Browsing by Author "Al-Rubaye, Ameer H."

Now showing 1 - 5 of 5

Citation Count: 0
Calculating minimum droplet diameter in dripping, spindle, and cone-jet modes based on experimental data in the electrospray process
(Elsevier Science inc, 2024) Wang, Shi; Salahshour, Soheıl; Alizadeh, As'ad; Basem, Ali; Jasim, Dheyaa J.; Al-Rubaye, Ameer H.; Toghraie, Davood
The paper is an experimental investigation of the effect of process parameters like applied voltage, volume flow rate and distance between two electrodes through dimensionless numbers in the electrospray process, droplet diameter in particular. In addition, this study attempts to present new estimated formulas based on experimental data to ease primary evaluations of droplet diameter before any performing electrospray applications in order to reduce time and cost spending. For this purpose, a high-speed camera was used to have clear evidence of the influence of the parameters on the diameter of liquid droplets generated from acetic acid and their electrohydrodynamic (EHD) modes. In this study, the time evolution of EHD modes detected during experiments and the reasons for EHD mode geometric shapes were physically stated. The results show that decreasing the distance between two electrodes producing an electric field causes a reduction in the voltage to meet desired droplet diameter (needed minimum droplet diameter) and a switch of EHD modes occurs in lower voltages. This paper also demonstrates that the percentage of decreasing droplet diameter during the electrospray process has the extremum which can change based on changing effective parameters. Furthermore, a quick estimation for calculating minimum droplet diameter in dripping, spindle, and cone-jet modes based on experimental data is presented because it was observed the decreasing percentage of droplet diameters in each EHD mode is approximately constant unexpectedly whereas all effective parameters of the electrospray process in this research tested. Finally, another equation was also driven to calculate the decreasing percentage of droplet diameter based on dimensionless numbers, Weber and Electric Capillary numbers, using experimental data to acquire appropriate means for the primary forecast of the trend of droplet diameter production being useful for various of electrospray processes such as drug delivery, powder production, encapsulation, thin films, and electrospinning.
Citation Count: 0
The effect of initial temperature and oxygen ratio on air-methane catalytic combustion in a helical microchannel using molecular dynamics approach
(Elsevier, 2024) An, Qing; Salahshour, Soheıl; Alizadeh, As'ad; Al-Rubaye, Ameer H.; Jasim, Dheyaa J.; Tang, Miao; Sabetvand, Rozbeh
In industrial environments where combustion (Com.) is widely carried out, such as steam power plants, gas turbines, etc., the most common way to express the amount of oxygen consumption is its excess percentage in addition to the stoichiometric ratio, and the nearness of a catalyst causes combustion to happen at a high ratio. There are different influential factors in catalytic combustion, such as initial temperature (IT). The current study uses the molecular dynamics (MD) method to examine how the IT and oxygen ratio affect air -methane catalytic combustion in a heli- cal microchannel. The LAMMPS package was used to conduct this investigation. This study exam- ines how simulated structures function during burning in excess oxygen (EO) and oxygen defi- ciency (OD). Furthermore, palladium was used as a catalyst with an atomic ratio of 4 %. The find- ings show that raising the IT may enhance its atomic behavior (AB) and thermal performance (TP). The maximum velocity (MV) and maximum temperature (MT) increased from 0.26 angstrom/ps and 1617 K to 0.45 angstrom/ps and 1891 K in EO as IT increased from 300 to 700 K. By accelerating the particle velocity, it is anticipated that the catalytic combustion process would proceed more quickly. As a result, after increasing the IT to 700 K, the heat flux (HF), thermal conductivity (TC), and combustion efficiency (CE) increase to 2101 W/m2, 1.23 W/m. K, and 93 %, respec- tively. On the other hand, the results show that increasing IT affects combustion performance in the presence of OD. In the presence of OD, the MV and CE converge to 0.38 angstrom/ps and 94 % at 700 K. Therefore. It can be concluded that the atomic ratio of oxygen and the IT can significantly affect combustion process.
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 pH on the swelling process, mechanical and thermal attributes of polyacrylamide hydrogel structure: A molecular dynamics study
(Elsevier, 2024) Liu, Zhiming; Salahshour, Soheıl; Mostafa, Loghman; Jasim, Dheyaa J.; Al-Rubaye, Ameer H.; Salahshour, Soheil; Esmaeili, Shadi
Stimuli-responsive hydrogels are a class of hydrogels that undergo reversible changes in their physical or chemical properties in response to specific external stimuli. The pH is a critical environmental stimulus for stimuli-responsive hydrogels. When the pH of the surrounding environment changes, it can lead to significant alterations in the properties of the hydrogel, such as swelling behavior, mechanical strength, etc. So, understanding how pH affects the swelling behavior and mechanical properties of these hydrogels is crucial to optimize their performance in biomedical applications. Therefore, in the present study, the effect of pH on the swelling process, mechanical and thermal attributes of polyacrylamide hydrogel structure were studied using molecular dynamics simulation and LAMMPS software. The results reveal that as the pH increased from 2 to 11, the structural volume increased from 342,583 to & Aring;3. The increase in the volume of the structure was in terms of the increase in atomic fluctuations by increasing the pH, and consequently, it led to more swelling. The mechanical properties show that the ultimate strength and Young's modulus of the sample increase from 0.0298 to 0.0007 to 0.0359 and 0.0012 MPa, respectively. The reason for the increase in these parameters was that by increasing the pH, the attraction force among different components of the PAM hydrogel structure increased. This issue led to an increase in the stability of the nanostructure. Finally, the thermal properties showed that thermal conductivity increased from 0.51 to 0.62 W/m K by increasing pH to 11. The findings may lead to the development of pH-responsive hydrogels with enhanced properties, offering more effective and tailored solutions for biomedical 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.