Araştırma Çıktıları | WoS | Scopus | TR-Dizin | PubMed
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Publication Metadata only 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; Jasim, Dheyaa J.; Sajadi, S. Mohammad; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Esmaeili, Shadi; Sabetvand, Rozbeh; Elhag, Ahmed Faisal Ahmed; University Ha'il; Universite de Sfax; Ecole Nationale dIngenieurs de Sfax (ENIS); Al-Amarah University College; Cihan University-Erbil; University System of Georgia; Georgia Institute of Technology; Okan University; Lebanese American University; Bahcesehir University; Semnan University; Amirkabir University of Technology; Qassim UniversityAtomic 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.Publication Metadata only 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; Jasim, Dheyaa J.; Alizadeh, Asad; Keivani, Babak; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Shamsborhan, Mahmoud; Sabetvand, Rozbeh; North China University of Water Resources & Electric Power; Shanghai Jiao Tong University; Al-Amarah University College; Cihan University-Erbil; Kirsehir Ahi Evran University; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; University of Zakho; Amirkabir University of Technology; Xi'an University of Science & TechnologyNanofluids (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.Publication Metadata only Numerical examination of exergy performance of a hybrid solar system equipped with a sheet-and-sinusoidal tube collector: Developing a predictive function using artificial neural network(ELSEVIER, 2024) Sun, Chuan; Fares, Mohammad N.; Sajadi, S. Mohammad; Li, Z.; Jasim, Dheyaa J.; Hammoodi, Karrar A.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Alizadeh, As'ad; Huanggang Normal University; University of Basrah; Cihan University-Erbil; Donghai Laboratory; Opole University of Technology; Al-Amarah University College; University of Warith Alanbiyaa; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Urmia UniversityIntegrating cooling systems with photovoltaic-thermal (PVT) collectors has the potential to mitigate the exergy consumption in the building sector due to their capability for simultaneous power and thermal energy generation. The simultaneous utilization of nanofluid and geometry modification resulted in a synergetic enhancement in the performance of PVTs and thereby reducing their sizes and costs. In addition, there is still a lack of high accurate predictive model for the estimation of the performance of PVTs at a given Re number and nanofluid concentration ratio to be used in engineering design for the further product commercialization. To this end, the current numerical study investigates the exergy electricity, thermal, and overall exergies of a building-integrated photovoltaic thermal (BIPVT) solar collector with Al2O3/water coolant. The increase in nanoparticle concentration (omega) from 0 % to 1 % increased the useful thermal exergy and overall exergy efficiency (Exu,t/ Yov) by 0.3999 %/0.0497 %, 1.3959 %/0.2598 %, and 0.7489 %/0.1771 % at Re numbers of 500, 1000, and 1500, respectively, while Exu,t/ Yov exhibited a reducing trend at Re = 2000, 0.3928 %/0.1056 % decrease. In addition, the increase in omega from 0 % to 1 % caused the useful electricity and electrical exergy (Exu,e/ Ye) to be diminished by 0.0060 %/0.0025 % at Res 500 and 1000, and to be escalated by 0.0113 %/0.0055 % at Res of 1500 and 2000. Meanwhile, the Re augmentation, from 500 to 2000, improved the Exu,t, Exe, Ye, and Yov by 60 %, 1.26 %, 1.26 %, and 17.50 %, respectively, at different omega s. In addition, two functions were developed and proposed by applying a group method of data handling-type neural network (GMDH-ANN) to forecast the value of Υov based on two input values (Re and omega). The results showed high accuracy of the proposed model with MSE, EMSE, and R2 of 0.0138, 0.1143, and 0.99785, respectively.Publication Metadata only 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; Jasim, Dheyaa J.; Alizadeh, As'ad; Eftekhari, S. Ali; Nasajpour-Esfahani, Navid; Zekri, Hussein; Salahshour, Soheil; Toghraie, Davood; Al-Amarah University College; Cihan University-Erbil; Islamic Azad University; University System of Georgia; Georgia Institute of Technology; University of Zakho; Bahcesehir University; Lebanese American University; Okan UniversityOne 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.Publication Metadata only A numerical study of carbon doping effect on paraffin-reinforced silica aerogel mechanical properties: A molecular dynamics approach(ELSEVIER, 2023) Zhang, Wei; Jasim, Dheyaa J.; Alizadeh, As'ad; Nasajpour-Esfahani, Navid; Hekmatifar, Maboud; Sabetvand, Roozbeh; Salahshour, Soheil; Toghraie, D.; Xi'an Jiaotong University City College; Al-Amarah University College; Cihan University-Erbil; University System of Georgia; Georgia Institute of Technology; Islamic Azad University; Amirkabir University of Technology; Okan University; Bahcesehir University; Lebanese American UniversityAerogels 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.Publication Metadata only 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; Jasim, Dheyaa J.; Sajadi, S. Mohammad; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Zarringhalm, Majid; Rahmani, Amin; Al-Amarah University College; Cihan University-Erbil; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Islamic Azad University; University of ExeterBackground: 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.Publication Metadata only 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; Rasheed, Rassol H.; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Salahshour, Soheil; Nasajpour-Esfahani, Navid; Sabetvand, Rozbeh; University of Warith Alanbiyaa; Cihan University-Erbil; Al-Amarah University College; Okan University; Bahcesehir University; Lebanese American University; University System of Georgia; Georgia Institute of Technology; Amirkabir University of TechnologyToday, 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.Publication Metadata only 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; Hammoodi, Karrar A.; Sajadi, S. Mohammad; Li, Z.; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Eftekhari, S. A.; Khabaz, Mohamad Khaje; Wuchang University of Technology; University of Warith Alanbiyaa; Cihan University-Erbil; Donghai Laboratory; Opole University of Technology; Al-Amarah University College; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Islamic Azad UniversityThis 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%.Publication Metadata only 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; Jasim, Dheyaa J.; Alizadeh, As'ad; Al-Rubaye, Ameer H.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Esmaeili, Shadi; Hekmatifar, M.; Yangzhou University; Al-Amarah University College; Cihan University-Erbil; Al-Kitab University; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Semnan University; Islamic Azad University; Yangzhou UniversityOne 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.Publication Metadata only 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; Basem, Ali; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Esmaeili, Shadi; Baghaei, Sh.; Nanyang Normal College; University of Warith Alanbiyaa; Cihan University-Erbil; Al-Amarah University College; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Semnan University; Islamic Azad UniversityAmidst 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.