Browsing by Author "Abduvalieva, Dilsora"

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Citation Count: 0
Evaluation of the growth process of soot mass due to changes in hydrogen atomic percentage and external heat flux using molecular dynamics simulation
(Elsevier, 2024) Sun, Shouqiang; Ali, Ali B. M.; Abdul-Redha, Hadeel Kareem; Alardhi, Saja Mohsen; Ahmad, Nafis; Abduvalieva, Dilsora; Sabetvand, Rozbeh
Studying how polycyclic aromatic hydrocarbons transform into soot particles provides insights into factors affecting their formation, composition, and size distribution. Understanding the growth mechanisms of soot from PAHs is crucial for combustion processes and energy efficiency, addressing environmental, health, and energy challenges linked to soot emissions and air pollution. This research aimed to deepen our understanding of these mechanisms by investigating them through molecular dynamics simulations. It used naphthalene as a representative polycyclic aromatic hydrocarbon. The study explored the effect of parameters like hydrogen atomic percentage and heat flux on properties, such as interaction energy, center of mass size, and soot mass size. Results show that increasing hydrogen atomic percentage from 5 % to 25 % increases the interaction energy from -0.15 to -0.12 kcal/mol. At the same time, it reduces the center of mass size from 92.31 to 88.27 & Aring; and the soot mass size from 30.13 to 28.30 & Aring;. Moreover, raising external heat flux from 0.01 to 0.05 W/m2 increases the interaction energy from-0.1 to-0.08 kcal/mol, but increases the center of mass size from 88.49 to 90.18 & Aring; and soot mass size from 28.33 to 30.30 & Aring; after 10 ns.
Citation Count: 0
Numerical study of changes in the mechanical and thermal property of porous silicon sample with increasing initial temperature: A molecular dynamics approach
(Pergamon-elsevier Science Ltd, 2024) Liu, Shupeng; Ali, Ali B. M.; Hussein, Muntadher Abed; Kumar, Anjan; Abduvalieva, Dilsora; Abdul-Redha, Hadeel Kareem; Emami, Nafiseh
The mechanical and thermal properties of porous silicon samples were examined in this investigation in relation to their initial temperature (Temp). The molecular dynamics (MD) numerical simulation method was employed to analyze the results, and LAMMPS software was used to model the porous sample. The simulations conducted in the present study predicted the physical equilibrium of porous silicon samples that were modeled. The research results indicate that the ultimate strength and Young's modulus of porous structures decreased from 26.559 and 52.484 GPa to 25.830 and 52.304 GPa as the Temp increased from 300 to 500 K. The results indicate that the toughness decreased from 10.788 eV/& Aring;3 to 10.195 eV/& Aring;3 as the initial Temp increased to 500 K. Additionally, MSD and diffusion coefficient of porous silicon sample increased from 3.88 nm2 and 27.86 nm2/ns to 8.67 nm2 and 75.56 nm2/ns when the Temp increased from 300 K to 500 K. As the Temp increases to 500 K, the COM increases from 0.236 to 0.41 & Aring;. The total energy of system decreases to -29,259.648 eV when the initial Temp of the porous silicon sample increases to 500 K. Changes in the atomic-scale dynamics and the structural properties of porous silicon network were responsible for this tendency. This study's novelty lies in its focus on the unknown relationship between Temp and porous silicon performance. The results of this study indicate that the Temp had a significant effect on the mechanical and thermal properties of porous silicon samples. These findings are necessary to advance the practical use of porous silicon in various technological fields, especially in Tempsensitive applications, where understanding its behavior under different thermal conditions is very important.