was allocated for public and communal institutions, higher residential floors were located. Such a development led to a completely different perception of the city by the townspeople. The houses lost the role of familiar screens, organizing the space of streets or squares. Now the buildings were overhead, and the spatial perspective acquired new opportunities. Such conditions changed the approach to composition of the city, opened new ways of its construction. As the solution to this issue appears the idea of a «top facade», which was to become the main concern of future architects and artists. On simple rectangular volumes standing on the ground of buildings, the upper tier of the city was to be complex in composition and form. It was designed for perception from various kinds of towers and overpasses, with air transport facilities. In this zone were to be located gardens, fountains, attractions, light posters, made in laced metal structures bridges between houses. In the absence of technical capabilities, these plans were not implemented. Despite the fact that the social ideas that fueled the town-planning projects of the 1920–1930’s. Gone, the idea ofvertical zoning proved to be fruitful and promising and developed in the architecture of the ХХ–ХХІ centuries.

New numerical model of heat and moisture transfer in the wet brick

The subject of this study is numerical modelling of the fully coupled heat and moisture transfer in the building material, i.e., in a brick. The new mathematical model of equilibrium transport of heat and moisture in the form of continuous liquid medium (funicular region), discontinuous liquid medium (pendular region) and gaseous phase with dry air is proposed. As independent variables, the total mass moisture content and temperature are chosen. Both energy and moisture balance equations are mutually coupled. It is due to dependence of capillary and vapor pressures on the moisture content and temperature. Additionally, vaporization and condensation phenomena are also accounted for in the energy balance equation. Both transport equations are supplemented with boundary conditions expressing the coupled heat and moisture transfer at the dried wall or heat transfer at impermeable walls. Balance equations are discretized on the rectangular control volume grid in the framework of the in-house computational code. A grid-based method of generation of the control volume mesh is proposed, with ‘half’ control volumes related to boundary grid nodes created at domain walls. This approach enables deeper insight into implemented code as well as simplifies analysis of influence of selected terms in balance equations and implementation of complex hygro-thermal boundary conditions.