Aerodynamic Performance of Wing-Body Configurations and the Flying Wing

An elementary analysis has been made of generic wing-body configurations with variable volume allotment in wing and body, for constant total useful volume, including the all-wing configuration. These aircraft were compared on the basis of the Lift-to-Drag (L/D) ratio, for specified flight conditions. In addition the parameter ML/D for constant corrected thrust has been optimized, resulting in certain combinations of altitude and speed for maximum specific range (if corrected TSFC = constant). Finally, the effect of volume allotment on L/D for given engine size was studied. It has been found that in many cases optimum volume allotments indicate that wing-body combinations are to be favored. Only in the case of relatively low Mach numbers and high-altitude flight the flying wing outperforms conventional aircraft, but it will generally require larger engines.