most of the boundary-layer edge of T, u > 0. In the region of the rear of 

 the body and the near wake, there would be some pressure recovery (especial- 

 ly if separation has not occurred) and u on T would there become negative, 

 and gradually approach zero with increasing downstream distance. This 

 suggests that u in (89) and u in (86) are negative. Since the difference 

 in heads, H_ - H , contributes about 90 percent of the magnitude of the 



integrand in (88) and (89), and u„ << U„, (89) may be written as 



kj u 



°2 ■=• I (l+ ^) / '^%-V ^S - f J (-E-%) 



2dS 



which yields 



D^ - D^ = p ^ f g(Ho-Hj dS - p f u^(u^-u 



51 



-u ) dS 



= p- I [g(HQ-Hj-UQ(u^-uJ] dS (90) 



Applying the expression for H in (85) and 



PS «0 = Pe + i P%-^E>^ 



2 2 

 in (90) and neglecting the term u - u , we obtain 



E m 



°2 - °1 '^^ ^ [ (PE-Pm) ''^ > ^'^^ 



34 



