Example of the Method of Reduction

 

 

Example (cont)

 

The general solution from the method of reduction is:  y(r)  =  C1r  +  C2/r

 

Recall that the inner cylinder has radius, a, and the outer cylinder has radius, b.  Apply

the boundary conditions.

 

                                    y(a) =  a ω     and   y(b)  =  0                                    

 

 

                  C1b +  C2/b = 0   and  C1 a +  C2/a  =  a ω

 

The solution for C1  and  C2  is:

 

                                                       C1  =  - a2 ω/ [ b2  -  a2 ]

 

                                                       C2  =    a2 b2 ω/ [ b2  -  a2 ]

 

 

 

               y(r)  =   - a2 ω r / [b2 - a2 ]   +   a2 (b2/r)ω / [b2 - a2 ]  

 

 

                y(r)  =  a2 ω [ b2/r  -  r) / [  b2 -  a2 ]                        (result)

 

     

 

 


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