Karaj Islamic Azad University is probably the most populated branch of Islamic Azad University which was established in Karaj in 1984 . It started its activities with 500 students who studied in 7 fields of study. Nowadays this big university complex consists of 11 faculties, 1 high college, 1 technical college and 1 educational center and 3 research centers. In the beginning of 2011, about 30,000 students studied in this branch of Islamic Azad University. Wikipedia.
Ezzati R.,Islamic Azad University at Karaj
Soft Computing | Year: 2011
In this paper, the main aim is to develop a method for solving an arbitrary general fuzzy linear system by using the embedding approach. Considering the existing and uniqueness of fuzzy solution to n × n linear fuzzy system is done. Numerical examples are presented to illustrate the proposed model. © 2010 Springer-Verlag.
Shalchi-Tabrizi A.,Sharif University of Technology |
Seyf H.R.,Islamic Azad University at Karaj
International Journal of Heat and Mass Transfer | Year: 2012
Effect of using Al 2O 3-water nanofluids with different volume fractions and particle diameters on generated entropy, hydrodynamic performance and heat transfer characteristics of a tangential micro-heat sink (TMHS) was numerically investigated in this research. Results indicated that considerable heat transfer enhancement is possible when using Al 2O 3-water nanofluids as coolant and clearly the enhancement improves with increasing particles concentration and decreasing particles size. However, using nanofluid has also induced drastic effects on the pumping power that increases with particles volume fraction and Reynolds number. Finally, it was found that generated total entropy decreases with increasing volume fraction and Reynolds number and decreasing particles size. © 2012 Elsevier Ltd. All rights reserved.
Seyf H.R.,Islamic Azad University at Karaj |
Feizbakhshi M.,Sharif University of Technology
International Journal of Thermal Sciences | Year: 2012
Numerical investigation on the application of nanofluids in Micro-Pin-Fin Heat Sinks (MPFHSs) has been presented in this paper. To investigate flow and heat transfer behavior in MPFHS the three-dimensional steady Navier-Stokes and energy equations were discretized using a finite volume approach and have been solved iteratively, using the SIMPLE algorithm. DI-water is used as a base coolant fluid while the nanoparticles used in the present study are CuO nanoparticles with mean diameters of 28.6 and 29 nm and Al 2O 3 nanoparticles with mean diameters of 38.4 and 47 nm. The results show that (i) a significant enhancement of heat transfer in the MPFHS due to suspension of CuO orAl 2O 3 nanoparticles in the base fluid in comparison with pure water, (ii) enhancement of heat transfer is intensified with increasing volume fraction of nanoparticles and Reynolds number, (iii) increasing volume fraction of nanoparticles which is responsible for higher heat transfer performance leads to higher pressure drop or Euler number in MPFHS but the enhancements are small, especially for lower particle volume fractions, (iv) with decreasing particle diameters the Nusselt number increases for Al 2O 3-water nanofluid while the trend is reverse for CuO-water nanofluid. © 2012 Elsevier Masson SAS. All rights reserved.
Malvandi A.,Islamic Azad University at Karaj |
Ganji D.D.,Babol Noshirvani University of Technology
International Journal of Thermal Sciences | Year: 2014
The current study is a theoretical investigation of the laminar flow and convective heat transfer of alumina/water nanofluid inside a circular microchannel in the presence of a uniform magnetic field. A modified two-component four-equation nonhomogeneous equilibrium model was employed for nanofluids, which fully accounted for the effect of the nanoparticle volume fraction distribution. Because of the microscopic roughness in circular microchannels and also the non-adherence of the fluid-solid interface in the presence of nanoparticle migration, known as slip condition, the Navier's slip boundary condition is considered at the walls. The results indicated that nanoparticles migrate from the heated walls (nanoparticles depletion) towards the core region of the microchannel (nanoparticles accumulation) and construct a non-uniform nanoparticles distribution. The ratio of the Brownian to thermophoretic diffusivities (NBT) has relatively significant effects both on the distribution of the nanoparticles and the convective heat transfer coefficient of nanofluids. It was further observed that for smaller nanoparticles, the nanoparticle volume fraction is more uniform and abnormal variations in the heat transfer rate vanish. Moreover, in the presence of the magnetic field, the near wall velocity gradients increase, enhancing the slip velocity and thus the heat transfer rate and pressure drop increase. © 2014 Elsevier Inc. All rights reserved.
Farzipoor Sean R.,Islamic Azad University at Karaj
International Journal of Advanced Manufacturing Technology | Year: 2010
In traditional models of data envelopment analysis it is assumed that decision making units do not have dual-role factors. This paper proposes a model for selecting third-party reverse logistics (3PL) provider in the presence of multiple dual-role factors. A numerical example demonstrates the application of the proposed method. © 2009 Springer-Verlag London Limited.