Langley Research Center historian, James R. Hansen, wrote that the VDT provided results superior to the atmospheric wind tunnels used at the time and was responsible for making NACA, the precursor to NASA, "a world leader in aerodynamic research".

The Reynolds number is defined as[4] where: The wind tunnels that were used before the creation of the VDT could only operate at normal atmospheric pressures.

If a full-scale airfoil is to be simulated in a wind tunnel by a small-scale model, the Reynolds number can only be matched by increasing the velocity or its density or by decreasing its viscosity.

[5] In 1920, the National Advisory Committee for Aeronautics brought Max Munk, a German aerospace engineer and student of Ludwig Prandtl at University of Göttingen, to work for them in America.

The variable-density wind tunnel had a closed-circuit design with an annular return flow to minimize the volume of the tank.

The VDT re-entered service in 1930 and continued to aid the Langley staff in measuring the aerodynamic qualities of airfoils until it was deemed obsolete in the 1940s and converted into a pressure tank for other wind tunnels.

[1][9] This data was used in designing American World War II aircraft such as the Douglas DC-3, the Boeing B-17 Flying Fortress, and the Lockheed P-38 Lightning.