Faculty Publications

Now showing 1 - 4 of 4

Numerical simulation of oscillating lid driven square cavity
(Elsevier B.V., 2018) Indukuri, J.V.; Maniyeri, R.
This paper aim to develop a two-dimensional computational model to study the fluid dynamic behaviour in a square cavity driven by an oscillating lid using staggered grid based finite volume method. Firstly the developed computational model is validated with that of other researcher's results for the case of finite wall motion. Later the numerical simulations are performed for the case of top wall oscillations for various combinations of Reynolds number and frequencies. From these simulations an optimum frequency is chosen and then with the optimum frequency the simulations are carried out to explore the vortex behaviour for the cases of parallel wall oscillations (both top and bottom walls moving in the same direction) and anti-parallel wall oscillations (both top and bottom walls moving in the opposite direction). From these simulations it may be concluded that Re = 1000 is medium range of operation for better mixing inside the cavity for the cases of parallel and anti-parallel wall oscillations. © 2017 Faculty of Engineering, Alexandria University
Numerical study of forced convection heat transfer in an oscillating lid driven cavity with heated top wall
(International Information and Engineering Technology Association info@iieta.org, 2018) Indukuri, J.V.; Maniyeri, R.
The present work is aimed to study the fluid flow and heat transfer behaviour in an oscillating lid-driven cavity using finite volume method by developing a two-dimensional computational model. Firstly, the developed computational model is validated by comparing our numerical results with that of the other researcher's results for the case of wall moving with finite motion. Next, the simulations are conducted for oscillating cavity problem with top wall oscillation for Reynolds number (Re =5 00) and frequency (?=2?/6). Later, the simulations are carried out for cases of oscillating parallel wall (upper and lower walls oscillating with sync) and oscillating anti-parallel wall (upper and lower walls oscillating with reverse sync) with the same optimum frequency and fixed Reynolds number (Re = 500). Secondly, the same optimum frequency is used to study the heat transfer characteristics in an oscillating lid-driven square cavity with heated top wall and lower cold wall for various Reynolds numbers (Re = 100-1000) and Prandtl numbers (Pr = 0.2 to 1.0). From this study, it is found that for high Prandtl number case (Pr = 1.0) the flow of high temperature isotherms inside the cavity is more when compared with low Prandtl number cases due to increase in molecular diffusion of momentum. © 2018 International Information and Engineering Technology Association.
Finite difference method based analysis of bio-heat transfer in human breast cyst
(Elsevier Ltd, 2019) Patil, H.M.; Maniyeri, R.
Bio-heat transfer is a branch of bio-medical engineering which has its foundation linked to engineering disciplines of heat transfer. The thermal properties and behaviour of various malfunctioning tissues in human body varies as compared with normal tissues. Among various cancer tissues one which is commonly diagnosed in women is breast cyst (cancer causing fluid). The aim of present work is to develop one, two and three-dimensional computational models to study bio-heat transfer problems using finite difference method. First of all, a numerical model based on finite difference method is developed to solve Pennes's bio-heat transfer equation in one-dimension to get temperature profiles normal to skin surface and validated with existing analytical solutions. Secondly, the numerical model is extended to study the thermal behaviour of human breast section embedded with cyst using two-dimensional cylindrical coordinate systems and validated with previous researcher's results. The effect of size, location and presence of multiple cysts on surface temperature is studied. Lastly, the work is extended for the case of three-dimensional breast section with cyst located at the centre. The numerical results obtained using one, two and three-dimensional computational models will be highly helpful in the early detection of breast cancer tissues and also the location of it inside the body. © 2019
Numerical analysis of the buckling and recuperation dynamics of flexible filament using an immersed boundary framework
(Elsevier B.V., 2019) Kanchan, M.; Maniyeri, R.
The dynamics of flexible filaments in viscous shear flow is of interest to biologists and engineers in a wide variety of applications involving folding and unfolding sequence of long-chain biomolecules like DNA, non-motile sperm and microalgae. It is also helpful in understanding the deformation of natural and synthetic fibers which can be applied in areas such as biotechnology. In the present work, deformation and migration behavior of non-motile unicellular phytoplankton diatoms subjected to viscous shear flow are considered. These unicellular diatoms develop into colonies which are made up of linked chains. The complex fluid-structure interaction is solved by developing a two-dimensional numerical model with an immersed boundary framework. The simulation consists of suspending an elastic filament mimicking a diatom chain in a shear flow at low Reynolds number. The governing continuity and Navier–Stokes equations are solved on a Cartesian grid arranged in a staggered manner. A forcing term is added to the momentum equation that incorporates the presence of flexible filament in the fluid domain. The discretization of the governing equation is based on a finite volume method, and a SIMPLE algorithm is used to compute pressure and velocity. A computer code is developed to perform numerical simulations, and the model is first verified with the deformation study of a tethered flexible filament in uniform fluid flow. Next, the shape deformations for flexible filament placed freely in shear flow are compared with the studies of previous researchers. Further, the present results are validated with Jeffery's equation for particles immersed in shear flow along with classification plot for filament orbit regimes. All of these comparisons provide a reasonable validity for the developed model. The effect of bending rigidity and shear rate on the deformation and migration characteristics is ascertained with the help of parametric studies. A non-dimensional parameter called Viscous Flow Forcing value (VFF) is calculated to quantify the parametric results. An optimum Viscous Flow Forcing value is determined which indicates the transition of filaments exhibiting either a recuperative (regaining original shape past deformation) or non-recuperative (permanently deformed) behavior. The developed model is successful in capturing fluid motion, diatom buckling, shape recurrences and recuperation dynamics of diatom chains subjected to shear flow. Further, the developed computational model can successfully illustrate filament-fluid interaction for a wide variety of similar problems. © 2019 Elsevier Inc.

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