Browsing by Author "Nasajpour-Esfahani, Navid"

Now showing 1 - 17 of 17

Citation Count: 0
Bonding properties of Al/Sn/Al laminates fabricated via electrically press bonding process
(Elsevier, 2024) Daneshmand, Saeed; Salahshour, Soheıl; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Salahshour, Soheil; Hekmatifar, M.; Nasajpour-Esfahani, Navid
In the late 1980s, electrically assisted press bonding gained attention in the semiconductor industry due to its ability to improve bond quality and reliability. This bonding method has several advantages, including improved bond strength, reduced bonding time, and the ability to bond materials that are traditionally challenging to bond. This connection method is commonly used in applications where high band strength, reliability, and electrical conductivity are critical, such as microelectronics manufacturing, semiconductor devices, and advanced packaging technologies. In this study, AA1100 bars were connected using an electrically assisted press connection process at current levels of 100A, 200A and 300A. Poor bond strength is an important drawback in bonding processes. Therefore, to solve this problem, Sn particles were used as a finishing process and filler metal to increase the bond strength of aluminum sheets during electric press joining. AA1100 bars were produced with different weight percentages (wt%) of Sn particles as interlayer filler at different levels of electric current. The results reveal that increasing the level of electric current and the weight percentage of Sn leads to stronger bond strength. In this study, a scanning electron microscope (SEM) is used to check the quality of the bond. It is worth mentioning that the analysis of the exfoliation surface by SEM is performed on the samples after the peeling test to check the quality of the bond. In addition, the findings reveal that the bond strength improves with Sn content and higher current levels due to the Joule heating effect in the electrical press bonding process.
Citation Count: 0
Changes in mechanical properties of copper-silver matrix welded by the iron blade by increasing initial pressure: A molecular dynamics approach
(Elsevier, 2024) Ayadi, Badreddine; Salahshour, Soheıl; Sajadi, S. Mohammad; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Esmaeili, Shadi; Elhag, Ahmed Faisal Ahmed
Atomic investigation of many common phenomena can be included as interesting achievements. Using these achievements makes it possible to design promising structures for various actual applications. The current research describes the mechanical performance of Ag and Cu samples after welding at various initial pressures. For this purpose, the Molecular Dynamics (MD) approach is used via the LAMMPS package. Technically, MD simulations are done in 2 main steps. Firstly, the atomic stability of welded Ag-Cu samples is described at various initial conditions (initial pressure). Then, tension test settings are implemented in equilibrated systems. The MD outputs indicate that the physical stability of the welded samples was altered by changing the initial pressure between 1 and 10 bar. Simulation results predict that the mechanical resistance of atomic samples decreases by enlarging the initial pressure. Numerically, the ultimate strength of the Ag-Cu matrixes decreases from 1.424 MPa to 1.241 MPa by increasing the initial pressure from 1 bar to 10 bar, respectively. This mechanical performance arises from atomic disorder created inside samples. So, it is expected that initial condition changes affect the atomic evolution of welded metallic samples, and this phenomenon should be considered in the design of mechanical structures in industrial cases.
Citation Count: 0
Combining neutral scalar and isothermal Shan-Chen lattice Boltzmann method to simulate droplet placement on a wall in isothermal and non-isothermal states
(Elsevier, 2024) Liu, Yanan; Salahshour, Soheıl; Sajadi, S. Mohammad; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Zarringhalm, Majid; Rahmani, Amin
Background: In the current article, two-phase thermal fluxes are created by combining the thermal model of the neutral scalar model with the two-phase Shan-Chen model of the lattice Boltzmann method (LBM). Methods: The different intermolecular powers for the isothermal Shan-Chen model show how a droplet would be placed on a wall. By raising the droplet intermolecular power parameter, the surface area increases and becomes wet. Next, the isothermal Shan-Chen method and the neutral scalar method are combined to investigate multiphase thermal problems. The droplet placement on the hot wall is therefore done at relatively high Rayleigh numbers. By raising the Rayleigh number, the isothermal lines within the droplet's interior gradually become less ascending and less descending until they eventually achieve a uniform state when it is placed against a hot wall. Additionally, the channel's Rayleigh-Benard convective heat transfer is enhanced by increasing the Rayleigh number. Significant findings: Natural convection in the enclosures can be used in solar collectors. As the Rayleigh number increases, the average Nusselt number (Nuavg) rises as would be expected. The results demonstrate that LBM is a practical method for simulating multi-phase thermal flows.
Citation Count: 0
The effect of initial pressure on the thermal behavior of the silica aerogel/PCM/CuO nanostructure inside a cylindrical duct using molecular dynamics simulation
(Elsevier, 2024) Gao, Yuanfei; Salahshour, Soheıl; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Baghaei, Sh.
Amidst escalating fuel expenses and growing concerns over greenhouse gas pollution, the adoption of renewable alternative energy sources has become increasingly imperative. In response, scientists are fervently dedicated to identifying energy-saving solutions that are readily adaptable. Notably, silica aerogels have demonstrated remarkable efficacy in temperature management under both hot and cold conditions, while phase change materials are renowned for their capacity to store thermal energy. The study examines the effect of initial pressure on the thermal performance of silica aerogel/PCM/CuO nanostructure in a cylindrical duct. This was investigated using MD simulations and the LAMMPS software. The study will investigate several elements, such as density, velocity, temperature patterns, heat flux, thermal conductivity, and charge time or discharge time of the simulated structure. According to the results, with an increase in the initial pressure, the maximum density increases from 0.0838 atom/angstrom 3 to 0.0852 atom/angstrom 3, and the maximum velocity decreases from 0.0091 angstrom/fs to 0.0081 angstrom/fs. Also, the findings show that, by increasing the initial pressure, the temperature decreases from 931.42 K to 895.63 K, and thermal conductivity and heat flux decrease to 1.56 W/m.K and 56.66 W/m2 with increasing the initial pressure to 5 bar. Finally, the results show that charging time increases to 6.34 ns at 5 bar. The increase in charging time with increasing initial pressure may be attributed to the reduced mobility of particles within the structure as a result of the higher pressure. The findings of this study can help for a better understanding of energy-saving solutions, advanced thermal management systems, and the design of efficient energy storage technologies tailored to specific pressure-related operating conditions.
Citation Count: 2
Experimental study of phase change material (PCM) based spiral heat sink for the cooling process of electronic equipment
(Elsevier, 2024) Wang, Yu; Salahshour, Soheıl; Sajadi, S. Mohammad; Smaisim, Ghassan Fadhil; Hadrawi, Salema K.; Nasajpour-Esfahani, Navid; Toghraie, D.
Today, every device that a person uses depends on electronic equipment, frequent and long-term use of it causes to heat up and as a result, slow down the speed and performance of that device. In more important and sensitive equipment such as medical equipment, slow speed and reduced performance cause irreparable damage. Therefore, to cool these devices, their internal electronic equipment must be cooled. In studies by others, the simultaneous use of several phase change materials and airflow in the form of layer-by-layer contact was usually less studied. In this study, using CNC machining, a heatsink consisting of 2 spirals was produced. In the first spiral, PCM Paraffin Wax with different volume percentages and in the second spiral, the presence or absence of forced airflow in heat transfer rate 2.9 W to 3.7 W was tested with a step of 0.4 W and the results were that by adding %50 PCM and adding 100 % PCM to the system, its performance increases by 7.19 % and 44.91 %, respectively, which shows using the maximum volume capacity of PCM increases efficiency. Also, by adding forced airflow to the system, its performance has increased by 7.71 %. It can be said that if the forced airflow in the system is used layer by layer, it prevents the heat from concentrating in certain parts of the heatsink and the circuit, which results in the same heating of the whole system and the heat is evenly distributed throughout the heatsink.
Citation Count: 1
Investigating the effect of external heat flux on the thermal behaviour of hybrid paraffin-air heat sink: A molecular dynamics approach
(Elsevier, 2023) Wang, Ke; Salahshour, Soheıl; Alizadeh, As'ad; Al-Rubaye, Ameer H.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Hekmatifar, M.
One of today's concerns regarding energy storage units is the low rate of storage and release of thermal energy and, as a result, the efficiency loss in these units. Subsequently, different strategies are utilized to solve this concern, such as using phase change materials (PCMs) and nanostructures. The background is the low storage and release rate of thermal energy in energy storage units, which leads to efficiency loss. This issue concerns many applications, including energy storage in buildings, vehicles, and electronic devices. This study aims to investigate the effect of external heat flux (EHF) on the thermal efficiency of a specific heat sink by employing molecular dynamics (MD) simulation. After ensuring the simulated atomic structures are stable, EHF is applied to see how it affects the thermal behaviour of the combination. The obtained results show that by increasing the EHF applied to the prototype, the thermal behaviour of the structure improves. So, with the increase of EHF from 0.1 W/m2 to 0.5 W/m2, the heat flux and thermal conductivity (TC) increase from 212.27 W/m2 to 317.90 W/mK to 286.71 W/m2 and 340.03 W/mK. The findings significantly affect energy storage unit efficiency and can inform future research and development efforts.
Citation Count: 0
Investigating the effect of the number of layers of the atomic channel wall on Brownian displacement, thermophoresis, and thermal behavior of graphene/water nanofluid by molecular dynamics simulation
(Elsevier, 2024) Guo, Xinwei; Salahshour, Soheıl; Alizadeh, Asad; Keivani, Babak; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Sabetvand, Rozbeh
Nanofluids (NFs) are nanoscale colloidal suspensions containing dense nanomaterials. They are two-phase systems with solid in liquid phase. Due to their high thermal conductivity, nano -particles increase the thermal conductivity (TC) of base fluids, one of the basic heat transfer parameters, when distributed in the base fluids. The present research investigates the thermal behavior, Brownian motion, and thermophoresis of water/graphene NF affected by different numbers of atomic wall layers (4, 5, 6 and 7) by molecular dynamics (MD) simulation. This investigation reports changes in heat flux (HF), TC, average Brownian displacement, and ther-mophoresis displacement. By raising the number of atomic wall layers from 4 to 7, the average Brownian displacement and thermophoresis displacement increase from 3.06 angstrom and 23.88 angstrom to 3.62 and 25.05 angstrom, respectively. Increasing the number of layers due to the decrease in temper-ature increases the temperature difference between the hot and cold points along the channel. It increases the Brownian motion and the maximum temperature. Additionally, by raising the atomic layers of the channel wall, the values of HF and TC increase from 39.54 W/m2 and 0.36 W/mK to 41.18 W/m2 and 0.42 W/mK after 10 ns, respectively. The temperature rose from 1415 to 1538 K. These results are useful in different industries, especially for improving the thermal properties of different NFs.
Citation Count: 0
Investigating the initial pressure effect on Brownian displacement, thermophoresis, and thermal properties of graphene/ water nanofluid by molecular dynamics simulation
(Elsevier, 2024) Ren, Jiaxuan; Salahshour, Soheıl; Sajadi, S. Mohammad; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Sabetvand, Rozbeh
The concept of nanofluid includes suspensions containing nanoparticles, metallic and non-metallic materials. Nanofluids have many potentials in different environments and conditions that make them exist in industries and food industries. Considering their high thermal conductivity, the nanoparticles increased the fluid's thermal conductivity, one of the basic heat transfer parameters, when distributed in the base fluid. The present research investigated the thermal properties, Brownian motion, and thermophoresis of water/ graphene nanofluid affected by different ratios of initial pressure (1, 2, 3 and 5 bar) by molecular dynamics simulation. This study reported the changes in heat flux, thermal conductivity, average Brownian displacement, and thermophoresis. The results depict that by increasing the initial pressure from 1 to 5 bar, average Brownian displacement and thermophoresis values decrease from 06.3 and 23.88 to 2.91 and 23.53 angstrom, respectively. Also, by raising the initial pressure (1 to 5 bar), the heat flux and thermal conductivity after 10 ns decrease from 39.54 and 0.36 to 35.12 W/m2 and 0.28 W/m.K, and the maximum temperature reduces from 1415 K to 1033 K. These results can be useful in different industries, especially for improving the thermal properties of different nanofluids.
Citation Count: 0
The nano-pumping process of C20 molecules from carbon nanotube at the different external electric fields and atomic defects: A molecular dynamics approach
(Elsevier Science Sa, 2024) Niu, Haichun; Salahshour, Soheıl; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Salahshour, Soheil; Nasajpour-Esfahani, Navid; Sabetvand, Rozbeh
Today, carbon nanotubes are involved in many medical types of research, such as biosensors and drug delivery. These nanotubes do not pose a problem for the body regarding toxicity to body cells and triggering the immune system. Nanotubes have also been proven to increase solubility and the possibility of targeted drug delivery. This study used molecular dynamics simulation to examine the nano-pumping process of the C20 molecule in carbon nanotubes at the different electric fields and atomic defects. The process of C20 molecule nano-pumping was examined by examining the changes in kinetic energy, potential energy, entropy, stress, temperature, and in-ternal energy changes. In the following, the stress on the atomic structure was calculated. For this purpose, constant electric fields with the magnitudes of 0.01, 0.02, 0.03, 0.05, and 0.1 V/angstrom are used for the atomic structure. The results show that the nano-pumping time of the C20 molecule in the carbon nanotubes increases by increasing the electric field magnitude. The results also revealed that the kinetic energy in the structure decreased by increasing the electric fields, and the potential energy increased. As the potential energy increased in the atomic structure, the stability increased. Therefore, it is expected that the C20 molecule nano-pumping time will increase. The following examined the effect of atomic defects in an electric field with a magnitude of 0.01 V/angstrom. For this purpose, the atomic defects with magnitudes of 1 %, 2 %, 3 %, and 4 % were used for carbon nanotubes. The results revealed that increasing the atomic defects increased the C20 molecule nano-pumping time. Furthermore, the stress on the structure increased by increasing the atomic defects.
Citation Count: 0
A new model for viscosity prediction for silica-alumina-MWCNT/Water hybrid nanofluid using nonlinear curve fitting
(Elsevier - Division Reed Elsevier india Pvt Ltd, 2024) Qu, Meihong; Salahshour, Soheıl; Alizadeh, As'ad; Eftekhari, S. Ali; Nasajpour-Esfahani, Navid; Zekri, Hussein; Toghraie, Davood
One of the most crucial concerns is improving industrial equipment's ability to transmit heat at a faster rate, hence minimizing energy loss. Viscosity is one of the key elements determining heat transmission in fluids. Therefore, it is crucial to research the viscosity of nanofluids (NF). In this study, the effect of temperature (T) and the volume fraction of nanoparticles (phi) on the viscosity of the silica-alumina-MWCNT/Water hybrid nanofluid (HNF) is examined. In this study, a nonlinear curve fitting is accurately fitted using MATLAB software and is used to identify the main effect, extracting the residuals and viscosity deviation of these two input variables, i.e., temperature (T = 20 to 60 C-degrees) and volume fraction of nanoparticles (phi = 0.1 to 0.5 %). The findings demonstrate that the viscosity of silica-alumina-MWCNT/ Water hybrid nanofluid increases as the phi increases. In terms of numbers, the mu nf rises from 1.55 to 3.26 cP when the phi grows from 0.1 to 0.5 % (at T = 40 C-degrees). On the other hand, the mu nf decreases as the temperature was increases. The mu(nf) of silica-alumina-MWCNT/ Water hybrid nanofluid reduces from 3.3 to 1.73 cP when the temperature rises from 20 to 60 C-degrees (at phi = 0.3 %). The findings demonstrate that the mu nf exhibits greater variance for lower temperatures and higher phi.
Citation Count: 1
A numerical study of carbon doping effect on paraffin-reinforced silica aerogel mechanical properties: A molecular dynamics approach
(Elsevier, 2023) Zhang, Wei; Salahshour, Soheıl; Alizadeh, As'ad; Nasajpour-Esfahani, Navid; Hekmatifar, Maboud; Sabetvand, Roozbeh; Toghraie, D.
Aerogels are different types of porous and solid materials that exhibit a strange set of extraordinary material properties. Aerogels have great potential for use in the fields of heat, sound, electronics, and especially thermal insulation. This paper investigates the influence of carbon doping concentration on the mechanical properties of paraffin-reinforced silica aerogel (PRSA). To do this investigation, Young's module (YM), stress-strain curve, and ultimate strength (US) values at various carbon-doped particles of 1 to 10 % were reported by molecular dy-namics (MD) simulation. The results show that the PRSA, under the influence of carbon doping, has dual per-formance. To be more precise, by adding the amount of carbon doped from 1 to 3 %, the US and YM of the PRSA rose from 329.96 and 1137.20 MPa to 353.73 and 1268.44 MPa. In other words, the mechanical strength of the PRSA increases in a limited ratio. However, by increasing carbon doping from 3 to 10 %, the US and YM of the PRSA reduced to 306.233 and 1041.88 MPa, respectively. So, it is expected that the mechanical behavior of the PRSA matrix to be manipulated with carbon doping for actual applications.
Citation Count: 0
A numerical study of initial pressure effects on the water/silver nanofluid interaction with SARS-CoV-2 structure; a molecular dynamics method
(Elsevier, 2024) Li, Xiaobo; Salahshour, Soheıl; Sajadi, S. Mohammad; Fan, Guang; Al-Rubaye, Ameer H.; Nasajpour-Esfahani, Navid; Sabetvand, Rozbeh
The stability of the SARS virus can be affected by various environmental factors, including temperature, humidity, and pressure. In the present research, the effect of initial pressure on the stability of the SARS virus in the presence of water/Ag nanofluid (NF) is investigated using molecular dynamics (MD) simulation. The results revealed that initial pressure effectively changes the atomic evolution of the virus-NF system. Numerically, the diffusion coefficient of modeled samples changes from 32.33 nm2/ns to 9.489 nm2/ns by initial pressure varies from 1 bar to 10 bar. This structural evolution caused interatomic distance and force between virus particle changes. Finally, interaction energy is changed by initial pressure variation, and this parameter varies between -0.44695 kcal/mol to -24.65127 kcal/mol in defined initial conditions. From MD outputs, it was concluded physical stability of the SARS virus in the presence of water/silver NF can be manipulated by initial pressure. So, the SARS virus destruction process with water/silver NF affected from the initial pressure ratio, appropriately. Future directions for this research project may involve exploring the influence of additional environmental factors and utilizing the gained knowledge to develop antiviral materials. This study establishes a foundation for further investigations into the interaction between environmental factors, NFs, and viral infections, with the potential to contribute to the development of effective strategies for combating viral infections and designing innovative antiviral solutions.
Citation Count: 3
Obtaining an accurate prediction model for viscosity of a new nano-lubricant containing multi-walled carbon nanotube-titanium dioxide nanoparticles with oil SAE50
(Elsevier Sci Ltd, 2024) Zhang, Yuelei; Salahshour, Soheıl; Sajadi, S. Mohammad; Li, Z.; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Khabaz, Mohamad Khaje
This study aims to investigate the viscosity behavior of multi-walled carbon nanotube (MWCNT) - titanium dioxide (TiO2) (40-60) - SAE50 oil nanofluid using an Artificial Neural Network (ANN) modeling approach. The main objective is to develop a highly accurate predictive model for viscosity by considering three input parameters: temperature, solid volume fraction (SVF), and shear rate (SR). Rheological measurements provide experimental data used to train and validate the ANN model. The ANN model's architecture, activation functions, and training algorithms are carefully chosen. Data are divided to three subsets including train, validation and test. ANN is trained using trainlm algorithm for 50 times to vanish the effect of random nature of ANN weight initialization. The trained ANN model is then utilized to predict the viscosity of the nanofluid under varying conditions. The results demonstrate the efficacy of the proposed ANN model in capturing the complex relationship between viscosity and the input parameters, providing accurate viscosity predictions for the MWCNT-TiO2-oil SAE50 nanofluid. Furthermore, the influence of temperature, SVF, and SR on viscosity is analyzed, offering valuable insights into the flow behavior of the nanofluid. According to the obtained results, the developed ANN model presents a reliable and efficient approach to estimate the viscosity of the MWCNTTiO2-SAE50 oil nanofluid, eliminating the need for costly and extensive experimental measurements within the analyzed range. ANN could model the nanofluid viscosity with R2 = 0.9998 and MSE= 0.000189 that is quite acceptable. Also, the experimental data revealed that for the investigated nanofluid, temperature and shear rate have impressive effect on the viscosity (changing viscosity more than 100% for the analyzed margin), on the other hand, the nanoparticle volume fraction effect is much lower, to be more precise, increasing the nanoparticle percentage will increase the viscosity mean value around 30%.
Citation Count: 1
Offering a channel for cooling three lithium-ion battery packs with water/ Cu nanofluid: An exergoeconomic analysis
(Elsevier, 2024) Zhao, Long; Salahshour, Soheıl; Alizadeh, As 'ad; Shirani, Nima; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Shamsborhan, Mahmoud
This study focused on addressing the heat generation issue in Lithium -Ion battery packs (LIBPs). By simulating three LIBPs arranged in series within a duct, the momentum and energy conservation equations were solved using Computational Fluid Dynamics (CFD) to investigate cooling performance on the LIBPs ' temperature. To enhance cooling, copper oxide nanoparticles were added to pure water to improve the thermal conductivity of the working fluid. Various cases were simulated to examine the effects of Reynolds number at inlet and volume fraction of copper oxide nanoparticles on flow parameters (streamlines, vortices, pressure drop) and heat transfer parameters (temperature distribution, maximum and average temperature of each LIBP) within the duct. Also, this study analyzed exergoeconomics by considering exergies and initial investment. The results demonstrate that increasing the volume fraction from 0 to 4 % at Re = 60 reduced the maximum temperature of LIBP 1, 2, and 3 by 2.19 degrees C, 2.26 degrees C, and 2.64 degrees C, respectively, while it had no remarkable impact on the maximum temperature of LIBPs for bigger Reynolds numbers.
Citation Count: 1
Optimization of thermophysical properties of nanofluids using a hybrid procedure based on machine learning, multi-objective optimization, and multi-criteria decision-making
(Elsevier Science Sa, 2024) Zhang, Tao; Salahshour, Soheıl; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Maleki, Hamid; Baghaei, Sh.
The rheological and thermal behavior of nanofluids in real-world scenarios is significantly affected by their thermophysical properties (TPPs). Therefore, optimizing TPPs can remarkably improve the performance of nanofluids. In this regard, in the present study, a hybrid strategy is proposed that combines machine learning (ML), multi-objective optimization (MOO), and multi-criteria decision-making (MCDM) to select optimal parameters for water-based multi-walled carbon nanotubes (MWCNTs)-oxide hybrid nanofluids. In the first step, four critical TPPs, including density ratio (DR), viscosity ratio (VR), specific heat capacity ratio (SHCR), and thermal conductivity ratio (TCR), are modeled using two efficient ML techniques, the group method of data handling neural network (GMDH-NN) and combinatorial (COMBI) algorithm. In the next step, the superior models are subjected to a four-objective optimization by the well-known non-dominated sorting genetic algorithm II (NSGA-II), which aims to minimize DR/VR and maximize SHCR/TCR. This study considers volume fraction (VF), oxide nanoparticle (NP) type, and system temperature as optimization variables. In the final step, two prominent MCDM techniques, TOPSIS and VIKOR, were used to identify the desirable optimal points from the Pareto fronts generated by the MOO algorithm. ML results reveal the COMBI algorithm's superior reliability in accurately modeling various TPPs. The pattern of Pareto fronts for all oxide-NPs indicated that over one-third of the optimal points have a VF > 1.5 %. On the other hand, the distribution of optimal points across different temperature ranges varied significantly depending on the type of oxide-NPs. For Al2O3-based nanofluid, around 90 % of the optimal points were within 40-50 degrees C. Conversely, for nanofluids containing CeO2 NPs, only approximately 24 % of the optimal points were found within the same temperature range. Considering diverse scenarios for weighting TPPs in the MCDM process implied that combining CeO2/ZnO oxide-NPs with MWCNTs in water-based nanofluids is highly effective across various real-world applications.
Citation Count: 1
Using adaptive neuro-fuzzy inference system for predicting thermal conductivity of silica -MWCNT-alumina/water hybrid nanofluid
(Elsevier, 2023) Zhou, Yuan; Salahshour, Soheıl; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Eftekhari, S. Ali
In this study, the thermal conductivity (knf) of Silicon Oxide-MWCNT-Alumina/Water hybrid nanofluid (HNF) is predicted versus solid volume fraction (SVF) and temperature. For this reason, various combinations of SVF and temperature are considered from SVF= 0.1-0.5% and 20-60 (degrees C) respectively. Then, an adaptive neuro-fuzzy inference system (ANFIS) has been effectively used to model the knf of HNF as one of the effective machine learning techniques. Various shapes of membership functions are considered and the generalized bell shape membership function showed to have acceptable accuracy for knf prediction using an ANFIS-based model. Moreover, the outcomes reveal that the effect of SVF is higher than temperature influence on the knf of HNF. Specifically, when the SVF is increased from 0.1% to 0.5%, there is an approximate 25% increase in knf. Conversely, an increase in temperature leads to a smaller ratio of knf increment. When the temperature rises from 20 degrees to 60 degrees C, knf only increases by less than 10%. The highest error value is found at phi = 0.2% and T = 60 degrees C, amounting to 0.01128 W/mK.
Citation Count: 0
Using molecular dynamics approach to investigate the effect of copper nanoparticles on the thermal behavior of the ammonia/copper coolant by focusing on aggregation time
(Elsevier, 2024) Fan, Zhongmian; Salahshour, Soheıl; Sajadi, S. Mohammad; Salahshour, Soheil; Nasajpour-Esfahani, Navid; Toghraie, D.
Nanofluids, fluids containing nanometer-sized particles, have significant properties which make them useful in devices and systems. They boost thermal conductivity and heat transfer better than base fluid. This research studied the atomic behavior, and thermal behavior of simulated ammonia -copper nanofluid using molecular dynamics (MD) simulation method. The effect of increasing Cu nanoparticles' volume fraction (phi) (1-10 %) on the atomic behavior and thermal behavior of nanofluids was studied. The atomic behavior of simulated structure was studied with velocity and temperature profiles. The maximum values of velocity and temperature were 0.00086 angstrom/ps and 240 K, respectively. To study the thermal behavior of simulated structure, heat flux and the aggregation time (AT) of nanoparticles (NPs) were studied. Numerically, the heat flux (HF) and the aggregation time of Ammonia -Cu nanofluid converged to 1411 W/m2 and 3.96 ns, respectively. The study showed that the maximum velocity and temperature decreased by increasing phi. Moreover, by increasing the phi to 5 %, the heat flux and aggregation time increase to 1553 W/m2 and 4.05 ns. By more increase of NPs up to 10 %, the heat flux and AT of samples decrease. By increasing NPs by 10 % in the base fluid, the aggregation process of NPs occurred in a shorter time. It reduces the thermal efficiency of simulated samples.