Page 135 - 48Fundamentals of Compressible Fluid Mechanics
P. 135

5.4. SHOCK TUBE                                                      97

         Or in-terms of the pressure ratio is




                                                                           (5.81)











         As it was mentioned earlier the velocity at points  and 3 are identical, hence
                                                   "
         equation (5.81) and equation (5.75) can be combined to yield



                                                                           (5.82)





                                                    %




                                                               %











         After some rearrangement equation (5.82) transformed into 	   %
                                                              %
                                     "



                                                                           (5.83)


















                                        ,


                                               #



         Or in terms of Mach number of the




                                                                           (5.84)













                                   
   &





         Utilizing the Rankine–Hugoniot relationship and the perfect gas model results in


                                            %

                                                %
                                                                 (
                                                                           (5.85)


                                              %

                                     
  %



                                              %



         Utilizing the isentropic relationship for zone 3-5 results in
                                              %


                                                                           (5.86)
















                                                     "
         Example 5.7:
                                                                                .

         Find what is the shock velocity, temperature behind the shock. what will be tem-
         A shock tube with initial pressure ratio of
                                                  and the initial temperature of
                                                         ?


         perature behind the shock if the pressure ratio is
          SOLUTION
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