Introduction to this special issue on hypersonics

摘要

In the waning days of World War Ⅱ, U.S. Army General Hap Arnold was leading the creation of a separate Air Force, to be born from the U.S. Army Air Corp that had so completely dominated the skies over Europe and the Pacific. As commander of the US Army Air Forces, Arnold recognized the role that technology had played in defeating Nazi Germany and Imperial Japan. The development of long range bombers, culminating in the remarkable B-29, as well as high-performance fighters such as the P-51, with its clean aerodynamics and Merlin engine, were critical to allied successes. Yet at the same time, there is evidence that Arnold realized that the United States had missed some key technology developments, including the gas turbine engine, and had ultimately won the war not because of technological superiority, but because of superior manufacturing and logistics.