A method for adaptive refinement of a triangular mesh for solution of the steady and unsteady Euler equations is presented. An upwind, finite volume based on Roe"s flux difference splitting method is used to discretize the equations. By using advancing front method an initial regular Delaunay triangulation has been made. The adaptation procedures involve mesh enrichment and mesh coarsening to either add points in high gradient regions of the flow or remove points where they are not needed, respectively, to produce solutions of high spatial accuracy at minimal cost. Steady transonic results are shown to be of high spatial accuracy, primarily in that the shock waves are very sharply captured. Unsteady results obtained for a moving shock wave in a two-dimensional domain show the precise enrichment and coarsening procedure. The results were obtained with large computational savings when compared to results for globally-enriched mesh with cells subdivided as many times as the finest cells of the adapted grid.

Journal bearings are widely used in different machineries. Reynolds equation is the governing equation to predict pressure distribution and load bearing capacity in journal bearings. There are many analytical and numerical methods for solving this equation. The main disadvantage of these methods is their inability to analyze complex geometries. In this paper, a comprehensive method based on Dynamic mesh method is developed to solve the conservation equations of mass, momentum and energy. This method has smaller error compared to other techniques. To verify the accuracy of this method, the bearings with different length to diameter ratios are analytically and numerically analyzed under different loads and compared with each other.In continue, the turbocharger’s bearing is numerically simulated and the effects of rotational speed change are studied. Finally, the turbocharger’s bearing with four axial grooves are simulated. The simulations results show that adding grooves to the turbocharger’s bearing causes the bearing eccentricity ratio and lubricant flow rate to increase and the attitude angle, rate of temperature rise and frictional torque to decrease.

Internal ballistics of solid rocket motor is simulated by solving the axisymmetric Navier-Stokes equations on a moving unstructured grid. Then, the flow velocity, pressure, temperature, and other variables are computed for problems with complex geometries and boundary conditions. The Dynamic (moving) mesh is used to model flows where the shape of the domain changes with time due to motion of the domain boundaries (burning surfaces).Updating of the mesh is handled automatically at each time step, based on the new position of the boundaries. This study showed that CFD with unstructured Dynamic meshing can be a powerful tool for simulating internal ballistics of solid rocket motors.

his study analyzes the free vibration, forced vibration, resonance, and stress wave propagation of orthotropic sandwich plates made of functionally graded materials (FGMs). Dynamic analyses are conducted using a mesh-free method based on first-order shear deformation theory and the shape functions constructed using moving least squares approximation. The sandwich plates are rested on a Pasternak elastic foundation and subjected to periodic or impact loading and essential boundary conditions, which are imposed through a transfer function method. The sandwich plates are assumed to be composed of a homogeneous orthotropic core and two orthotropic FGM face sheets made of two orthotropic materials. The volume fractions of the materials are varied smoothly along the thickness of the face sheets. The convergence and accuracy of the applied method are demonstrated, after which numerical analyses are conducted to investigate the effects of elastic foundation coefficients, material distributions, geometrical dimensions, time-dependent loading, and boundary conditions on the vibrational and Dynamic characteristics of the orthotropic FGM sandwich plates.

In this article, turbulent flow in a cycle of internal combustion engine has been analyzed by OpenFOAM software. The cycle consists of suction, compression, expansion and exhaust. A two dimensional geometry has been used and moving boundaries in valves and piston have been simulated by using Dynamic mesh.Three types of changing topology have been used which consist of add or removal layers of cells for simulation of moving piston, sliding mesh for simulation of valves and attach or detach boundaries for simulation of intake and exhaust ports. The k- estandard model has been used for turbulent flow and the problem has been solved for two rotational speeds 1500 and 3000 rpm, respectively. The contours of pressure and vector plots of velocity are presented. Asymmetry of flow in exhaust port at the end of the cycle is evident. Also swirl increases due to increasing of rotational speed. Using Dynamic mesh has caused achieving of flow’s details. So, numerical simulation could replace difficult experimental methods.

The application of the Immersed Boundary Method (IBM) coupled with Adaptive mesh Refi nement (AMR) is considered to be one of the powerful tools for solving complex viscous incompressible ow problems. In this paper, the Kajishima-cut-cell IBM is combined with AMR to solve the ow of complex incompressible, viscous fluid, and rigid body problems. In the IBM, the solid and fluid motions at the interface are controlled by a body force that can be calculated with a fraction of solid volume. The objective is to develop an automatic adaptive mesh refinement strategy to enhance the solution in proximity to the fluid-structure interface. This is necessary as the flow field might be significantly affected by the structure boundaries; therefore, it is essential to capture the boundary layers precisely. The capability of this method can be demonstrated through computational results to improve the ow resolution near the fluid structure. The proposed approach is validated using a 2D laminar ow numerical example. The approach is validated in terms of accuracy and performance. The combined IBM-Adaptive mesh refinement approach showed a promising outcome for the investigated problem. The result of the implemented method achieved an acceptable error performance within a reasonably low computation time.

Background & Aim: Aerobic activities and herbal supplements are used as a methods to control and reduce many diseases caused by oxidative stress, including lung diseases. The aim of this study was to investigate the effect of 8 weeks of aerobic training and coriander seed supplementation on some indicators of oxidative stress and ATP levels in lung tissue of male rats poisoned with hydrogen peroxide. Methods: 42 adult male Wistar rats were randomly divided into 7 groups: control, poisoning, poisoning+ 5 mg/kg coriander extract (supplement 1), poisoning+ 10 mg/kg coriander extract (supplement 2), poisoning + exercise, poisoning+ Exercise+ Supplement 1, Poisoning+ Exercise+ Supplement 2. Interventions included 8 weeks (5 training sessions per week) running on a treadmill for 60 minutes and injecting coriander seed extract at doses of 5 and 10 mg/kg over two weeks. Tissue concentrations of ATP, MDA and PAB indices were evaluated using special kits and the data were analyzed by two-way analysis of variance at a significance level of 0. 05. Results: Eight weeks of aerobic training significantly increased the concentration of ATP and significantly decreased the concentration of pulmonary PAB (P<0. 05),While it had no significant effect on MDA index (P> 0. 05). On the other hand, only 10 mg/kg of coriander extract caused a significant increase in ATP concentration and a significant decrease in PAB in lung tissue (P<0. 05). The interaction of aerobic exercise with doses of coriander seed extract also caused a significant increase in ATP concentration and a significant decrease in MDA and PAB concentration (P<0. 05). Conclusion: Despite the effect of interventions in modulating the effect of poisoning of some indicators, the greatest effect was observed during the interaction of aerobic exercise and high doses of coriander extract.

The Multiquadric Radial Basis Function (MQ-RBF) method, despite its advantages, has not yet been developed to be used for Dam-Reservoir-Foundation Interaction (DRFI) problems. In this study, this mesh-less method was developed for solving the DRFI systems in the frequency domain. A new domain decomposition technique was also used for analyzing Dynamic interaction problems for the first time in MQ-RBF. In this regard, the computational domain is divided into dam, reservoir, and foundation subdomains. Then, the MQ-RBF method is separately applied to each subdomain. For applying the Dynamic interaction between two adjacent subdomains, two Multiquadric shape functions must be considered for each computational center on their interaction boundary. Besides, each shape function is also defined using the computational centers in the subdomain. One of the important challenging issues in RBFs is the determination of the Optimal Shape Parameter (OSP). Thereafter, some new relations in terms of the earthquake frequencies are proposed for the OSPs in different cases of the interaction systems. In this regard, a few frequency magnitudes were considered and, consequently, different relations were presented for all frequencies using the obtained OSPs. It is found that, the OSP does not depend on the shear modulus of neither the dam nor the foundation. Moreover, the OSP value are not sensitive to the fluid compressibility and do not depend on the number of subdomains. Apparently, these properties reduce the computational costs and facilitate the MQ-RBF application. In order to validate the capabilities of the approach, nine numerical examples are solved in which the Roots Mean Square Error (RMSE) criterion has been evaluated for comparing the results with those of the exact and FD methods. Results show that the proposed method is of acceptable accuracy, i.e. more accurate than FD even with much more FD computational nodes. Also, it is shown that the errors increase by increasing the earthquake frequency value while the FD errors seem to be unacceptable in frequency values close to the resonance frequency, unlike those of the MQ-RBF.

Introduction: Changes in gene expression and protein expression of the spinal-blood barrier play an important role in the transmission and development of neuro-inflammatory responses. In order to increase the knowledge related to the role of environmental interventions affecting the tight junction and adhesive proteins of this barrier, this study investigated the effect of four weeks of resistance training and date pollen/testosterone extract on gene expression and protein expression of occludin and cadherin in male rats. Methods: In an experimental design, 30 male Wistar rats randomly divided into 6 groups: Control,Resistance training,DPP extract,Testosterone,DPP extract+ resistance training,Testosterone+ resistance training. The amount of 100 mg/kg date pollen extract was fed to mice by gavage for 4 weeks. Also, synthetic testosterone with a dose of 2 mg/kg was used subcutaneously as a positive control. Resistance training consisted of a four-week increasing training period on a 50-step ladder with 8 to 12 repetitions per session. After the intervention, gene expression was measured by RT-PCR method and protein expression was measured by western blot method. Results: Four weeks of resistance training caused a significant increase in occludin gene expression (P=0. 010) and cadherin (P=0. 015),While it had no significant effect on the protein expression of occludin (P=0. 404) and cadherin (P=0. 647). Also, the gene expression level of two proteins increased significantly under the influence of date pollen extract and testosterone (P<0. 05). On the other hand, the protein synthesis rate of occludin (P=0. 016) and cadherin (P=0. 012) was increased only in the group receiving synthetic testosterone. Despite the fact that the highest level of gene expression of two proteins was observed when the interventions were combined simultaneously, there was no statistically significant difference between their synergistic effects (P=0. 059). However, the highest expression of occludin and cadherin protein occurred when resistance training was combined with testosterone supplementation (P<0. 05). Conclusions: The results of this study showed that DPP extract is superior to other interventions for increasing the gene expression of occludin and cadherin proteins of the blood-spinal barrier and testosterone for increasing the expression of these proteins. The combination of these interventions with the double promotion of the signaling process of gene and protein expression will maintain the integrity and reduce the permeability of the blood-spinal cord barrier in healthy male animal samples.

Due to the lack of measurements in many regions, wave characteristics are estimated using different methods. Wave climate hindcasting/forecasting is mostly conducted by numerical models or empirical methods. Until now, different empirical methods have been developed for wave hindcasting. However, with the development of high speed processors, several sophisticated numerical models have been developed for wave prediction. These models are mostly phase-averaged spectral wave models developed in three generations. In the last two decades, third generation wave models have been used widely in academic and practical projects. In this regard, Port and Maritime Organization has produced his own model, PMO Dynamic. This model has been developed as a part of first three phases of Monitoring and Modeling of Study of Iranian Coasts project. PMO Dynamic package is a software available for engineering purposes. It has several modules that have been developed for different objectives. Wave model is the module which is used for the generation and transformation of wind waves in coastal areas. In this paper, in order to test the PMO Dynamic model capabilities, it has been applied for the prediction of wave parameters in Bushehr Bay and the results have been compared with MIKE21 SW model and measured data.