G.V.R.Rao (Gadicharla V R Rao)
Born24 June 1918
Rajahmundry, Andhra Pradesh, India
Died27 May 2005(2005-05-27) (aged 86)
Thousand Oaks, California, USA
Known forBell nozzle, also commonly called the Rao Nozzle[1]

Gadicharla V.R. Rao (G. V. R. Rao), D.Sc. (June 24, 1918- May 27, 2005) was an American aerospace engineer of Indian origin who worked in the jet engine and rocket propulsion fields.[2] Rao worked for General Electric in their Gas Turbine Division department and was a research scientist at Marquardt Aircraft, before working for Rocketdyne,[2] where he designed the optimum thrust nozzle. Often referred to as the "Rao's nozzle", it is part of the standard design for rocket engines.[3] The Rao Nozzle is used currently in rocket, missile, and satellite control systems worldwide. It is taught in universities that offer Aerospace Engineering, including Massachusetts Institute of Technology (MIT),[4] California Institute of Technology (Caltech),[5] and Georgia Institute of Technology.[1]

During his career, he also worked on aerodynamic and fluid dynamic design projects, such as chemical lasers, the space shuttle main engines[3][6][7] scramjet and aerospike rocket engines, and wind-powered generators.[3]

Personal life and education

On June 24, 1918, Rao was born in Rajahmundry[2][3][8] in the Andhra Pradesh province of southeastern India. His father was a school headmaster. Rao was born into a large Brahmin household,[3] and is related to Gadicherla Harisarvottama Rao, a well-known freedom fighter for India's independence.

Rao attended Madras Engineering College, and then came to the United States, where he received his D.Sc. in Aeronautical Engineering from New York University in 1949.[2]

He met and married Mary Fabrizio in New York, and they subsequently moved to Bangalore, India.[3][8] Rao and Mary returned to America after their first son, Raman was born. Rao then worked at General Electric. Their second son, Krishna was born, and the family subsequently moved to Woodland Hills, California.[3] In 1976, the Raos moved to Thousand Oaks. Rao died at the age of 86 on May 27, 2005.[3]

Career

Nozzles of Saturn-V
Nozzle of an extensible Cryogenic Engine

Educator

After receiving his D.Sc., Rao taught in Bangalore, India at the Graduate Research Institute.[3]

Aerospace engineer

From 1952 to 1955, Rao worked for General Electric in their Gas Turbine Division. He was then a research scientist at Marquardt Aircraft until 1958. Rao then worked for Rocketdyne in California as a design analyst.[2][9]

Beginning in the mid-1950s, Rao began to use mainframe computers at Rocketdyne to make computations for the design of rocket nozzles. Kramer and Wheelock state, "Rao developed a method for determining the nozzle contour that would produce the maximum thrust for any given nozzle area ratio and length... The optimum turned out to be not only more efficient but also considerably shorter by about 60% than a 15-degree conical nozzle of the same area."[10] George P. Sutton, who worked with Rao at Rocketdyne, said that "bell shape or curved exit contour is used almost universally today for nozzles designed since about 1960 for large as well as small thrust chamber nozzles" and for both solid and liquid propellants.[11] In 1963, the Advanced Propulsion Section of NASA published Computation of Plug Nozzle Contours by the Rao Optimum Thrust Method about a study that was performed to design a plug nozzle using Rao's maximum thrust theory using a FORTRAN computer program.[12] In 1983, Rao's design was modified, with a slightly different contour, to maximize performance.[13]

In 1961, Rao worked at National Engineering Science Company as associate director.[2] By 1970, he formed his own company, G. V. R. Rao and Associates, through which he contracted with NASA.[14] He worked at Rockwell International for Marshall Space Flight Center in 1988.[15] During his career, he also worked on aerodynamic and fluid dynamic design projects, such as chemical lasers, the space shuttle main engines[3][6][7] scramjet and aerospike rocket engines, and wind-powered generators.[3]

His patented inventions include Device for thrust spoiling and thrust reversal (1957),[16] Quiet fan with non-radial elements (1975),[17] Shock wave suppressing flow plate for pulsed lasers (1984),[18][19] and Mixing aids for supersonic flows (1990).[19][20]

Publications

  • Rao, G. V. R. (June 1958). "Exhaust Nozzle Contour for Optimum Thrust". Journal of Jet Propulsion. 28 (6): 377–382. doi:10.2514/8.7324.
  • Rao, G. V. R. (August 1958), Contoured Rocket Nozzles. Paper presented at Ninth Annual Cong. Int. Astronautical Federation (Amsterdam)
  • Rao, G. V. R. (May 1960). "Analysis of a New Concept Rocket Nozzle". Liquid Rockets and Propellants. American Institute of Aeronautics and Astronautics. pp. 669–682. doi:10.2514/5.9781600864759.0669.0682. ISBN 978-1-56347-851-2.
  • Rao, G. V. R. (June 1960). "Approximation of Optimum Thrust Nozzle Contour". ARS Journal. 30 (6): 561.
  • Rao, G. V. R. (1961). "Nozzle Contours". Handbook of Astronautical Engineering. New York: McGraw-Hill. Chapter 20.33
  • Rao, G. V. R. (1971). Study of Non-radial Stators for Noise Reduction. National Aeronautics and Space Administration.

References

  1. 1 2 "Bell/Contoured Nozzles" (PDF). GA Tech. Retrieved November 27, 2016.
  2. 1 2 3 4 5 6 G. V. R. RAO (November 1961). "Recent Developments in Rocket Nozzle Configurations" (PDF). ARS Journal. 31 (11): 1488–1494. doi:10.2514/8.5837. Retrieved November 27, 2016.
  3. 1 2 3 4 5 6 7 8 9 10 11 "Gadicherla V R Rao". Ventura Star Newspaper. May 28, 2005. Retrieved November 27, 2016. It was posted soon after his death, the exact date is unclear
  4. ↑ "Types of Nozzles; Connection of flow to nozzle shape. MIT OpenCourseWare: Lecture 8" (PDF). MIT. p. 6. Retrieved July 30, 2016.
  5. ↑ S. R. Kulkarni. "Nozzles". Caltech. p. 8. Retrieved November 27, 2016.
  6. 1 2 Lepore, Frank A. (June 1991). "Flow Induced Vibration in SSME Injection heads" (PDF). Rocketdyne Division, Rockwell International. Retrieved November 27, 2016 – via NASA. {{cite journal}}: Cite journal requires |journal= (help)
  7. 1 2 D.G. Pelaccio; F.F. Lepore; G.M. O'Connor; G.V.R. Rao; G.H. Ratekin; S.T. Vogt (June 1984), Experimental Evaluation of an Advanced Space Shuttle Main Engine Hot Gas Manifold Design Concept, American Institute of Aeronautics and Astronautics (AIAA)
  8. 1 2 Who's who in World Aviation and Astronautics. American Aviation Publications, Inc. 1958. p. 362.
  9. ↑ Missiles and Rockets. American Aviation Publications. January 1958. p. 175.
  10. ↑ Kraemer, Robert S.; Wheelock, Vince (2006). Rocketdyne: Powering Humans Into Space. AIAA. p. 83. ISBN 978-1-56347-754-6.
  11. ↑ Sutton, George Paul (2006). History of Liquid Propellant Rocket Engines. AIAA. p. 92. ISBN 978-1-56347-649-5.
  12. ↑ "Computation of Plug Nozzle Contours by the Rao Optimum Thrust Method. NASA Technical Document". July 1, 1963. Retrieved November 27, 2016.
  13. ↑ J. L, Tuttle; D. H. Blount (May 1983). "Perfect Bell Nozzle Parametric and Optimization Curves - NASA Reference Publication 1104" (PDF). NASA: 7–8. Retrieved July 30, 2016. {{cite journal}}: Cite journal requires |journal= (help)
  14. ↑ "G.+V.+R.+"+OR+"G.V.R."+Rao NASA Tech Brief. NASA. 1970.
  15. ↑ Tech Notes. U.S. Department of Commerce, National Technical Information Service, Center for the Utilization of Federal Technology. 1988. p. 26.
  16. ↑ "Device for thrust spoiling and thrust reversal - US Patent 2,791,088 A". May 7, 1957. Archived from the original on August 11, 2014.
  17. ↑ "Quiet fan with non-radial elements - United States Patent: 3,883,264". United States Patent and Trademark Office. May 13, 1975. Retrieved November 27, 2016.
  18. ↑ "Shock wave suppressing flow plate for pulsed laser - US patent: 4,457,000". United States Patent and Trademark Office. June 1984. Retrieved November 27, 2016.
  19. 1 2 "Patents by Inventor Gadicherla V. R. Rao". Justia. Retrieved November 27, 2016.
  20. ↑ "Mixing aids for supersonic flows - United States Patent 4,899,772". United States Patent and Trademark Office. February 13, 1990. Retrieved November 27, 2016.

Further reading

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