Article Per Year (5 Year)
p-Index From 2021 - 2026
0.444
P-Index
This Author published in this journals
All Journal International Journal of Renewable Energy Development International Islamic Medical Journal
Ali Jafari, Ali
Department of Mechanical Engineering of Biosystems, University of Tehran, Alborz
Religion Humanities Chemistry Energy Health Professions Medicine & Pharmacology Public Health

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Analytical and Numerical Solution for H-type Darrieus Wind Turbine Performance at the Tip Speed Ratio of Below One Ghiasi, Pedram; Najafi, Gholamhassan; Ghobadian, Barat; Jafari, Ali
International Journal of Renewable Energy Development Vol 10, No 2 (2021): May 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.33169

Abstract

H-type Darrieus vertical axis wind turbines (VAWT) have omnidirectional movement capability and can get more power compared to other VAWTs at high tip speed ratios (𝜆). However, its disadvantages are self-starting inability and low generated power at 𝜆 less than 1. The performance of H-type Darrieus wind turbine at 𝜆<1 was studied using double multiple stream tube (DMST) model and two-dimensional computational fluid dynamic (CFD) simulation. In CFD simulation, the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations were used and the turbulence model was solved with SST k-ω model. The performance of fifteen various wind turbines was determined at fourteen wind velocities by two solution methods. The effect of chord length, solidity, Reynolds number and Height to Diameter (H/D) ratio were investigated on generated torque, power and the time required to reach 𝜆=0.1. Increasing in the moment of inertia due to the increasing in required time to reach 𝜆=0.1. In the low TSRs, the wind turbines can generate higher torque and power in high Re numbers and solidities. The required time was reduced by an increase in Re number and solidity. Finally, the best ratio of H/D of H-type Darrieus wind turbines was defined to improve the turbine performance.
Wind Turbine Rotor Simulation via CFD Based Actuator Disc Technique Compared to Detailed Measurement Mahmoodi, Esmail; Jafari, Ali; Keyhani, Alireza
International Journal of Renewable Energy Development Vol 4, No 3 (2015): October 2015
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.4.3.205-210

Abstract

In this paper, a generalized Actuator Disc (AD) is used to model the wind turbine rotor of the MEXICO experiment, a collaborative European wind turbine project. The AD model as a combination of CFD technique and User Defined Functions codes (UDF), so-called UDF/AD model is used to simulate loads and performance of the rotor in three different wind speed tests. Distributed force on the blade, thrust and power production of the rotor as important designing parameters of wind turbine rotors are focused to model. A developed Blade Element Momentum (BEM) theory as a code based numerical technique as well as a full rotor simulation both from the literature are included into the results to compare and discuss. The output of all techniques is compared to detailed measurements for validation, which led us to final conclusions.
Different Approaches to Islamic Medicine in Iran Jafari, Ali; Parizi, Mohammad Sohrabian
Jurnal Medis Islam Internasional Vol 5 No 1 (2023): December
Publisher : UNUSA Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33086/iimj.v5i1.4953

Abstract

Background: Subject and objectives: Using the capabilities of Islamic civilization is one of the topics that has attracted the attention of contemporary Islamic thinkers. In this context, various opinions have been presented about whether medicine is Islamic or not among Iranian thinkers. In this article, we seek to examine the negative and positive opinions about the nature of Islamic medicine. The purpose of this article is to find a precise definition of Islamic medicine and provide a correct solution in using this treatment model. Result: This research deals with the study of Islamic medicine through descriptive-analytical and documentary methods. In this research, a complete search of electronic banks, related books, and internet sites was conducted and all acceptable articles were reviewed completely and systematically. There are different views on the nature of Islamic medicine, each of which has looked at the issue from its own angle, some agree with it and some oppose it. Conclusion: Islamic medicine has very good capacities, although there are serious criticisms against it. Islamic medicine is a specialized science, and a common opinion should be reached about its limits and conditions, and a system should be designed and drawn for it. The revival of Islamic medicine will contribute to the development of the modern Islamic civilization.
Co-Authors Alireza Keyhani, Alireza Esmail Mahmoodi, Esmail Ghiasi, Pedram Ghobadian, Barat Najafi, Gholamhassan Parizi, Mohammad Sohrabian