[![Lift Airbus vs Blended Wing][1]][1]

 - The Burnelli machines had an airfoil shaped fuselage;  
   
 - some indicate near 10% of lift in a 21 century airliner comes from
   fuselage;    'Flying Wing' concept is old, and still attracts many;  
   
 - bottom of SR-71 looks shapen as a high speed race boat;  
   
 - at very high speeds, air is thick, not as a brick, but as
   'marmelade', it's a Reynolds Number affair, this figure, you know,
   expresses relations of inertia and viscosity forces inside a fluid.

Would a flat bottomed fuselage add even more lift than the regular round section, increasing the overall fuel economy of an airplane? Does the concept deserve Aerodynamic Wind Tunnel testing?
 
[![Proposed shape for fuselage, fins may act as 'Winglets'][2]]


  [1]: https://i.sstatic.net/t6RA1.png
  [2]: https://i.sstatic.net/wyrf4.jpg