Abstract:
The graphical behavior of laminar natural conve.ction of an incompressible and
Newtonian fluid in an enclosure are studied by using Computer Aided Fluid Flow
Analysis (CAFFA). Hydrodynamic and thermal behavior of fluid along with heat transfer
irreversibility inside two isothermally heated surfaces are predicted. The lower surface is
flat plate which is kept hot and the upper plate is a wavy surface which is kept cold. Two
vertical plates are considered adiabatic. The mathematical formulation of the problem
considered in terms of continuity, momentum, and the energy equations, and the pertinent
boundary conditions for a wavy domain containing one wavy upper wall and three flat
walls. For two-dimensional laminar natural convection, the non-dimensional equations
governing the conservation of mass, momentum and energy in the enclosure are used.
Finite-volume method is used to discretize the governing differential equations with nonstaggered
variable arrangement. Second law of thermodynamics is applied to predict the
nature of irreversibility in terms of entropy generation. TDMA solver is used to solve the
algebraic equations. Time integration is done using three time level method. Iteration is
continued until the difference between two consecutive field values of variables is less
than or equal to 10-5 Time dependent simulations are performed for several Reynolds
number. Rate of heat transfer in terms of local and global Nusselt numbers are calculated
for different Rayleigh numbers. Flow and thermal fields are analyzed by parametric
presentation of streamlines and isothermal lines.
