Page 234 - 48Fundamentals of Compressible Fluid Mechanics
P. 234

196     CHAPTER 11. EVACUATING AND FILLING A SEMI RIGID CHAMBERS




                                                                                                              (11.48)


                                                   Notice that when      (   :  >  equation (11.49) reduced to equation (11.43).


                                                                             < E

                                                                                      >
                                                   After carrying–out differentiation results
                                                                                 >
                                                                   >*
                                                                                                              (11.49)



                                                                    E
                                                   Again, similarly as before, variables are separated and integrated as fol-
                                                                 (
                                                                                   E

                                                                                          %
                                                                                          >

                                            lows
                                                                                 >

                                                                        >
                                                                                     >

                                                                                 >*


                                                                                                              (11.50)


                                                                  B


                                             Carrying–out the integration for the initial part if exit results in

                                                                              E

                                                                           (

                                                                                      >
                                                                                                >
                                                                                        >
                                                                   *

                                                                                                              (11.51)



                                             The linear condition are obtain when        E  >



                                                                        E E




                                                               >
                                                           >*    (
                                                                                                              (11.52)


                                                                                 E
                                             That is just bellow 1 (     (    1+ ) for  .
                                                                               (
                                                                                            E

                                                                    E E


                                                                     ), 9-)
                                            11.5     Advance Topics
                                                         is very large for small values of the entrance Mach number which
                                                                (

                                            requires keeping many digits in the calculation. For small values of the Mach num-
                                            The term
                                            bers, equation (??) can be approximated as
                                                                                                              (11.53)




                                             and equation (??) as             O B
                                                                                    E

                                                                                U
                                                                                 O B
                                                                                 U
                                                                                                              (11.54)


                                             The solution of the last two equations yields  U  O B

                                                                           *
                                                                           U
                                                                            O B



                                                                                                              (11.55)





                                                                                     & B
                                                                                 E
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