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Open Access Article
1 - Mathematical modeling of fluid flow and heat transfer over a stretching surface in a porous medium
Mahmoud ZarriniIn the current research, fluid flow and heat transfer over a stretching surface in a porous medium were studied; And a mathematical model for the boundary layer equations of its stretching surface based on the Navier-Stokes equations was presented in the form of partial MoreIn the current research, fluid flow and heat transfer over a stretching surface in a porous medium were studied; And a mathematical model for the boundary layer equations of its stretching surface based on the Navier-Stokes equations was presented in the form of partial differential equations and boundary conditions; that these equations were changed in the form of ordinary differential equations with boundary conditions by changing certain variables; And with the shooting numerical method, the boundary conditions of the model were changed to the initial conditions. Finally, an analytical solution for the fluid flow velocity was obtained and to find the heat transfer, the energy equation was solved by using the numerical method of Ronge-Kutta.Repeat (In the current research, fluid flow and heat transfer over a stretching surface in a porous medium were studied; And a mathematical model for the boundary layer equations of its stretching surface based on the Navier-Stokes equations was presented in the form of partial differential equations and boundary conditions; that these equations were changed in the form of ordinary differential equations with boundary conditions by changing certain variables; And with the shooting numerical method, the boundary conditions of the model were changed to the initial conditions. Finally, an analytical solution for the fluid flow velocity was obtained and to find the heat transfer, the energy equation was solved by using the numerical method of Ronge-Kutta.) Manuscript profile -
Open Access Article
2 - An Analytical Solution of the non-Darcy Flow Governing Equation the Homotopy Analysis Method Using
Amirhossein Arvin Mohammad Hadi Fatahi Mohammad Sedghi-Asl Seyed Abbas MohammadiBackground and Aim: The Homotopy Analysis Method (HAM) was first proposed by Liao (1992) to solve functional equations. This method is based on homotopy and provides an approximate-analytical solution for functional equations. In recent years, this method and its modifi MoreBackground and Aim: The Homotopy Analysis Method (HAM) was first proposed by Liao (1992) to solve functional equations. This method is based on homotopy and provides an approximate-analytical solution for functional equations. In recent years, this method and its modifications have been effectively used to solve a wide range of linear and nonlinear problems in applied sciences to find solutions to series of various types of nonlinear equations, including algebraic equations, ordinary differential equations, partial differential equations, and differential-integral equations (Abbasbandy et al. 2006). The purpose of this research is to provide an analytical solution of time delay with acceptable accuracy for the non-linear equation of non-Darcy flow in coarse-grained media using the HAM method, which previous researchers had recommended to conduct further research in this field. Method:In this research, the governing equation of the non-Darcy flow was solved by the HAM method for the first time, then the water level profiles of the final equation of the HAM method obtained for the 6 inlet flow rates with different boundary conditions and in two coarse-grained porous media including rounded and sharp-edged materials. The results of the water level profile using the HAM method have been compared with the laboratory data of Sedghi Asal (2010) reported at the Stuttgart laboratory in Germany. The normal objective function (NOF) has been used to compare the HAM method results with the experimental data of Sedghi Asal (2010). Results: The comparison of the results of HAM method with the experimental data of Sedghi Asal (2010) has been done under upstream and downstream boundary conditions for different discharges and with a slope close to the horizon S = 0.00001. The results have shown that flow rates of q=30 lit/s, with a NOF error percentage of 0.000099828 in the porous medium of sharp corners and q = 26.25 lit/s, with a NOF error percentage of 0.000102162 in the porous medium of round corners depict better accuracy than the experimental data in higher input flow rates. This method has logical solutions in horizon slopes and the water level profiles in HAM method and experimental data have coincided or are close to each other in most of the points. However, the subject of permanent and uniform flow needs a dependent research. Conclusion: The results showed that the water level profiles are close to each other in most cases. This illustrates the accuracy of the developed approach based on HAM method. However, when the difference between the upstream and downstream water levels increases, the percentage of error escalates. In other words, with the increase of the hydraulic gradient in the porous medium, the error also grows. Finally, by evaluating the results of the HAM method compared to the laboratory data, it can be concluded that this method shows better accuracy in the porous medium with sharp-cornered materials compared to round-cornered materials due to higher flow rates and higher porosity of this media. Manuscript profile -
Open Access Article
3 - Investigating the Effect of Noise on Temporal Prediction of Grouneater Flow and Contaminant Transport in Porous Media using Artificial Intelligence Models
Shahram Mousavi Vahid Nourani Mohammad Taghi AlamiBackground and Objective: Uncertainties of the field parameters such as hydraulic conductivity and dispersion coefficient, unknown boundary conditions and the noise of the measured data are among the main limiting factors in the groundwater flow and contaminant transpor MoreBackground and Objective: Uncertainties of the field parameters such as hydraulic conductivity and dispersion coefficient, unknown boundary conditions and the noise of the measured data are among the main limiting factors in the groundwater flow and contaminant transport (GFCT) modeling. Method: Miandoab plain was investigated as a case study for simulating groundwater level (GL) and chloride concentration (CC). This paper presents an artificial intelligence-meshless model for temporal GFCT modeling. In this study, time series of groundwater level (GL) and chloride concentration (CC) observed at different piezometers of Miyandoab plain (in Iran) were firstly de-noised by the wavelet-based data de-noising approach. Then, the effect of noisy and de-noised data on the performance of artificial intelligence model was compared. For this end, time series of GL and CC observed in 14 different piezometers were trained and verified via artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) models to predict the GL and CC at one month ahead. Findings: The results showed that the threshold-based wavelet de-noising approach can enhance the performance of the modeling up to 25%. Reliability of ANFIS model is more than ANN model in both calibration and verification stages duo to the efficiency of fuzzy concept to overcome the uncertainties of the phenomenon. Discussion and Conclusion: Waveletde-noising approach as a data preprocessing method enhances the performance of the artificial intelligence model in temporal modeling of GFCT. Manuscript profile -
Open Access Article
4 - Review of Moisture Movement Mechanisms in Plant Tissues Using Transfer Models in Porous Media – Part I: Moisture Transfer Models
Fatemeh Mozafari ghorba Mohammadmehdi Maharlooei Ahmad Gazanfari MoghaddamWater transfer in plant tissues is a complex phenomenon. The cell wall and plasma membrane are permeable to water and the amount of water exchange among cells and the intercellular space mainly depends on the amount of intracellular water pressure and the viability of t MoreWater transfer in plant tissues is a complex phenomenon. The cell wall and plasma membrane are permeable to water and the amount of water exchange among cells and the intercellular space mainly depends on the amount of intracellular water pressure and the viability of the cell membrane. The movement of water within the plant tissues includes simultaneous heat and mass transfer and therefore the thermophysical properties of the plant tissue plays an important role in this transition. Capillary pressure, intrinsic permeability, relative permeability, effective moisture diffusivity, and thermal conductivity are the key thermal and transport properties needed for comprehensive investigation of moisture transfer mechanism in plant tissue. The plant material can be considered as a porous medium in a non-steady state, which contains about 10 - 80% water. Molecular diffusion for gases (water vapor and air), capillary influence for the liquid (water) and advection mechanisms (Darcy flow) are used in the drying model in porous media. Thus, multiphase models can be used to study the water movement in plant tissues. In multiphase models of transmission mechanism, transfer of water into two types of liquid and gas is investigated simultaneously under the influence of temperature and other properties of plant tissue. In this article, the plant tissue is considered as a porous medium and the factors affecting the moisture transfer in these tissues are discussed. Manuscript profile -
Open Access Article
5 - The principles of heat transfer and fluid mechanics in porous media (review)
mehrdad mesgarpour Ali Heydari seyfollah saddodinPorous materials are encountered literally everywhere in everyday life, in technology, and in nature. With the exception of metals, some dense rocks, and some plastics, virtually all solid and semisolid materials are "porous" to varying degrees. There are many examples MorePorous materials are encountered literally everywhere in everyday life, in technology, and in nature. With the exception of metals, some dense rocks, and some plastics, virtually all solid and semisolid materials are "porous" to varying degrees. There are many examples of porous materials in everyday life and the environment. Textiles and leathers are highly porous; they owe their thermal insulating properties, as well as the property that they "breath ," to their pore structure. Paper towels and tissue paper are also highly porous; these owe their absorbency partly to their porous structure and partly to the property that they are strongly wetted by water. In this study, mathematical model and formula based on porous media will be discuses. Manuscript profile -
Open Access Article
6 - طراحی داربست هیبریدی متخلخل برپایه چندسازه PEPC اصلاحشده با کیتوسان به منظور کاربرد در مهندسی بافت نرم: بررسی شباهت های ساختاری و رفتار زیست مکانیکی
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