Boiling of Argon flow in a microchannel by considering the spherical geometry for roughness barriers

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Journal of Molecular Liquids 321 (2021) 114462

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Journal of Molecular Liquids journal homepage: www.elsevier.com/locate/molliq

Boiling of Argon flow in a microchannel by considering the spherical geometry for roughness barriers using molecular dynamics simulation Amirhosein Mosavi a,b, Majid Zarringhalam c, Davood Toghraie d, Amin Rahmani e, Aliakbar Karimipour f,⁎ a

Environmental Quality, Atmospheric Science and Climate Change Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam Department of Mechanical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran d Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Iran e Department Mechanical Engineering, Isfahan University of Technology, Isfahan 84156, Iran f Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam b c

a r t i c l e

i n f o

Article history: Received 11 June 2020 Received in revised form 31 August 2020 Accepted 27 September 2020 Available online 12 October 2020 Keywords: Microchannel Boiling Spherical roughness Molecular dynamic simulation

a b s t r a c t In this research, the method of molecular dynamic (MD) is used to consider the influences of the spherical roughness barrier on the boiling flow regime of Argon particles, flowing into microchannel with a square cross-section. To prepare boiling conditions, different constant temperatures from 84 K to 133 K are applied on the walls of microchannels. Results show that roughness elements help boiling thermal forces to the distribution of fluid atoms in central layers of a microchannel, especially at high time steps between 750,000 and 1,000,000. This phenomenon is noticeable under applied high wall temperatures of 114 K and 133 K. Also, a summation of velocity values indicated that increasing boundary wall temperatures of rough microchannels results in a small reduction of the velocity of fluid flow, whereas; it is almost unchanged in the smooth microchannel. The statistical approach shows that the presence of spherical roughness does not have a destructive influence on the boiling flow properties of Argon into the microchannel. Also, they are useful to enhance effective surfaces of heat transfer, which empower the boiling process. Therefore, investing in polishing microchannel surfaces and removing the spherical shape of roughness components can even be a serious mistake for some of the practical applications. © 2020 Elsevier B.V. All rights reserved.

1. Introduction Nowadays, the application of Argon fluid is increasing in some medical surgeries due to its boiling capability in very low temperatures which brings rapid coagulation in tissues and blood [1,2]. Employing Argon fluid in this method reduces damage area in tears and bleeding of body tissues. On the other side, it increases improvement speed due to decreasing perforation depth in the patient's body and reduces the risk of infection. Also, this method is even employed to destroy cancers and tumors cells in micro-scale by medical microprobes which are not easily analyzed especially by in small scale of microchannels and membranes[3–8]. For very small scales of systems, the continuum model is not reliable [9]. The alternative is to employ the Molecular Dynamic Simulation (MDS) method [10]. This method is one of the best to consider the physical movements of particles. In the MDS method, atoms and molecules are allowed to interact for a fixed period to give a dynamic visual description of the system. Before emerging possibility to simulate the ⁎ Corresponding author. E-mail addresses: amirhosein.mosavi@tdtu.edu.vn (A. Mosavi), aliakbarkarimipour@duytan.edu.vn (A. Karimipour).

https://doi.org/10.1016/j.molliq.2020.114462 0167-7322/© 2020 Elsevier B.V. All rights reserved.

molecular dynamics with computers, it was the idea to use experimental physical models such as macroscopic spheres. The idea was to sort them out to repeat the fluid properties, but fortunately, today computers keep track of the lines [11,12]. Therefore, it is presently only applicable to small systems. Molecular dynamics simulation was initially carried out in 1957 for a system composed of hard spheres by Alder and Wainwright [13]. In their system, particles were moving with a completely constant speed, and the collision between particles was quite elastic. Therefore, it was possible to solve a dynamic problem without any approximation. Next, in 1964, Rahman [14] employed this method for Lennard-Jones particles. Then, this potential function was commonly used by other researchers. Afterward, Craig et al. [15], Zhu and Granick [16], and Tretheway and Meinhart [17], experimentally showed that flow slippage in a nanoscale depends strongly to the interaction between wall-fluid and surface roughness effects. Generally, most of the papers by molecular dynamic simulation method present investigation of nanoflows [18–26]. The majority of presented channels in the mentioned references are in nanoscale [18–22], and others are related to surface phenomenon [23–26]. Moreover, previous papers contain a simulation domain with a small number of particles. Therefore, presenting a molecular dynamics simulation study on the fluid flow inside microchannels with a large number of Argon atoms under phase


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