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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 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.