![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
ABSTRACT
A two-dimensional finite volume computation is performed to analyze the transient magnetoconvective transport in a ventilated cavity containing two inner heated circular cylinders with identical shape. An electrically conducting fluid (Prandtl number 0.01) enters the cavity through an opening at the middle of the left wall and is taken away by a similar opening at the middle of the right wall. A uniform magnetic field is applied along the horizontal direction normal to the vertical wall. Simulations are performed for the parameters, Richardson number (0, 0.25, 0.5, and 1), Reynolds number (380–550), Hartmann number (0, 10, 20, and 50) and dimensionless gap between the cylinders 0.1, 0.2, and 0.3. The analysis indicates that the transport process is a complex function of the magnetic field strength, mixed convective strength and the cylinder distance. Some typical combinations of these controlling parameters may produce three different transport characteristics such as the steady state, periodic oscillatory, and chaotic. With a lower cylinder distance and higher mixed convective strength, the flow instability increases causing periodic and even chaotic oscillations, whereas the magnetic field due to its damping nature imparts stability to the flow resulting in a steady state flow condition.
Nomenclature
| B0 | = | magnetic field strength (Wb/m2) |
| cp | = | specific heat at constant pressure (J/kgK) |
| d | = | cylinder diameter (m) |
| D | = | dimensionless cylinder diameter ( = d/L) |
| g | = | gravitational acceleration (m/s2) |
| Gr | = | Grashof number |
| H | = | height of square enclosure (m) |
| Ha | = | Hartmann number |
| k | = | thermal conductivity (W/mK) |
| L | = | width of square enclosure (m) |
| n1, n2, n3 | = | normal directions |
| N | = | interaction parameter |
| Nu | = | time and surface average Nusselt number (eq. Equation8 |
| Nuϕ | = | local Nusselt number (eq. Equation6 |
| = | time average local Nusselt number (eq. Equation7 | |
| p | = | pressure (N/m2) |
| P | = | dimensionless pressure ( = p + ρgy/ρu2i) |
| Pr | = | Prandtl number ( = ν/α) |
| Re | = | Reynolds number |
| Rem | = | magnetic Reynolds number ( = uiL/η) |
| Ri | = | Richardson number |
| s | = | gap between the cylinders (m) |
| S | = | dimensionless gap between the cylinders ( = s/L) |
| t | = | time (s) |
| tp | = | time period (s) |
| T | = | temperature (K) |
| u, v | = | velocity components (m/s) |
| U, V | = | dimensionless velocity components ( = u/ui, v/ui) |
| x, y | = | Cartesian coordinates (m) |
| X, Y | = | dimensionless Cartesian coordinates ( = x/L, y/L) |
Greek symbols
| α | = | thermal diffusivity (m2/s) |
| β | = | thermal expansion coefficient (1/K) |
| ϕ | = | cylinder surface (m) |
| η | = | magnetic diffusivity (m2/s) |
| θ | = | dimensionless temperature ( = (T − Ti)/(TH − Ti)) |
| ρ | = | density of fluid (kg/m3) |
| σ | = | electrical conductivity (1/Ω m) |
| = | kinematic viscosity of fluid (m2/s) | |
| τ | = | dimensionless time (= tui/L) |
Subscripts
| i | = | inlet |
| H | = | hot |
Additional information
Notes on contributors
Dipankar Chatterjee
Dipankar Chatterjee is a Senior Scientist in CSIR-Central Mechanical Engineering Research Institute, India. He received his PhD from Indian Institute of Technology Kharagpur, India. He has published around 100 international journal papers. His main interests are computational modeling of fluid flow and heat transfer over bluff obstacles, turbulence, phase change and reactive flow process modeling, lattice Boltzmann modeling and electromagnetohydrodynamic interactions in macro and microflows.
Ramgopal Mishra
Ramgopal Mishra has recently completed M.Tech. in Mechanical Engineering from National Institute of Technology, Durgapur, India. He has received his B.Tech. in Mechanical Engineering from Sandip Foundation SITRC Nashik and University- University of Pune, India. He has interest to work in the field of computational fluid flow and heat transfer.