Arthur Robert Kantrowitz (October 20, 1913 – November 29, 2008) was an American

scientist A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosoph ...

engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limit ...

, and educator. Kantrowitz grew up in

The Bronx The Bronx () is a borough of New York City, coextensive with Bronx County, in the state of New York. It is south of Westchester County; north and east of the New York City borough of Manhattan, across the Harlem River; and north of the New Y ...

and graduated from

DeWitt Clinton High School , motto_translation = Without Work Nothing Is Accomplished , image = DeWitt Clinton High School front entrance IMG 7441 HLG.jpg , seal_image = File:Clinton News.JPG , seal_size = 124px , ...

.Overbye, Dennis
"Arthur R. Kantrowitz, Whose Wide-Ranging Research Had Many Applications, Is Dead at 95"
''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid d ...

'', December 9, 2008. Accessed December 9, 2008. He earned his B.S., M.A. and, in 1947, his Ph.D. degrees in

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

from

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

Early life

Kantrowitz was born in New York City on October 28, 1913. His mother was a costume designer and his father ran a clinic in

the Bronx The Bronx () is a borough of New York City, coextensive with Bronx County, in the state of New York. It is south of Westchester County; north and east of the New York City borough of Manhattan, across the Harlem River; and north of the New Y ...

. As a child, Arthur built an electrocardiograph from old radio parts, working with his brother

Adrian Adrian is a form of the Latin given name Adrianus or Hadrianus. Its ultimate origin is most likely via the former river Adria from the Venetic and Illyrian word ''adur'', meaning "sea" or "water". The Adria was until the 8th century BC the mai ...

(who would go on to perform the first

heart transplant A heart transplant, or a cardiac transplant, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease when other medical or surgical treatments have failed. , the most common procedu ...

in the United States.)Hoffman, Jascha
"Dr. Adrian Kantrowitz, Cardiac Pioneer, Dies at 90"
''

'', November 19, 2008. Accessed November 19, 2008.

Career

During his graduate studies at Columbia, Kantrowitz started working as a physicist in 1936 for the

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

(NACA), work he would continue for ten years. While obtaining his Ph.D., Kantrowitz was supervised by

Edward Teller Edward Teller ( hu, Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care for ...

. He went on to teach at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...

for the next ten years and later founded the Avco-Everett Research Lab (AERL) in Everett, Massachusetts, in 1955. He developed

shock tube : ''For the pyrotechnic initiator, see Shock tube detonator'' The shock tube is an instrument used to replicate and direct blast waves at a sensor or a model in order to simulate actual explosions and their effects, usually on a smaller scale. ...

s, which were able to produce the extremely hot gases needed to simulate atmospheric re-entry from orbital speeds, thereby solving the critical nose cone re-entry heating problem and accelerating the development of recoverable spacecraft. He was AERL's director, chief executive officer, and chairman until 1978 when he took on a professorship at

Dartmouth College Dartmouth College (; ) is a private research university in Hanover, New Hampshire. Established in 1769 by Eleazar Wheelock, it is one of the nine colonial colleges chartered before the American Revolution. Although founded to educate Native ...

. From 1956 to 1978 he also served as a vice president and director of Avco Corporation.

Scientific contributions

Kantrowitz's interdisciplinary research in the area of

fluid mechanics Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them. It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and ...

and

gas dynamics Compressible flow (or gas dynamics) is the branch of fluid mechanics that deals with flows having significant changes in fluid density. While all flows are compressible, flows are usually treated as being incompressible when the Mach number (the ...

led to contributions in the field of

magnetohydrodynamics Magnetohydrodynamics (MHD; also called magneto-fluid dynamics or hydromagnetics) is the study of the magnetic properties and behaviour of electrically conducting fluids. Examples of such magnetofluids include plasmas, liquid metals, ...

and to the development of high-efficiency, high-power

lasers A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...

. He first suggested a system of

laser propulsion Laser propulsion is a form of beam-powered propulsion where the energy source is a remote (usually ground-based) laser system and separate from the reaction mass. This form of propulsion differs from a conventional chemical rocket where both energ ...

to launch bulk payloads into orbit, using energy from ground-based lasers to increase exhaust velocity and thereby reduce the propellant-to-payload mass ratio. His concepts on laser propulsion were published in 1988. His early research included supersonic diffusers and supersonic compressors in the early 40s, which has since been applied to jet engines. He invented the

total energy variometer In aviation, a variometer – also known as a rate of climb and descent indicator (RCDI), rate-of-climb indicator, vertical speed indicator (VSI), or vertical velocity indicator (VVI) – is one of the flight instruments in an aircraft used to i ...

in 1939, used in soaring planes, and is the co-inventor of an early scheme for magnetically contained

nuclear fusion Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manife ...

, patent application, 1941. In 1950, he invented a technique for producing the supersonic source for molecular beams; this was subsequently used by chemists in research that led to two

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

s. In the 1960s and 1970s, he led the design and development at AERL of the first

intra-aortic balloon pump The intra-aortic balloon pump (IABP) is a mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output through afterload reduction. It consists of a cylindrical polyurethane balloon that sits in the aorta ...

. The balloon pump is a temporary cardiac assist device which has been used worldwide on three million people. The device was used on his own failing heart. Another contribution to science was the stagnation-point flow experiment in which processes of initial interaction of fresh flowing blood with an artificial surface can be directly visualized under a high-power microscope. This technique has become an important method for experimentally studying this vital interaction and led to a variety of circulatory prostheses, including the artificial heart. Kantrowitz, as an advocate of the separation of science and technology from political or ideological concerns, first proposed in 1967 the creation of an Institution for Scientific Judgment, commonly referred to as the Science Court, to assess the state of knowledge in

scientific controversies Controversies involving science exists in all aspects. Sometimes defined as a "''persistent disagreement''" over knowledge, the contrasting opinions of certain topics leaves individuals in a tense setting. A scientific controversy is a substanti ...

of importance to public policy. He further developed the Science Court as its Task Force Chairman in President Ford's Advisory Group on Anticipated Advances in Science and Technology, 1975–1976. According to

Jerry Pournelle Jerry Eugene Pournelle (; August 7, 1933 – September 8, 2017) was an American scientist in the area of operations research and human factors research, a science fiction writer, essayist, journalist, and one of the first bloggers. In the 1960s ...

, "We could have developed all this .e. large scale commercial space developmentin the 60s and 70s, but we went another path. Arthur Kantrowitz tried to convince Kennedy's people that the best way to the Moon was through development of manned space access, a von Braun manned space station, and on to the Moon in a logical way that left developed space assets."

Kantrowitz limit

Kantrowitz is known for development of a theoretical concept of fluid choke points at supersonic and near-supersonic inlet velocities. The concept has become known as the Kantrowitz limit.

Technical description

Applications

The Kantrowitz limit has many applications in the

of inlet flow for jet engines and

rockets A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

, both when operating at high-subsonic and supersonic velocities. Two examples will explain the effect of the Kantrowitz Limit on a nozzle. For both cases,

Mass flow rate In physics and engineering, mass flow rate is the mass of a substance which passes per unit of time. Its unit is kilogram per second in SI units, and slug per second or pound per second in US customary units. The common symbol is \dot ('' ...

= Inlet Velocity multiplied by Area multiplied by Density. Consider a nozzle connected to a vacuum source. As the pressure ratio gets to about 2, the flow through the nozzle will approach the local speed of sound, and the flow becomes

choked flow Choked flow is a compressible flow effect. The parameter that becomes "choked" or "limited" is the fluid velocity. Choked flow is a fluid dynamic condition associated with the venturi effect. When a flowing fluid at a given pressure and temperatu ...

. When the absolute pressure of the vacuum is decreased further, the flow speed will not increase. This is the Kantrowitz Limit, which limits the mass flow because the velocity is limited to the speed of sound, and the area, inlet pressure and density are all fixed. Aircraft jet engines are very much affected by this limit, once the inlet flow speed gets to Mach 1 the mass flow rate is limited, regardless of how much suction the engine creates. Next, consider the nozzle connected to a compressed air supply. With a pressure ratio of about 2, the flow becomes choked, and cannot exceed the speed of sound. But the density and resultant mass flow rate can be increased by increasing the inlet pressure. The greater the pressure, the greater the density, and the greater the mass flow. So, while Kantrowitz limits the maximum gas velocity, it does not apply any fixed limit to the mass flow rate. A recent high-speed transportation option for rapid transit between populous city-pairs about apart, the

Hyperloop A hyperloop is a proposed high-speed transportion system for both public and goods transport. The idea was picked up by Elon Musk to describe a modern project based on the vactrain concept (first appearance in 1799). Hyperloop systems compri ...

, has the Kantrowitz limit as a fundamental design criterion. Attempting to pass a high-speed passenger-pod through a very low pressure tube runs squarely into the Kantrowitz fluid flow limit. Historically, the solutions to working within the limit have been "go fast" and "go slow". A major innovation in the Hyperloop proposal provides a novel third approach to remain below the Kantrowitz limit while still moving at high-subsonic velocities: adding a front-end inlet compressor to actively transfer high-pressure air from the front to the rear of the high-speed transport capsule, and thus bypassing much of the air that would have resulted in the dynamic shock of the

. The flow in the smaller duct through the capsule is also subject to the Kantrowitz Limit, this is relieved by increasing the pressure and the density to achieve the required mass flow. In the Hyperloop alpha design of 2013, the air-inlet pump also provides a low-friction air-bearing suspension system for traveling at over .

Honors and awards

Kantrowitz was a fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

, American Association for the Advancement of Science, American Astronautical Society, American Institute of Aeronautics and Astronautics (honorary), American Physical Society, American Institute for Medical and Biological Engineering and member of the

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of ...

and National Academy of Sciences and International Academy of Astronautics. In 1953–1954, he held both Fulbright and Guggenheim Fellowships at Cambridge and Manchester Universities. Kantrowitz was an honorary trustee of the University of Rochester, an honorary life member of the Board of Governors of The Technion, and an honorary professor of the Huazhong Institute of Technology, Wuhan, China. Kantrowitz also served on the Board of Advisors for the

Foresight Institute The Foresight Institute (Foresight) is a San Francisco-based research non-profit that promotes the development of nanotechnology and other emerging technologies, such as safe AGI, biotech and longevity. Foresight runs four cross-disciplinary pr ...

, an organization devoted to preparing for nanotechnology. Kantrowitz held 21 patents and wrote or co-authored more than 200 scientific and professional papers and articles. He also co-authored ''Fundamentals of Gas Dynamics'', 1958, Princeton Univ. Press. Kantrowitz died at age 95, November 29, 2008, while visiting relatives in New York. He had suffered a

heart attack A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ma ...

on the previous day.

References

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External links

* * * * {{DEFAULTSORT:Kantrowitz, Arthur 1913 births 2008 deaths Members of the United States National Academy of Sciences Engineers from New York (state) Cornell University faculty Thayer School of Engineering faculty Jewish scientists DeWitt Clinton High School alumni 20th-century American engineers Fellows of the American Physical Society Columbia University School of General Studies alumni Columbia Graduate School of Arts and Sciences alumni