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204                           6.  Inviscid  Flow  Equations  for  Incompressible  Flows



         6C.2  Subroutine  COEF

         This  subroutine  is  modified  according  to  Eqs.  (6.5.2)  and  (6.5.4).


         6C.3  Subroutine  VPDIS
         This  subroutine  is  also  modified  to  take  into  account  the  distribution  of  all  the
         sources  and  vorticities  from  each  element.


         6C.4  Subroutine  CLCM

         In  this  subroutine,  the  lift  CL  and  pitching  moment  CM  coefficients  of  each
         element  are  first  determined  and  then  the  total  lift  CLT  and  total  pitching
         moment  CMT  coefficients  are  calculated  by  adding  together  the  coefficients  of
         each  element.



         R e f e r e n c e s

         [1]  Hess, J. L. and  Smith,  A. M. O.:  "Calculation  of Potential  Flow  About  Arbitrary  Bod-
            ies,"  Progress  in  Aerospace  Sciences,  Vol.  5,  Pergamon  Press,  N.Y.,  1966.
         [2]  Anderson,  J.D.:  Fundamentals  of  Aerodynamics,  McGraw  Hill,  Inc.,  N.Y.,  1991.
         [3]  Abbott,  J.H.  and  von  Doenhoff,  A.E.:  Theory  of  Wing  Sections,  Dover,  1959.
         [4]  Cebeci,  T.,  An  Engineering  Approach  to  the  Calculation  of  Aerodynamic  Flows,  Hori-
            zons  Pub.,  Long  Beach,  Calif.,  and  Springer,  Heidelberg,  1999.


         P r o b l e m s


         6-1.  Consider  a two-dimensional,  steady,  fully-developed  laminar  flow  in  a  chan-
        nel  of  rectangular  cross-section  with  a  width  of  2L  in  the  ^-direction  and  the
        distance  between  upper  and  lower  surfaces  zl.  Determine  the  velocity  distribu-
        tion  by  the  direct  method  discussed  in  subsection  4.5.1  by  solving


                                     \i dx   I  dx 2  dy 2  J

         subject  to  the  boundary  conditions  in  one  symmetric  quadrant  of the  flow

                                du(0,z
                                        =  0,   u(l,z)  =  0             (P6.1.2a)
                                  dy
                                du(v,0)
                                        =  0,   u(y,L)  =  Q             (P6.1.2b)
                                  dz
         Hint:  First  express  the  above  equations  in  dimensionless  form  by  defining
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