638
P. Liu
Fig. 8.49 Bacheler (1920–2000)
In 1967, he put forward supercritical airfoil, which delayed the generation
of local shock wave, greatly increased the drag divergence Mach number of
airfoil, increased the cruising speed of subsonic aircraft and reduced fuel
consumption. At present, all kinds of high subsonic aircraft in the world
adopt this kind of similar airfoil, which has become one of the core technologies of wing design, and Whitcomb had also won the Collier aviation
award. In the mid-1970s, Whitcomb invented winglets, and through a series
of wind tunnel tests, it was found that the wing with such winglets could
indeed reduce drag. The results of wind tunnel test and flight test show that
the winglets can reduce the induced drag of the whole aircraft by 20–35%,
which is equivalent to the increase of lift–drag ratio by 5–7% (Fig. 8.50).
8.51 Lighthill (1924–1998)
Michael James Lighthill (1924–1998) is a famous British mathematician and
hydrologist. He was mainly engaged in the scientific work in the fields of fluid
mechanics, applied mathematics, etc. He had created the new subject fields of
aeroacoustics, nonlinear acoustics and biological fluid dynamics, created the
theory of aeroacoustics, and made an important contribution to the reduction
P. Liu
Fig. 8.49 Bacheler (1920–2000)
In 1967, he put forward supercritical airfoil, which delayed the generation
of local shock wave, greatly increased the drag divergence Mach number of
airfoil, increased the cruising speed of subsonic aircraft and reduced fuel
consumption. At present, all kinds of high subsonic aircraft in the world
adopt this kind of similar airfoil, which has become one of the core technologies of wing design, and Whitcomb had also won the Collier aviation
award. In the mid-1970s, Whitcomb invented winglets, and through a series
of wind tunnel tests, it was found that the wing with such winglets could
indeed reduce drag. The results of wind tunnel test and flight test show that
the winglets can reduce the induced drag of the whole aircraft by 20–35%,
which is equivalent to the increase of lift–drag ratio by 5–7% (Fig. 8.50).
8.51 Lighthill (1924–1998)
Michael James Lighthill (1924–1998) is a famous British mathematician and
hydrologist. He was mainly engaged in the scientific work in the fields of fluid
mechanics, applied mathematics, etc. He had created the new subject fields of
aeroacoustics, nonlinear acoustics and biological fluid dynamics, created the
theory of aeroacoustics, and made an important contribution to the reduction