Browsing by Author "Sajadi, S. Mohammad"

Now showing 1 - 13 of 13

Citation - WoS: 18
Citation - Scopus: 19
Effects of Brownian motions and thermophoresis diffusions on the hematocrit and LDL concentration/diameter of pulsatile non-Newtonian blood in abdominal aortic aneurysm
(Elsevier, 2021) Abbasi, Mohammad; Esfahani, Amin Nadimian; Golab, Ehsan; Golestanian, Omid; Ashouri, Nima; Sajadi, S. Mohammad; Karimipour, A.; 56389
LDL concentration is believed to be responsible for plaque formation that leads to atherosclerotic cardiovascular disease. We conducted this study to investigate the effects of hematocrits and LDL diameters on LDL concentration on the wall of an abdominal aortic aneurysm (AAA). The blood flow was considered to be a pulsatile and non-Newtonian flow whose viscosity was a function of hematocrits and strain rate. Lumen, Brownian, and thermophoresis diffusions were analyzed in LDL concentration. The results demonstrated that adding thermophoresis diffusion increases LDL concentration. Moreover, among three types of LDLs, including small LDLs, intermediate LDLs, and large LDLs, small LDLs were the ones with the highest concentration at the wall of the aneurysm. Furthermore, the effects of vorticity on diffusions were examined; it could be noted that the maximum Brownian diffusion appeared in vorticity places. Our results indicated that Brownian diffusion declines as hematocrit reaches 45% whereas thermophoresis diffusion increases. The current simulation investigated the effects of hematocrits, vorticity, Brownian, and thermophoresis diffusions on LDL concentration on the wall. Three types of LDL were taken into account for investigation of the effects of the diameter and reference concentration on LDL concentration. The outcomes of this study could be summarized as the following: the maximum amount of the wall shear stress appeared at 0.2T and at the upstream end of the AAA; moreover, thermophoresis diffusion increased small LDL concentration by 26% on the wall for hematocrit 45%.
Citation - WoS: 32
Citation - Scopus: 32
Flat sheet direct contact membrane distillation study to decrease the energy demand for solar desalination purposes
(Elsevier, 2022) Tlili, Iskander; Baleanu, Dumitru; Sajadi, S. Mohammad; Baleanu, Dumitru; Ghaemi, Ferial; 56389
One of the most important feature of any desalination technology is energy consumption of producing fresh water specially when its energy source is solar energy. To improve this, study of various input parameters and determination of their effects on energy consumption would be essential. In this paper, a one-dimensional model is used to investigate the effects of different operational and geometrical parameters on energy consumption of flat sheet direct contact membrane distillation (DCMD) for solar desalination purposes. It is assumed that the energy consumption of DCMD includes of electrical to drive electro pumps and thermal energy. In this regard, variation of each parameter is studied at different inlet bulk flow temperatures difference (TD). Results show that specific energy consumption (EC) of DCMD is improved by increasing inlet bulk flow temperature difference regardless of any parameter variations. Nevertheless, increasing of Inlet mass flow rate and decreasing inlet salinity are also enhanced specific energy consumption. For geometrical parameters, increasing length, width and channel height increase energy consumption while increasing membrane porosity and thickness do the opposite. It is also observed that the electrical energy incorporates a very small portion of whole energy consumption in most cases but when small channel width or height is selected it becomes significant. Since electrical energy is more expensive than thermal energy, careful channel geometry design must be done.
Citation - WoS: 5
Citation - Scopus: 5
Improve the heat exchanger efficiency via examine the Graphene Oxide nanoparticles: a comprehensive study of the preparation and stability, predict the thermal conductivity and rheological properties, convection heat transfer and pressure drop
(Springer, 2022) Ranjbarzadeh, Ramin; Baleanu, Dumitru; Akhgar, Alireza; Taherialekouhi, Roozbeh; D'Orazio, Annunziata; Sajadi, S. Mohammad; Ghaemi, Ferial; Baleanu, Dumitru; 56389
In this research, the effect of using GO/ water nanofluid as a coolant fluid in an isothermal heat transfer system was studied. At first, to evaluate the atomic bond, chemical, and surface structure of the nanoparticles, XRD-FTIR and FESEM tests were used. Two-step method was used to prepared nanofluid then DLS test was utilized to examine the stability of the nanofluid. Thermal conductivity and the dynamic viscosity were measured experimentally from 25 to 75 celcius and volume fractions of 0-0.15%. The maximum improvement in thermal conductivity is 11.2% at 0.15% and 75 celcius. Also The dynamic viscosity increased. The validity and uncertainty of the test results were examined. The heat transfer and turbulent flow of the nanofluid under a constant temperature boundary condition were investigated between 6000 and 18,700 Reynolds numbers. Various parameters such as the pressure drop, friction factor, convection heat transfer coefficient, and Nusselt number of the turbulent flow were evaluated. According to the results, the greatest increase in the convection heat transfer coefficient of the nanofluid was 34.7% compared to that of the base fluid. Also, the greatest enhancement in the friction factor was 9.64%. It can be stated that the improvement of the convection heat transfer coefficient dominantly affects the pressure drop so this nanofluid can be used as a coolant fluid in industrial systems.
Citation - WoS: 16
Citation - Scopus: 17
Improve thermal performance of Simulated-Body-Fluid as a solution with an ion concentration close to human blood plasma, by additive Zinc Oxide and its composites: ZnO/Carbon Nanotube and ZnO/Hydroxyapatite
(Elsevier, 2021) Abidi, Awatef; Baleanu, Dumitru; Jokar, Zahra; Allahyari, Seyedmahmoodreza; Sadigh, Fereshteh Kolahi; Sajadi, S. Mohammad; Firouzi, Payam; Karimipour, Arash; 56389
Nanofluid is a suspension of Nanoparticles in a basefluid. Typical fluids carry less heat transfer than nanofluids. However, the perception of heat transfer for bio-nanomaterials can help scientists in fields as implant coatings, nano-robotics, etc. In this research, heat transfer of Zinc Oxide (ZnO) in Simulated-Body-Fluid (SBF) was studied. Then, heat transfer of ZnO/Carbon Nanotube and ZnO/ Hydroxyapatite in SBF was studied. After that, the results were compared experimentally and numerically. The numerical optimization was done by Artificial Neural Network and Fuzzy system. To make the ZnO/SBF mono nanofluid, first, five volume fractions of 0.2-1.0% were made. Also, ZnO-HA/SBF and ZnO-CNT/SBF hybrid nanofluid samples were made in the same volume fractions, individually. After that, heat transfer was measured at temperatures of 20-50 degrees C. Also, Artificial Neural Networks with Levenberg-Marquardt and Orthogonal-Distance-Regression algorithms were modeled. Then, Fuzzy system was employed to train the data with the least uncertainty. Results showed that in comparison with ZnO-SBF nanofluid, the effects of adding Hydroxyapatite and Carbon Nanotube are heat transfer enhancement of -16.73% and +17.49% at 1.0 vol% and 50 (degrees C), individually. Also, computational process can be employed to optimize the "nanofluid's heat transfer measurement" for cost-reduction in experiments. (C) 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 9
Lattice Boltzmann method to study free convection and entropy generation of power-law fluids under influence of magnetic field and heat absorption/generation
(Springer, 2022) Nemati, Mohammad; Baleanu, Dumitru; Sefid, Mohammad; Sajadi, S. Mohammad; Ghaemi, Ferial; Baleanu, Dumitru; 56389
The aim of this present work assesses heat transfer and entropy generation arising from free convection of power-law fluids in a trapezoidal chamber under the effect of uniform and non-uniform magnetic field with heat absorption/generation by using LBM. The impact of Rayleigh number (10(3), 10(4) and 10(5)), wall slope (11.5 degrees, 26.5 degrees and 38.5 degrees), power-law index (0.75, 1.0 and 1.25), Hartmann number (0, 15, 30 and 45), type of magnetic field applied (uniform and non-uniform) with heat absorption/generation (- 10, - 5, 0, + 5 and + 10) on fluid flow and heat transfer characteristics has been evaluated. By enhancement of the Rayleigh number and decreasing wall slope of the chamber, the flow strength, the rate of heat transfer and entropy generation increase and the effect of the magnetic field becomes more remarkable. By applying a magnetic field non-uniformly, the flow strength and heat transfer rate can be grown to about 25% and 15%, respectively. At higher Hartmann and Rayleigh numbers, the effect of changing the type of magnetic field applied is more notable. By increasing the heat absorption/generation coefficient, the average Nusselt number decreases and the effect of the magnetic field increases. In the heat generation mode, the total entropy generation increases with increasing Hartmann number, while in the heat absorption mode, the opposite effect was obvious. A salient and distinctive feature of the present work compared to previous studies is the application of non-uniform magnetic field (specific type of application) in the presence of heat absorption/generation for non-Newtonian fluids, which is not researched.
Citation - WoS: 4
Citation - Scopus: 3
Numerical analysis of the effect of hot dent infusion jet on the fluid flow and heat transfer rate through the microchannel in the presence of external magnetic field
(Springer, 2022) Jalali, Esmaeil; Baleanu, Dumitru; Sajadi, S. Mohammad; Ghaemi, Ferial; Baleanu, Dumitru; 56389
In this work, the nanofluid flow inside a microchannel with serrated injection jet on the upper wall of microchannel and using magnetic field with intensity of 0-40 Hartman were surveyed. The lower microchannel wall with jet injection racks has a constant temperature, but the upper microchannel wall is insulated among injection jets. Applying dented mode for injection jets was performed to enhance heat transfer. This research was performed for Reynolds numbers 10-50 and B = 0.01, 0.05, and 0.1 and for volume fraction of 0-6% water/Al2O3. The results indicated that the higher the height of dents was, the higher the heat transfer occurred.
Citation - WoS: 33
Citation - Scopus: 34
Numerical and experimental analysis of temperature distribution and melt flow in fiber laser welding of Inconel 625
(Springer London Ltd, 2022) Tlili, Iskander; Baleanu, Dumitru; Baleanu, Dumitru; Sajadi, S. Mohammad; Ghaemi, Ferial; Fagiry, Moram A.; 56389
In these days, laser is a useful and valuable tool. Low input heat, speed, accuracy, and high controllability of laser welding have led to widespread use in various industries. Nickel-based superalloys are creep-resistant materials used in high-temperature conditions. Also, these alloys have high strength, fatigue, and suitable corrosion resistance. Inconel 625 is a material that is strengthened by a complex deposition mechanism. Therefore, the parameters related to laser welding affect the microstructure and mechanical properties. Therefore, in this study, the effect of fiber laser welding parameters on temperature distribution, weld bead dimensions, melt flow velocity, and microstructure was investigated by finite volume and experimental methods. In order to detect the temperature history during continuous laser welding, two thermocouples were considered at a distance of 2 mm from the welding line. The heat energy from the laser beam was modeled as surface and volumetric heat flux. The results of numerical simulation showed that Marangoni stress and buoyancy force are the most important factors in the formation of the flow of liquid metal. Enhancing the laser power to 400 W led to the expansion of the width of the molten pool by 1.44 mm, which was in good agreement with the experimental results. Experimental results also showed that increasing the temperature from 500 degrees C around the molten pond leads to the formation of a coarse-grained austenitic structure.
Citation - WoS: 4
Citation - Scopus: 4
Solar radiation effect on PCM performance in the building applications: The collector energy-saving potential using CF-MWCNTs and CF-GNPs
(Elsevier, 2022) Chen, Liangliang; Baleanu, Dumitru; Sajadi, S. Mohammad; Liu, Fenghua; Alrabaiah, Hussam; Aldabesh, Abdulmajeed; Baleanu, Dumitru; 56389
In this study, a hot and desert location with an annual temperature of 27.1 ? and a very high radiation intensity of 2143 kWh/m(2), a solar system (ES) was approved to provide building cooling necessities. The cooling system, by connecting to the solar system, supplied a part of its required energy. The outer layer of the building walls was equipped with PCM (SP-21EK) with a melting point of 21-23 and latent heat of 170 kJ/kg. In the solar system, water was filled to absorb energy and then a combination of CF-MWCNTs and CF-GNPs nanoparticles were injected to the solar system to improve effectiveness. In July, when the radiation intensity was very high, the combination of PCM and SC condensed energy consumption (EC) by up to 46.48%. The presence of CF-MWCNTs and CF-GNPs at 0.1 wt% was useful in all conditions (2, 3 and 4 lit/min). In this case, the EC reduction was in the range of 360 to 1026 kWh. At lower concentrations, the nanoparticles not only were not worthwhile, in some cases increased EC by 937 kWh.
Citation - WoS: 13
Citation - Scopus: 15
The effect of sedimentation phenomenon of the additives silver nano particles on water pool boiling heat transfer coefficient: A comprehensive experimental study
(Elsevier, 2022) Baleanu, Dumitru; Sajadi, S. Mohammad; Abu-Hamdeh, Nidal H.; Bezzina, Smain; Abdollahi, Ali; Karimipour, Arash; Baleanu, Dumitru; 56389
Nowadays, the increase in the number of nanoparticles in base fluids is considered as one of the most significant causes of change in thermodynamic properties and boiling heat transfer coefficient. Hence, the present study aims to examine the effects of different concentrations of silver nanoparticles on pool boiling inside deionized water. Five different nanoparticle concentrations were tested, namely (0.2, 0.4, 0.6, 0.8, 1) gr/lit. The nanoparticles were synthesized using the two-step method in an aqueous base fluid. A magnetic stirrer was first used to suspend the nanoparticles, and then the stabilization was performed using an ultrasonic stirrer. The average diameter of the nanoparticles is approximately 20 nm, and the stability results indicate that the nanofluids are highly stable. The stability results from the DLS test show that changing the pH of the base fluid by 9 at a concentration of 0.4 gr/lit results in stability of -40 mV. The boiling results of the deionized water were recorded in three steps and were compared to the Rohsenow curve. The variations were very similar to the Rohsenow curve, and the change in the wall superheat and the shifting of the curve can be due to the different conditions of the experimental apparatus. The results indicate that adding silver nanoparticles leads to a decrease in the boiling heat transfer coefficient provided that the roughness parameter is smaller than or equal to unity. Increasing the concentration can reduce the deviation in the boiling heat transfer coefficient at low heat fluxes and increase it at high heat fluxes. Furthermore, boiling heat transfer on sedimentation surfaces was examined in three sedimentation steps. The results show that an increase in sedimentation and a decrease in the roughness parameter cause a reduction in the boiling heat transfer coefficient. (C) 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 2
Citation - Scopus: 3
The investigation of energy management and atomic interaction between coronavirus structure in the vicinity of aqueous environment of H2O molecules via molecular dynamics approach
(Elsevier, 2021) Guo, Hui-Hui; Baleanu, Dumitru; Bajuri, Mohd Yazid; Alrabaiah, Hussam; Muhammad, Taseer; Sajadi, S. Mohammad; Ghaemi, Ferial; Karimipour, Arash; 56389
The coronavirus pandemic is caused by intense acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Identifying the atomic structure of this virus can lead to the treatment of related diseases in medical cases. In the current computational study, the atomic evolution of the coronavirus in an aqueous environment using the Molecular Dynamics (MD) approach is explained. The virus behaviors by reporting the physical attributes such as total energy, temperature, potential energy, interaction energy, volume, entropy, and radius of gyration of the modeled virus are reported. The MD results indicated the atomic stability of the simulated virus significantly reduced after 25.33 ns. Furthermore, the volume of simulated virus changes from 182397 angstrom(3) to 372589 angstrom(3) after t = 30 ns. This result shows the atomic interaction between various atoms in coronavirus structure decreases in the vicinity of H2O molecules. Numerically, the interaction energy between virus and aqueous environment converges to -12387 eV and -251 eV values in the initial and final time steps of the MD study procedure, respectively. (C) 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 7
Citation - Scopus: 8
The investigation of Fe3O4 atomic aggregation in a nanochannel in the presence of magnetic field: Effects of nanoparticles distance center of mass, temperature and total energy via molecular dynamics approach
(Elsevier, 2022) Liu, Xinglong; Baleanu, Dumitru; Fagiry, Moram A.; Sajadi, S. Mohammad; Almasri, Radwan A.; Karimipour, Arash; Li, Zhixiong; Ghaemi, Ferial; 56389
The computational procedure was utilized to explain the size effect of Fe3O4 nanoparticles on atomic behavior and phenomena of nanoparticles accumulation in nanochannel of ideal platinum (Pt) and the external magnetic field. Argon (Ar) atoms were considered as the base liquid, and the molecular dynamics procedure was utilized in this investigation. We utilized the Lennard-Jones potential to interact between the particles, whereas the nanochannel and nanoparticles structures were simulated. To compute the atomic manner, the quantities of nanoparticles distance center of mass, and the aggregation duration were presented. The outcomes implied that the nanoparticles size had a significant role in the accumulation. As the nanoparticles' size increased, the accumulation time of nanoparticles reached to 1.29 ns. Also, the outer magnetic field could severly postpone this event. (C) 2021 Published by Elsevier B.V.
Citation - WoS: 8
Citation - Scopus: 8
The Molecular dynamics study of atomic Management and thermal behavior of Al-Water Nanofluid: A two phase unsteady simulation
(Elsevier, 2021) Shi, Yunhong; Allahyari, Seyedmahmoodreza; Sajadi, S. Mohammad; Alazwari, Mashhour A.; Firouzi, Payam; Abu-Hamdeh, Nidal H.; Karimipour, Arash; 56389
Molecular Dynamic (MD) approach is used to describe the temperature and pressure effects on the Al nanoparticles aggregation process in the aqueous environment of water as the base liquid. For this goal, various physical parameters like total energy, temperature, aggregation time, and total energy of the simulated structures, are reported. The results show that the aggregation process enlarges by the ratio of temperature and pressure. By atomic mobility increasing, the Al nanoparticles collide with each other in a shorter simulation time. Numerically, by temperature increases from 300 K to 350 K, the aggregation time decreases from 1.33 ns to 1.18 ns. Furthermore, aggregation time increases to 1.99 ns by more pressure to 5 bar. (C) 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 6
Water molecules adsorption by a porous carbon matrix in the presence of NaCl impurities using molecular dynamic simulation
(Elsevier, 2022) Baleanu, Dumitru; Sajadi, S. Mohammad; Abu-Hamdeh, Nidal H.; Bezzina, Smain; Kalbasi, Rasool; Karimipour, Arash; Baleanu, Dumitru; 56389
Today, one of the most important issues in human societies is environmental protection and material recycling. Due to their high surface area and high porosity, porous carbon can be used in different fields of catalytic, recycling, separation, storage, drug delivery, etc. In the present study, the process of adsorption of H2O molecules in the presence of NaCl impurities by a porous carbon matrix has been investigated using the molecular dynamics method. The results show that the process of adsorption of H2O molecules by the porous carbon matrix decreases with increasing impurities in atomic structures. Increasing impurities in atomic structures disrupt the process of adsorption of H2O molecules by the porous carbon matrix. Numerically, by increasing the impurity to 20%, 56% of the H2O molecules were adsorbed on the simulated atomic matrix. Also, the increase in impurities in atomic structures increases the adsorption process of disturbing atoms by the porous carbon matrix. By increasing the impurity to 20%, 9% of the disturbing atoms were adsorbed on the simulated atomic matrix. Finally, by performing this simulation and investigating the effect of impurities on H2O absorption by porous carbon structures, it is expected that an optimal process can be designed for water treatment, which is one of the most important challenges of human societies. (C) 2021 Elsevier B.V. All rights reserved.