Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
41
5
2014
Dynamics of Partially Filled Rectangular Rigid Tank with Surface Piercing Elements
379-408
Arun
Kumar
Department of Aerospace Engineering, IIT Kharagpur Kharagpur-721302, West Bengal, India
K. P.
Sinhamahapatra
Aerospace Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur-721302, West Bengal, India
Slosh dynamics of partially filled liquid tanks are greatly influenced by the presence of structural components within the liquid. The effectiveness of these structural elements depends on various factors such as position, thickness and flexibility. These elements add considerable weight penalty and modify the flow characteristics in the fluid domain which are cause of concern. Baffles are one type of internal components that are often used to suppress sloshing motion of the liquid. Efforts have been made to select the baffle configuration which is most effective and affects the other parameters least. Surface piercing baffles are considered as one of the most effective tools that change the dynamics of partially filled tank with least weight penalty and cost. A surface piercing baffle can also be designed as retrofitting element for those fluid containers which are not originally designed on dynamic consideration. So far numerous theoretical and experimental studies are carried out to investigate the effects of surface piercing baffles in containers of various shapes but numerical studies are scarce. This study aims to understand the effects of surface piercing baffle on slosh dynamics of rigid rectangular tanks numerically using pressure based finite element method. The study also includes combination of bottom mounted baffle and surface piercing baffle.
On the Characterization of Nonoscillatory Motions in Triply Diffusive Convection
409-416
Jyoti
Prakash
Department of Mathematics and Statistics, Himachal Pradesh University, Summer Hill,
Shimla-171005, India
Kanu
Vaid
Department of Mathematics and Statistics, Himachal Pradesh University Summer Hill, Shimla-171005, India
Renu
Bala
Department of Mathematics and Statistics, Himachal Pradesh University Summer Hill, Shimla-171005, India
Conditions for characterizing nonoscillatory motions, which may be neutral or unstable for triply diffusive configurations, is established. The result is uniformly valid for quite general nature of the bounding surfaces.
Laminar Blood Flow through a Model of Arterial Stenosis with Oscillating Wall
417-429
Mir Golam
Rabby
School of Engineering & Applied Science, Dept. of Electrical & Computer Engineering, North South University Dhaka-1229, Bangladesh
Rumia
Sultana
School of Engineering & Applied Science, Dept. of Electrical & Computer Engineering, North South University Dhaka-1229, Bangladesh
Sumaia Parveen
Shupti
School of Engineering & Applied Science, Dept. of Electrical & Computer Engineering, North South University Dhaka-1229, Bangladesh
Md. Mamun
Molla
School of Engineering & Applied Science, Dept. of Electrical & Computer Engineering, North South University Dhaka-1229, Bangladesh
In this research, a numerical investigation of the physics of laminar blood flow through a two-dimensional (2D) pipe with an idealized stenosis with oscillating wall has been studied using the finite volume method. The governing Navier − Stokes equations are modified using the time dependent Cartesian curvilinear coordinates to handle the complex geometry, such as, arterial stenosis. The arterial wall is considered as moving sinusoidally in a radial direction. The computations for this case were carried out for a range of Reynolds number and amplitude of the wall oscillation. The flow is characterized by the Reynolds number, ranging from 100 to 300. The numerical results are presented in terms of the velocity, pressure distribution, wall shear stress as well as the vorticity, streamlines and vector plot indicating the recirculation zones at the post stenotic region. Due to the higher Reynolds number pressure drop is higher after the throat location of stenosis and wall shear stress is maximal at the center of the stenosis.
Effects of Efflux Velocity and Buoyancy on Fuel Jets
430-439
Mohammed A.
Azim
Department of Mechanical Engineering Bangladesh University of Engineering and Technology Dhaka, Bangladesh
This paper investigates the effects of efflux velocity and buoyancy on the flow dynamics of round jets with coflowing hot ambient. Such jets are relevant to the mixing of fuel and air that occur in various combustion devices. The governing equations for the jet flow are solved using the Standard k-ε model, Fully Implicit Numerical Scheme (FINS) and Tridiagonal Matrix Algorithm (TDMA). Calculations are made to discern the effects of efflux velocity and buoyancy due to flow configuration on the mean and turbulent properties of the jets. Obtained results show that change in efflux velocity affects the jet flow largely but change in jet configuration affects the flow significantly at low efflux velocity only. Nonetheless mean vorticity remains unaffected against the change in jet configuration both at high and low efflux velocity.
A Numerical Study on the Control of Self-Excited Shock Induced Oscillation in Transonic Flow around a Supercritical Airfoil
440-459
A.B.M. Toufique
Hasan
Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh
Md. Mahbub
Alam
Biman Bangladesh Airlines Limited Dhaka, Bangladesh
Self-excited shock induced oscillation (SIO) around an airfoil is observed in transonic flows at certain conditions of free stream Mach number and angle of attack. At these conditions, the interaction of unsteady shock wave with airfoil boundary layer becomes complex and causes several detrimental effects such as the fluctuating lift and drag coefficients, aeroacoustic noise and vibration, high cycle fatigue failure (HCF), buffeting and so on. In the present study, Reynolds Averaged Navier-Stokes equations have been used to predict the aerodynamics behaviour over a NASA SC(2) 0714 supercritical airfoil in transonic flow conditions. To suppress the unsteady aerodynamic behaviour, a shock control bump is introduced at the mean shock position. Computations have been performed at free stream Mach number of 0.77 while the angle of attack was varied from 2° to 7°. The results obtained from the numerical computation have been validated with the experimental results. Mach contour, lift and drag coefficient, and pressure history over the airfoil surface have been analyzed for the cases of baseline airfoil and airfoil with bump. It is found that, the bump can control the unsteady SIO in the flow field.
Numerical Investigation of Hydro-Magnetic Flow of Air in a Lid Driven Cavity for an Optimum Magnetic Situation
460-470
Amir Javad
Ahrar
Department of Mechanical Engineering, Faculty of Sadooghi, Yazd Branch, Technical and Vocational University (TVU), Yazd, Iran
Mohammad Hassan
Djavareshkian
Ferdowsi University of Mashhad, Iran
In the present paper, Magneto Hydro Dynamics of air flow in a lid driven cavity is assessed numerically. In this process, the finite volume technique and pressure- based algorithm are used for discretisation. The main scope of this research is to find a suitable magnetic field situation to improve the heat transfer rate. Thus several cases with different Ha numbers and magnetic field angles are investigated in order to find the maximum Nusselt number for the heated wall. Generally, it is considered that with the increase of Ha, the Nu number is reduced. Here it will be shown that although this idea is valid for most cases of Ha numbers and magnetic field angles but there are a few exceptions that refute this fact.