Page 204 - Fundamentals of The Finite Element Method for Heat and Fluid Flow
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CONVECTION HEAT TRANSFER
                        196
                                     0.8 1                      Standard Galerkin
                                                             Characteristic Galerkin
                                                                   Exact solution
                                     0.6
                                    Function  0.4



                                     0.2


                                      0

                                       0        0.2      0.4      0.6       0.8       1
                                                         Horizontal distance
                                                           (a) Pe = 1.0
                                      1

                                     0.8                        Standard Galerkin
                                                             Characteristic Galerkin
                                                                   Exact solution
                                     0.6
                                    Function  0.4





                                     0.2

                                      0

                                       0        0.2      0.4      0.6       0.8       1
                                                         Horizontal distance
                                                           (b) Pe = 1.5
                        Figure 7.11 Spatial variation of a function, φ, in one-dimensional space for different
                        element Peclet numbers


                        without the source term is
                                      ∂φ     ∂φ      ∂φ     ∂     ∂φ     ∂     ∂φ
                                         + u 1   + u 2   =      k     +      k             (7.105)
                                      ∂t     ∂x 1    ∂x 2  ∂x 1  ∂x 1   ∂x 1  ∂x 2
                           The convection velocity components u 1 and u 2 are assumed to be constant in deriving
                        this equation. Applying the characteristic Galerkin procedure to the above equation, we
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