![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
Natural convection in a cylinder with an internally slotted annulus was solved by SIMPLE algorithm, and the effects of different slotted structures on the nonlinear characteristics of natural convection were investigated. The results show that the equivalent thermal conductivity Keq increases with Rayleigh number, and reaches the maximum in the vertical orientation. Nonlinear results were obtained by simulating the fluid flow at different conditions. With increasing Rayleigh number, heat transfer is intensified and the state of heat transfer changes from steady to unsteady. We investigated the effects of different slotted structures on natural convection and analyzed the corresponding nonlinear characteristics.
Nomenclature
| cp | = | specific heat (J/kgK) |
| F | = | nondimensional time |
| g | = | gravitational acceleration (m/s2) |
| p | = | pressure (Pa) |
| P | = | nondimensional pressure |
| Pr | = | Prandtl number |
| Q | = | heat generation by the heaters (W/m) |
| Ra | = | Rayleigh number |
| r | = | radial coordinate |
| R | = | nondimensional radial coordinate |
| ri | = | radius of inner slotted cylinder (m) |
| ro | = | radius of outer cylinder (m) |
| S | = | nondimensional internal heat generation |
| t | = | time (s) |
| T | = | temperature (K) |
| To | = | temperature of outer walls (K) |
| Ti | = | temperature of inner walls (K) |
| U | = | nondimensional velocity in the radial coordinate |
| vr | = | radial velocity |
| vθ | = | tangential velocity |
| V | = | nondimensional velocity in the tangential coordinate |
| Greek symbols | = | |
| ϕ | = | angle of slot from the vertical (rad) |
| μ | = | viscosity (Kg/ms) |
| ρ | = | density (Kg/m3) |
| Θ | = | nondimensional temperature |
| θ | = | angular coordinate |
| Δτ | = | nondimensional time step |
| σ | = | thermal diffusivity (m2/s) |
| β | = | thermal expansion coefficient (1/K) |
| δ | = | thickness of the inner cylinder |
Nomenclature
| cp | = | specific heat (J/kgK) |
| F | = | nondimensional time |
| g | = | gravitational acceleration (m/s2) |
| p | = | pressure (Pa) |
| P | = | nondimensional pressure |
| Pr | = | Prandtl number |
| Q | = | heat generation by the heaters (W/m) |
| Ra | = | Rayleigh number |
| r | = | radial coordinate |
| R | = | nondimensional radial coordinate |
| ri | = | radius of inner slotted cylinder (m) |
| ro | = | radius of outer cylinder (m) |
| S | = | nondimensional internal heat generation |
| t | = | time (s) |
| T | = | temperature (K) |
| To | = | temperature of outer walls (K) |
| Ti | = | temperature of inner walls (K) |
| U | = | nondimensional velocity in the radial coordinate |
| vr | = | radial velocity |
| vθ | = | tangential velocity |
| V | = | nondimensional velocity in the tangential coordinate |
| Greek symbols | = | |
| ϕ | = | angle of slot from the vertical (rad) |
| μ | = | viscosity (Kg/ms) |
| ρ | = | density (Kg/m3) |
| Θ | = | nondimensional temperature |
| θ | = | angular coordinate |
| Δτ | = | nondimensional time step |
| σ | = | thermal diffusivity (m2/s) |
| β | = | thermal expansion coefficient (1/K) |
| δ | = | thickness of the inner cylinder |