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Title: Airbreathing Acceleration Toward Earth Orbit

Abstract

As flight speed increases, aerodynamic drag rises more sharply than the availability of atmospheric oxygen. The ratio of oxygen mass flux to dynamic pressure cannot be improved by changing altitude. The maximum possible speed for airbreathing propulsion is limited by the ratio of air capture area to vehicle drag area, approximately Mach 6 at equal areas. Simulation of vehicle acceleration shows that the use of atmospheric oxygen offers a significant potential for minimizing onboard consumables at low speeds. These fundamental calculations indicate that a practical airbreathing launch vehicle would accelerate to near steady-state speed while consuming only onboard fuel, then transition to rocket propulsion. It is suggested that an aircraft carrying a rocket-propelled vehicle to approximately Mach 5 could be a realistic technical goal toward improving access to orbit.

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
910206
Report Number(s):
UCRL-CONF-230882
TRN: US200723%%549
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: Presented at: 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Cincinnati, OH, United States, Jul 08 - Jul 11, 2007
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; ACCELERATION; AERODYNAMICS; AIR; AIRCRAFT; ALTITUDE; AVAILABILITY; OXYGEN; PROPULSION; ROCKETS; SIMULATION; VELOCITY

Citation Formats

Whitehead, J C. Airbreathing Acceleration Toward Earth Orbit. United States: N. p., 2007. Web.
Whitehead, J C. Airbreathing Acceleration Toward Earth Orbit. United States.
Whitehead, J C. Wed . "Airbreathing Acceleration Toward Earth Orbit". United States. doi:. https://www.osti.gov/servlets/purl/910206.
@article{osti_910206,
title = {Airbreathing Acceleration Toward Earth Orbit},
author = {Whitehead, J C},
abstractNote = {As flight speed increases, aerodynamic drag rises more sharply than the availability of atmospheric oxygen. The ratio of oxygen mass flux to dynamic pressure cannot be improved by changing altitude. The maximum possible speed for airbreathing propulsion is limited by the ratio of air capture area to vehicle drag area, approximately Mach 6 at equal areas. Simulation of vehicle acceleration shows that the use of atmospheric oxygen offers a significant potential for minimizing onboard consumables at low speeds. These fundamental calculations indicate that a practical airbreathing launch vehicle would accelerate to near steady-state speed while consuming only onboard fuel, then transition to rocket propulsion. It is suggested that an aircraft carrying a rocket-propelled vehicle to approximately Mach 5 could be a realistic technical goal toward improving access to orbit.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed May 09 00:00:00 EDT 2007},
month = {Wed May 09 00:00:00 EDT 2007}
}

Conference:
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