Paul Bevilaqua is an aeronautics engineer at

Lockheed Martin The Lockheed Martin Corporation is an American aerospace, arms, defense, information security, and technology corporation with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It ...

in California. In 1990, he invented the

lift fan Lift fan is an aircraft configuration in which lifting fans are located in large holes in an otherwise conventional fixed wing or fuselage. It is used for V/STOL operation. The aircraft takes off using the fans to provide lift, then transitions ...

for the Joint Strike Fighter F-35B along with fellow

Skunk Works Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, beginning with the Lockheed P-38 Lightn ...

engineer Paul Shumpert. In 2005, Bevilaqua was elected as a 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 ...

for his theoretical contributions, practical innovations, and increased operational utility in vertical takeoff and landing aircraft.

Life and career

Paul Bevilaqua earned a

Doctorate A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism ''l ...

Aeronautics Aeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies ...

and Astronautics (subject:

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

wakes) at

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money ...

in 1973. He was also an Air Force Lieutenant at

Wright-Patterson Air Force Base Wright-Patterson Air Force Base (WPAFB) is a United States Air Force base and census-designated place just east of Dayton, Ohio, in Greene County, Ohio, Greene and Montgomery County, Ohio, Montgomery counties. It includes both Wright and Patte ...

(WP-AFB), where he began professional work in 1971. He became Deputy Director of the Energy Conversion Lab at WP-AFB, managed by jet inventor

Hans von Ohain Hans Joachim Pabst von Ohain (14 December 191113 March 1998) was a German physicist, engineer, and the designer of the first operational jet engine. Together with Frank Whittle he is called the "father of the jet engine". His first test unit ran ...

. In 1975, Paul left the

Air Force An air force – in the broadest sense – is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an a ...

to be a Manager of Advanced Programs at

Rockwell International Rockwell International was a major American manufacturing conglomerate involved in aircraft, the space industry, defense and commercial electronics, components in the automotive industry, printing presses, avionics and industrial products. R ...

's Navy Aircraft Plant. In 1985, he was appointed Chief Aeronautical Scientist at Lockheed, trying to come up with a new line of business.

inspired Bevilaqua to think like an engineer rather than a mathematician - "in school I learned how to move the pieces, and Hans taught me how to play chess", although he said that about Purdue as well. Ohain also showed Bevilaqua "what those TS-diagrams actually mean". While at WP, Ohain, Bevilaqua and others investigated and patented various flow related concepts, some of them flow multipliers related to

vertical take-off and landing A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-win ...

Invention of LiftFan

In the 1980s, the

United States Marine Corps The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combi ...

wanted a Vertical/Short Takeoff and Landing (V/STOVL)

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

with more

speed In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quanti ...

and

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

than the Harrier/

AV-8B The McDonnell Douglas (now Boeing) AV-8B Harrier II is a single-engine ground-attack aircraft that constitutes the second generation of the Harrier family, capable of vertical or short takeoff and landing (V/STOL). The aircraft is primaril ...

. Bevilaqua was working for Lockheed Skunk Works in 1986, when

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adv ...

and the similar British agency launched a program called ASTOVL and issued a 9-month contract to develop concepts for a stealthy

supersonic Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...

STOVL A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway). The ...

plane, in accordance with

USMC The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through co ...

wishes, but without the usual strict technical requirements. The challenge in combining supersonic flight and STOVL is that an engine powerful enough to

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobile ...

an aircraft would be too wide to be supersonic, as shown by the Harrier. A smaller engine with higher air flow was needed, but seemed impossible.
Inspired by the

General Electric CJ805 The General Electric CJ805 is a jet engine which was developed by GE Aviation in the late 1950s. It was a civilian version of the General Electric J79, J79 and differed only in detail. It was developed in two versions. The basic CJ805-3 was a t ...

-23 aft-turbofan and the

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...

tandem-fan, an appropriate system seemed to be a dual thrust system with a lift vector at the front and a swivel nozzle at the back for the jet engine, counterbalancing each other.
Many options were investigated. With one month left and no results, Bevilagua took another look at the situation. Three elements were clear: * a turbine is the best way of extracting power from a jet * a shaft is the best way of transferring that power forward * a fan is the best way of converting power to thrust or lift Exploiting bypass air is the usual way of increasing thrust, but when air flow drops so does pressure, which increases engine speed at the risk of failure. This apparent flaw suddenly turned to a benefit when it dawned upon him that the extra engine power could be put to good use by turning a lift fan. "It took eight months of brainstorming to program the computer in my head, and ten seconds to come up with the idea."
The solution involved transforming some of the jet blast to vertical air flow by extracting energy from the hot jet blast with a turbine that turns a shaft driving a fan pointing down, thereby increasing

impulse Impulse or Impulsive may refer to: Science * Impulse (physics), in mechanics, the change of momentum of an object; the integral of a force with respect to time * Impulse noise (disambiguation) * Specific impulse, the change in momentum per uni ...

and thus lift, without increasing drag. The transition between horizontal and vertical lift needs to be precisely controlled, and the two lift columns need to be carefully balanced, to maintain control of the aircraft. The system works similarly to a

turbofan The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which ac ...

, with an extra bypass fan moved and tilted 90 degrees to move cool unburned air vertically instead of horizontally, or a turbine helicopter whose

rotor Rotor may refer to: Science and technology Engineering *Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator * Helicopter rotor, the rotary wing(s) of a rotorcraft ...

is shrunk and encased. This effect is similar to the previous flow multiplier concepts investigated by Bevilaqua (see #List of Papers) and others (although methods are different), achieving a lift/thrust-ratio of 1.5:1 where previous successful aircraft were limited to 1:1 at best. Bevilaqua is not a

propulsion Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...

engineer, and got help from various Lockheed experts in propulsion, materials, and other specialized fields to verify the theories of the concept, which were then patented in 1990-93. Both DARPA and the Marine Corps approved of the concept, and from there, it developed through various defense programs such as CALF and JAST into the

Joint Strike Fighter Program Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Italy, Canada, Australia, the Netherlands ...

and through to the X-35B and F-35B. Bevilaqua was a key figure in persuading the Air Force in 1992 that the concept aircraft could be useful as a conventional aircraft without the

LiftFan The Rolls-Royce LiftSystem, together with the F135 engine, is an aircraft propulsion system designed for use in the STOVL variant of the F-35 Lightning II. The complete system, known as the Integrated Lift Fan Propulsion System (ILFPS), was a ...

. When the

US Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of ...

also came on board, the road was paved for the JSF concept of similar aircraft with different applications, in accordance with JAST Concept Exploration findings. The practical development and testing of the F135 engine and system was performed by

Pratt & Whitney Pratt & Whitney is an American aerospace manufacturer with global service operations. It is a subsidiary of Raytheon Technologies. Pratt & Whitney's aircraft engines are widely used in both civil aviation (especially airlines) and military aviat ...

Allison Engine Company The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James A. Allison, James Allison in 1929 the company was purchased by the Fisher Body, Fisher brothers. Fisher sold the company to General Motors, ...

,-as Allison begins JSF lift-fan tests
''Flight International'', 21 May 1997. Retrieved: 19 September 2010. .

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

,Lam, David W.
Lift Fan nozzle for JSF tested in NASA Lewis' Powered Lift Rig
''

'', 15 April 1998. Retrieved: 18 September 2010. Rolls-Royce and others. One of the key factors in handing the $200B JSF contract to LM is said to be when the X-35B took off from 150feet of runway, went supersonic, and landed vertically in one flight on July 20, 2001 - a performance that only the X-35B had done, and only because of the LiftFan concept. The JSF team was awarded the

Collier Trophy The Robert J. Collier Trophy is an annual aviation award administered by the U.S. National Aeronautic Association (NAA), presented to those who have made "the greatest achievement in aeronautics or astronautics in America, with respect to im ...

2001 for the working system, and Bevilaqua received the Paul E. Haueter Memorial Award ( American Helicopter Society) in 2004.Paul E. Haueter Award
, '' American Helicopter Society''

List of Papers

:: Paul M. Bevilaqua "Evaluation of Hypermixing for Thrust Augmenting Ejectors," Journal of Aircraft, Vol. 11, No. 6, June1974, pp. 348–354 :: Paul M. Bevilaqua, "Analytic Description of Hypermixing and Test of an Improved Nozzle," Journal of Aircraft, Vol. 13, No. 1, January 1976, pp. 43–48 :: Paul M. Bevilaqua, "Lifting Surface Theory for Thrust-Augmenting Ejectors," AIAA Journal, Vol. 16, No. 5, May 1978,pp. 475–581). :: Paul M. Bevilaqua and Paul S. Lykoudi
"Turbulence memory in self-preserving wakes"
Journal of Fluid Mechanics, Volume 89, Issue 03, December 1978, pp 589–606 :: Paul M. Bevilaqua, Howard L. Toms J
"A Comparison Test of the Hypermixing Nozzle."
:: Paul M. Bevilaqua, John D. Lee
"Development of a Nozzle to Improve the Turning of Supersonic Coanda Jets" (1980)
:: Paul M. Bevilaqu
One-page Preview of "Joint Strike Fighter Dual-Cycle Propulsion System"
Journal of Propulsion and Power, 2005, vol. 21, no5, pp. 778–783

References

External links

* Paul Bevilaqua
The shaft driven Lift Fan propulsion system for the Joint Strike Fighter
Presented May 1, 1997. DTIC.MIL Word document, 5.5 MB

{{DEFAULTSORT:Bevilaqua, Paul 1945 births American aerospace engineers Living people Collier Trophy recipients Members of the United States National Academy of Engineering Purdue University School of Aeronautics and Astronautics alumni