scholarly journals Two-phase modeling of three-dimensional MHD porous flow of Upper-Convected Maxwell (UCM) nanofluids due to a bidirectional stretching surface: Homotopy perturbation method and highly nonlinear system of coupled equations

2018 ◽  
Vol 21 (4) ◽  
pp. 714-726 ◽  
Author(s):  
Amin Jafarimoghaddam
2018 ◽  
Vol 17 (06) ◽  
pp. 1850004
Author(s):  
Sapna Ratan Shah ◽  
Rohit Kumar

This paper presents the effect of heat and mass transfer on the blood flow through a tapered stenosed artery assuming blood as a Jeffrey fluid model. The equations governing the blood flow are modeled in cylindrical coordinates. Analytical solutions are constructed for the velocity, temperature, concentration and flux by solving flow governing nonlinear coupled equations using Homotopy Perturbation Method. The important characteristics of blood flow such as concentration and temperature are found by using Homotopy Perturbation Method and these solutions are used to find exact solution for velocity profile. Variation in velocity, temperature, concentration and flux profiles for different values of thermophoresis and Brownian motion parameter are discussed. Homotopy Perturbation Method technique is used to calculate these expressions and Matlab programming is used to find computational results. And then computational results are presented graphically. The significance of the present model over the existing models has been pointed out by comparing the result with other theories both analytically and numerically. Here, in this paper, we have discussed some important phenomena raised in biotechnology and medicine at the nanoscale. So, this paper about nanoparticles behavior could be useful in the development of new diagnosis tools for many diseases in medical field, biotechnology as well as in medicine at the nanoscale.


2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Jianjian Xin ◽  
Fulong Shi ◽  
Qiu Jin ◽  
Lin Ma

Abstract A three-dimensional (3D) gradient-augmented level set (GALS) two-phase flow model with a pretreated reinitialization procedure is developed to simulate violent sloshing in a cuboid tank. Based on a two-dimensional (2D) GALS method, 3D Hermite, and 3D Lagrange polynomial schemes are derived to interpolate the level set function and the velocity field at arbitrary positions over a cell, respectively. A reinitialization procedure is performed on a 3D narrow band to treat the strongly distorted interface and improve computational efficiency. In addition, an identification-correction technique is proposed and incorporated into the reinitialization procedure to treat the tiny droplet which can distort the free surface shape, even lead to computation failure. To validate the accuracy of the present GALS method and the effectiveness of the proposed identification-correction technique, a 3D velocity advection case is first simulated. The present method is validated to have better mass conservation property than the classical level set and original GALS methods. Also, distorted and thin interfaces are well captured on all grid resolutions by the present GALS method. Then, sloshing under coupled surge and sway excitation, sloshing under rotational excitation are simulated. Good agreements are obtained when the present wave and pressure results are compared with the experimental and numerical results. In addition, the highly nonlinear free surface is observed, and the relationship between the excitation frequency and the impulsive pressure is investigated.


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