Eastman Jacobs (1902–1987) was a leading American

aerodynamicist Aerodynamics () is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an important domain of ...

who worked for

NACA The National Advisory Committee for Aeronautics (NACA) was a United States federal agency that was founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its ...

's Langley Memorial Aeronautical Laboratory (renamed

NASA Langley Research Center The Langley Research Center (LaRC or NASA Langley), located in Hampton, Virginia, near the Chesapeake Bay front of Langley Air Force Base, is the oldest of NASA's field centers. LaRC has focused primarily on aeronautical research but has also ...

in 1958) from the 1920s to the 1940s. He was responsible for advancing many fields in aerodynamics, dealing particularly with

wind tunnels A wind tunnel is "an apparatus for producing a controlled stream of air for conducting aerodynamic experiments". The experiment is conducted in the test section of the wind tunnel and a complete tunnel configuration includes air ducting to and f ...

airfoils An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more lift than drag. Wings, sails and propeller blades are examples of airfoils. Foils of similar function designed ...

turbulence In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between ...

boundary layers In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a no-slip boundary condi ...

, and

Schlieren photography Schlieren photography is a process for photographing fluid flow. Invented by the Germans, German physicist August Toepler in 1864 to study supersonic motion, it is widely used in aeronautical engineering to photograph the airflow, flow of air ar ...

Biography

Eastman Jacobs joined NACA in 1925 after earning a bachelor's degree in Electrical Engineering at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

. He applied at the Bell Labs but was not accepted and opted for his second choice Langley. His knowledge of complex analysis was key to current airfoil design techniques at the time. He quickly became one of the leading scientists at the Langley Research Center due to his work with optimizing airfoils using a variable density wind tunnel that could operate with high

Reynolds number In fluid dynamics, the Reynolds number () is a dimensionless quantity that helps predict fluid flow patterns in different situations by measuring the ratio between Inertia, inertial and viscous forces. At low Reynolds numbers, flows tend to ...

s. He was also officially the head of the Variable Density Wind Tunnel Division from 1928-1939. He and his colleagues were able to significantly reduce the turbulence in the wind tunnel, which led to a better understanding of boundary development around airfoil sections. A better knowledge of boundary layer growth then led to an optimization scheme for low-drag

laminar flow Laminar flow () is the property of fluid particles in fluid dynamics to follow smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral m ...

airfoils. This optimization scheme produced the NACA 4-digit airfoils that led to faster aircraft like the

P-51 Mustang The North American Aviation P-51 Mustang is an American long-range, single-seat fighter aircraft, fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in 1940 by a team headed ...

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. In 1937, he received the Sylvanus Albert Reed Award for his improvement of airfoils. By the 1930s, Jacobs became interested in high-speed wind tunnels, and helped to build one of the first in the United States. He became the first person to observe a

shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

propagating over an airfoil using Schlieren photography. In 1935, he was invited to the now famous fifth Volta conference on aerodynamics titled "High Velocities in Aviation". There, he gave a presentation on high-speed wind tunnels and his Schlieren images which exposed the technology to the rest of the world. Later in his career, he designed a

motorjet A motorjet is a rudimentary type of jet engine which is sometimes referred to as ''thermojet'', a term now commonly used to describe a particular and completely unrelated pulsejet design. Design At the heart the motorjet is an ordinary pist ...

aircraft referred to "Jake's Jeep", but this work was canceled by the NACA. He retired at an early age of 42 in 1944. A restaurant he started in 1958, called "Panorama Pacific at Solimar," on his property near the Pacific Coast Highway on the Ventura-

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

county line in Malibu, became known throughout the 1960s as "Jake's Diner." The restaurant survives today as "

Neptune's Net Neptune's Net is a seafood restaurant in Malibu, California. The landmark has been featured in countless television and film productions. History In 1956, the site began as a gas station, real-estate office, and restaurant called Panorama Pacif ...

". Jacobs died June 21, 1987 and his ashes were spread on his ranch property.NASA Entry for Eastman N. "Jake" Jacobs
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Awards

* Wright Brothers Medal – 1933

References

External links

NACA 4-digit series airfoil generator
{{DEFAULTSORT:Jacobs, Eastman 1902 births 1987 deaths Aerodynamicists American mechanical engineers 20th-century American engineers

Biography

Awards

See also

References

External links