Investigating the effect of angular acceleration of the rotating disk having variable thickness and density function on shear stress and tangential displacement

Author(s):  
Mortaza Salehian ◽  
Behrooz Shahriari ◽  
Masood Yousefi
2021 ◽  
Author(s):  
A. S. Begun ◽  
A. A. Burenin ◽  
L. V. Kovtanyuk ◽  
A. N. Prokudin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bai Yu ◽  
Muhammad Ramzan ◽  
Saima Riasat ◽  
Seifedine Kadry ◽  
Yu-Ming Chu ◽  
...  

AbstractThe nanofluids owing to their alluring attributes like enhanced thermal conductivity and better heat transfer characteristics have a vast variety of applications ranging from space technology to nuclear reactors etc. The present study highlights the Ostwald-de-Waele nanofluid flow past a rotating disk of variable thickness in a porous medium with a melting heat transfer phenomenon. The surface catalyzed reaction is added to the homogeneous-heterogeneous reaction that triggers the rate of the chemical reaction. The added feature of the variable thermal conductivity and the viscosity instead of their constant values also boosts the novelty of the undertaken problem. The modeled problem is erected in the form of a system of partial differential equations. Engaging similarity transformation, the set of ordinary differential equations are obtained. The coupled equations are numerically solved by using the bvp4c built-in MATLAB function. The drag coefficient and Nusselt number are plotted for arising parameters. The results revealed that increasing surface catalyzed parameter causes a decline in thermal profile more efficiently. Further, the power-law index is more influential than the variable thickness disk index. The numerical results show that variations in dimensionless thickness coefficient do not make any effect. However, increasing power-law index causing an upsurge in radial, axial, tangential, velocities, and thermal profile.


2021 ◽  
Author(s):  
Shigehiro Hashimoto ◽  
Hiroki Yonezawa

Abstract A cell deforms and migrates on the scaffold under mechanical stimuli in vivo. In this study, a cell with division during shear stress stimulation has been observed in vitro. Before and after division, both migration and deformation of each cell were analyzed. To make a Couette-type shear flow, the medium was sandwiched between parallel disks (the lower stationary culture-disc and the upper rotating disk) with a constant gap. The wall shear stress (1.5 Pa < τ < 2 Pa) on the surface of the lower culture plate was controlled by the rotational speed of the upper disc. Myoblasts (C2C12: mouse myoblast cell line) were used in the test. After cultivation without flow for 24 hours for adhesion of the cells to the lower disk, constant τ was applied to the cells in the incubator for 7 days. The behavior of each cell during shear was tracked by time-lapse images observed by an inverted phase contrast microscope placed in the incubator. Experimental results show that each cell tends to divide after higher activities: deformation and migration. The tendency is remarkable at the shear stress of 1.5 Pa.


1952 ◽  
Vol 19 (3) ◽  
pp. 263-266
Author(s):  
Ti-Chiang Lee

Abstract This paper presents an analytic solution of the stresses in a rotating disk of variable thickness. By introducing two parameters, the profile of the disk is assumed to vary exponentially with any power of the radial distance from the center of the disk. In some respects this solution may be considered as a generalization of Malkin’s solution, but it differs essentially from the latter in the method of solution. Here, the stresses are solved through a stress function instead of being solved directly. The required stress function is expressed in terms of confluent hypergeometric functions. Numerical examples are also shown for illustration.


2007 ◽  
Vol 292 (6) ◽  
pp. H3128-H3135 ◽  
Author(s):  
Jeffrey S. Garanich ◽  
Rishi A. Mathura ◽  
Zhong-Dong Shi ◽  
John M. Tarbell

The involvement of vascular fibroblasts (FBs) and smooth muscle (SM)-like cells in physiological and pathological processes in large vessels (intimal hyperplasia) and microvessels (capillary arterialization), and the realization that these cells are exposed to interstitial flow shear stress (SS), motivate this study of SS on FB migratory activity. Rat adventitial FBs were grown to either 30–50% confluence (subconfluent FBs; SFBs) or full confluence (confluent FBs; CFBs) in culture. Immunofluorescence and Western blotting assays were conducted to evaluate the expression of two phenotype markers: SM α-actin and SM myosin heavy chain (MHC). Both assays indicated a significant increase in SM α-actin expression in CFBs compared with SFBs, suggesting a phenotype difference between the two cell populations. SFBs and CFBs both expressed minimal SM MHC. Both cell populations were seeded on Matrigel-coated cell culture inserts and exposed to 4 h of either 1 or 20 dyn/cm2 SS via a rotating disk apparatus in the presence of the chemoattractant platelet-derived growth factor-BB to quantify the effect of SS on SFB and CFB migration. Four hours of 20 dyn/cm2 SS significantly enhanced SFB migration while it suppressed CFB migratory activity. Four hours of 1 dyn/cm2 SS did not significantly alter either SFB or CFB migration levels. Because of the distinct migratory responses of SFBs and CFBs in response to SS, phenotype modulation appears to be one way to regulate their involvement in both physiological and pathological remodeling processes.


2017 ◽  
Vol 7 ◽  
pp. 156-165 ◽  
Author(s):  
Tasawar Hayat ◽  
Sumaira Qayyum ◽  
Maria Imtiaz ◽  
Ahmed Alsaedi

Sign in / Sign up

Export Citation Format

Share Document