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Imbalance between resources and expenditures, inefficient investment management of available, the need for structural reform and the successful experience of a multi-pillar social security system in some countries, have encouraged this system in Iran. Research aims to identify and prioritize the challenges and impeller forces effective in the implementation of this system and evaluate the resources organization and develop and select scenario. The research modeling was carried out using DEMATEL technique and data analysis done with ANP. The research method is descriptive, and based on a survey of experts that includes 45 social security managers in Isfahan province. The results showed that the most effective challenge group is the "Challenges of Insurance and Retirement" and the "Proximity to The Financial Breakeven Point" is a major sub-challenge. Also, two factors of "sustainable financing" and "interaction of related institutions and organizations" were identified as two forces behind the establishment of this system. By placing these two propellers on the Schwartz matrix, the most probable scenario detected as the Honey free hive.

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In this research, the aerodynamic design of a centrifugal compressor is carried out using an inverse design method. At the first step of the aerodynamic design, the shape modification capability of compressor meridional plane is generated by linking up the Ball-Spine inverse design algorithm as a shape modification algorithm and quasi 3D analysis code as a flow solver. Then, the meridional plane is modified by improving the hub and shroud pressure distribution and applying it to the inverse design code. At the second part of this research, by developing a novel design method on the blade to blade plane, and incorporating it into the quasi 3D flow solver, the 3D profiles of impellers will be obtained in order to reach the higher blade loading. Finally, to check the outcome of design process, the current and the modified impellers are analyzed using the full 3D flow solver, CFX. The results are the representatives of about 5 percent enhancement in compressor total pressure ratio.

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In this article, a special duct is introduced in which, inlet water jet initiates to oscillate after a short time and it causes the velocity and pressure to oscillate regularly. Considering that there is a linear relationship between the inlet jet velocity and its oscillations frequency, the flow rate can be calculated by measuring the pressure frequency. In order to study the flow field inside the current geometry of fluidic oscillator and also to find the optimum location for sensor to detect the pressure oscillation, the unsteady turbulent Navier-Stokes equations are solved by ANSYS CFX software. Having studied the grid independency, capability of K-ε and SST turbulence models for numerical simulation of unsteady flow inside the fluidic oscillator is considered. Then, according to the peak to average ratio (PAR) criterion, the qualities of pressure signals are compared at some points, to distinguish an optimum pressure sensor position. Afterwards, a prototype of fluidic oscillator flow meter is manufactured for the first time in Iran. Using this prototype and inserting the pressure and Piezoelectric sensor at the optimum point, the numerical simulation results are validated by the experimental data. Comparison between the numerical and experimental results shows that the SST model is more suitable for this flow simulation. Finally, by performing experiments in different flows, acquiring and processing pressure signals, the flow meter characteristic diagram (inlet jet oscillations frequency- inlet jet velocity) are extracted.

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Purpose: This study was conducted in order to identify and structure the financial crisis of the social security organization using the SSM method. The results of this research can be used to determine changes in this organization.

Methodology: To identify and structure the problem, CATWOE and soft systems methodology have been combined. Therefore, the current research is applied research with inductive-deductive logic, which is an example of a qualitative mixed method. The data of the research are the opinions of experts, whose number is 28, and they were selected in a purposeful way. Research has been done in two main stages, which are extracting the structure of the problem and identifying solutions.

Findings: In this research, the structure of the financial crisis of the social security organization (rich image) and the factors related to it were determined. In addition, it was found that in order to solve the crisis, reforms should be made in governance and organization measures in three areas: policy, economy and supervision.

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In this study, the radial flow turbine of a cooling turbine is investigated numerically and then compared with the experimental results at some operation conditions. Performance characteristics of the compressor are obtained experimentally by measurements of rotor speed and flow parameters. In this investigation, the turbine performance curve is obtained and three dimensional flow field in the turbine is analyzed. The rotor and casting geometry are modeled in BLADE GEN and CATIA softwares respectively. The TURBO GRID software is used for grid generation of rotor while the ANSYS MESH software is applied for grid generation of casting. Finally, 3D numerical solution of fluid flow in the turbine is solved by CFX flow solver. In this approach, compressible flow equations are solved according to the pressure based method with SST turbulence model. To ensure the numerical results, the grid independency is studied. Finally, the performance characteristics of the turbine are obtained numerically which are then compared to the experimental results. The comparison shows good agreement between numerical and experimental results.

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Inverse design is one of the design methods of aerodynamic ducts such as S-duct intakes. In these problems, the geometry of the duct is unknown but the pressure distributions along the walls are given. In this paper, a new inverse design method called “flexible string method” is introduced. In this method, the duct walls are modified from initial guess to final shape based on the flexible string movement algorithm according to pressure distribution. In 3D design, the duct design process starts with a 2D one. At first step, a 2D Jet-Engine S-shaped air intake considering flight mach number is designed using the inverse design method based on an Euler flow solver (with no considering the jet nose engine effects). At the second step with considering duct sections like circle, ellipse and bean the 2D duct is modified to obtain the 3D duct. Finally, it is validated by analyzing the duct flow in 3D turbulent regime. The numerical studies show in spite of severe height change with respect to duct length, there is no separation in the duct and the uniformity of flow at the duct exit is completely satisfactory.

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The ratio of lift to drag coefficient in wind turbine blades is within the most important parameters affecting the power coefficient of wind turbines. Due to the performance of Magnus wind turbines in low speed air flow; such turbines are attractive for research centers. In the present work, a new geometry for the blades of Magnus wind turbines is defined. The defined geometry is based on the geometry of a Treadmill with a difference that the diameter of its leading circle is greater than that of its trailing one. In the present work, the body is supposed to a low speed air flow while a tangential velocity is applied to the airfoil surfaces and then, its effect on the lift and drag coefficient is studied by numerical method. The effect of generated tangential velocity on the surfaces is investigated for different air flow speed and attack angles and then, its results are compared with that for stationary surfaces. The results show that generating tangential velocity along the surfaces caucuses the lift and drag coefficients and, their ratio to be varied, greatly. By the tangential movement of the surfaces, the maximum ratio of lift to drag coefficient occurs in zero attack angle which is equal to 109. Moreover, maximum magnitude of lift to drag coefficient for attack angles 5, 10, and 15 degrees are 81, 64, and 57; respectively.

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In this research an inverse design algorithm, called ball-spine algorithm (BSA) is developed on a 90-degree bend duct between the radial and axial diffuser of a centrifugal compressor with viscous swirling inflow to bend duct. The shape modification process integrates inverse design algorithm and a quasi-3D analysis code. For this purpose, Ansys CFX software, is used as flow solver and inverse design algorithm is written as a code inside it. Shape modification is accomplished for viscous and inviscid flow to check the effect of viscosity on convergence rate. Also, the effect of swirl velocity in shape modification process is investigated, by considering increased pressure as the target parameter. The algorithm reliability for swirling flow is verified by choosing different initial geometries. Finally, aerodynamic design of the bend duct with BSA is accomplished to reduce losses in 90-degree bend. Shape modification process is carried out by improving the current wall pressure distribution and applying it to the inverse design algorithm. Results show that convergence rate and stability of BSA are favorable for designing ducts with swirling viscous flow. So that, the pressure recovery coefficient of the 90-degree bend duct is 4%increased.

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The purpose of this paper is to investigate theLow-Density Lipoproteins (LDL) mass transfer in vessel walls using the Lattice Boltzmann Method (LBM). High Schmidt number of LDL leads to numerical instability of LBM.In order to solve this problem, LBM and finite volume method (FVM) are combined.In this hybrid method, the blood velocity field is solved by LBM using the single relaxation time, SRT, model and FVM has been used for LDL concentration equation. LBM is able to simulate flow and mass transfer for the Schmidt number, Sc, up to 3000 only if the time consuming multi relaxation time is used. However, the purposed hybrid method suggested in this article can be used to solve the problem for Sc as high as 107. Good agreement between our results obtained from the hybrid simulation and the available results in the literature and noticeable decrease in CPU time compared with when the LBM is used for both flow and mass transfer, indicates the ability of the hybrid method.Finally, the hybrid methodis used to simulate the mass transfer of LDL particles and investigate the effective factors for increasing the surface concentration, such as the size of LDL particles, wall suction velocity, wall shear stress, Newtonian and non-Newtonian fluids behavior and change of concentration boundary layer with various Schmidt number.