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Showing 2 results for Torques
Determining the Effect of Productivity Shock and Fluctuation Shock of Foreign Exchange Earning on the Household Asset Basket in the Iranian Economy using Dynamic Stochastic General Equilibrium Approach
Mr. Habib Mosavi, Dr Nader Mehregan, Dr Mohammedreza Yousefi Sheikh Robat,
Volume 21, Issue 3 (9-2021)
Abstract 
Financial markets, especially the capital market, may have strong links with other economic sectors. One of the most important aspects of investment is to determine the “optimal investment portfolio”. To date, some research has been conducted to determine the optimal portfolio with” artificial intelligence” and “Fuzzy Logic”. However, we determine the optimal portfolio based on Dynamic Stochastic General Equilibrium (DSGE) model. This study examines the design and calibration of the new Keynesian dynamic stochastic equilibrium model related to an optimal investment portfolio and the effect of shocks such as productivity shocks and foreign exchange earnings’ fluctuation shocks on macroeconomic variables. To this end, we design a DSGE model with sectors of households and firms, government and the central bank, and calibrate the model’s parameters after logarithm–Linearization using seasonal data of 1996-2016 and results of empirical studies. In the designed model, households maintain a portfolio of stocks, cash, securities, and other assets based on risk and return or an optimal portfolio. In the end, we assess the impulse response function of economic variables to shocks of productivity and foreign exchange earnings. Ultimately, the comparison of the present moments in the current study and moments of real data indicates the relative success of the model with regard to the realities of Iranian economy.
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Numerical simulation and experimental evaluation of an unsteady flow around forced rotating cylindrical prototype with three orthogonal plates

Volume 22, Issue 11 (11-2022)
Abstract
In general, rotating objects always produce different rotational torques according to different dimensions and rotational speeds. In some cases, it can cause a lot of damage to equipment, so it is necessary to be aware of the amount of torque that rotating objects produce at different rotational speeds, as well as in the presence or absence of air flow. in this study, numerical and experimental analysis of non-continuous flow around a cylindrical model with vertical plates under forced rotation is performed and its main purpose is to measure the torque of rotating objects in the presence of wind current also to stabilize rotation. Rotational speeds are constant. First, an aerodynamic torque measuring device was built and then a 3-fin cylindrical model was tested in a wind tunnel, and numerical simulations of 3 and 2 fin models were performed in the same laboratory conditions by Ensys Fluent software. A good agreement was observed between the experimental and numerical results and the maximum error between them was less than 10%, which is acceptable. From the simulation results, it was observed that in every 180 degrees of rotation that the maximum cross section of the models is exposed to direct wind flow, the maximum torque produced by the 2-blade cylindrical model is 30% higher than the maximum torque produced by the 3-blade model. As the wind speed increases from 20 to 60 meters per second, the torque of the 3-fin model increases from 0.4 to 1.2 Nm, which is equivalent to 200%.
 
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