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Spessore di spostamento


$ \displaystyle \delta^*$ $\displaystyle =$ $\displaystyle \int_0^\infty{\left(1-\frac{u}{U}\right)dy}$  
  $\displaystyle =$ $\displaystyle \int_0^\infty{\left(1-\frac{x f'}{k x}\right)\sqrt{\frac{\nu}{k}}d\eta}$  
  $\displaystyle =$ $\displaystyle \sqrt{\frac{\nu}{k}}\int_0^\infty{\left(1-\frac{k F'}{k }\right)d\eta}$  
  $\displaystyle =$ $\displaystyle \sqrt{\frac{\nu}{k}}\int_0^\infty{\left(1-F'\right)d\eta}$  
  $\displaystyle =$ $\displaystyle 0.648\sqrt{\frac{\nu}{k}}$  
  $\displaystyle =$ $\displaystyle 0.648\sqrt{\frac{\nu x^2}{k x^2}}$  
  $\displaystyle =$ $\displaystyle 0.648\ x\ \sqrt{\frac{\nu}{U x}}$  
  $\displaystyle =$ $\displaystyle 0.648\ x\ \frac{1}{\sqrt{\mathcal{R}e_x}}$  

$\displaystyle \frac{\delta^*}{x}\sqrt{\mathcal{R}e_x}=0.648$ (8.9)



2009-01-26