Abstract: Two-dimensional heat conduction within a composed solid material with a constant internal heat generation has been investigated numerically in a sector of the rotor a generator. The heat transfer between two adjacent materials is assumed to be purely conduction. Boundary conditions are assumed to be forced convection on the fluid side and adiabatic on symmetry lines. The control volume method is applied for the diffusion energy equation. Physical coordinates are transformed to the general curvilinear coordinates. Then by using a line-by-line method, the temperature distribution in a sector of the rotor has been determined. Finally, the results are normalized and the effect of cooling fluid on the maximum temperature of insulation is investigated.
Abstract: Nowadays, there is little information, concerning the
heat shield systems, and this information is not completely reliable to
use in so many cases. for example, the precise calculation cannot be
done for various materials. In addition, the real scale test has two
disadvantages: high cost and low flexibility, and for each case we
must perform a new test. Hence, using numerical modeling program
that calculates the surface recession rate and interior temperature
distribution is necessary. Also, numerical solution of governing
equation for non-charring material ablation is presented in order to
anticipate the recession rate and the heat response of non-charring
heat shields. the governing equation is nonlinear and the Newton-
Rafson method along with TDMA algorithm is used to solve this
nonlinear equation system. Using Newton- Rafson method for
solving the governing equation is one of the advantages of the
solving method because this method is simple and it can be easily
generalized to more difficult problems. The obtained results
compared with reliable sources in order to examine the accuracy of
compiling code.
Abstract: In this study, the numerical solution of unsteady flow
between two concentric rotating spheres with suction and blowing at
their boundaries is presented. The spheres are rotating about a
common axis of rotation while their angular velocities are constant.
The Navier-Stokes equations are solved by employing the finite
difference method and implicit scheme. The resulting flow patterns
are presented for various values of the flow parameters including
rotational Reynolds number Re , and a blowing/suction Reynolds
number Rew . Viscous torques at the inner and the outer spheres are
calculated, too. It is seen that increasing the amount of suction and
blowing decrease the size of eddies generated in the annulus.