Optimisation of scramjet-assisted access-to-space vehicles using oxygen enrichment

Razzaqi, Sarah A., Jazra, Thomas, Smart, Michael K. and Ferguson, Thomas (2011). Optimisation of scramjet-assisted access-to-space vehicles using oxygen enrichment. In: Wayne Short and Iver Cairns, Proceedings of the 10th Australian Space Science Conference. 10th Australian Space Science Conference (ASSC), Brisbane, Australia, (67-78). 27-30 September 2010.

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Name Description MIMEType Size Downloads
Author Razzaqi, Sarah A.
Jazra, Thomas
Smart, Michael K.
Ferguson, Thomas
Title of paper Optimisation of scramjet-assisted access-to-space vehicles using oxygen enrichment
Conference name 10th Australian Space Science Conference (ASSC)
Conference location Brisbane, Australia
Conference dates 27-30 September 2010
Proceedings title Proceedings of the 10th Australian Space Science Conference
Journal name Australian Space Science Conference Series
Place of Publication Sydney, Australia
Publisher National Space Society of Australia
Publication Year 2011
Sub-type Fully published paper
Open Access Status
ISBN 9780977574049
Editor Wayne Short
Iver Cairns
Start page 67
End page 78
Total pages 12
Collection year 2012
Language eng
Formatted Abstract/Summary
The option of scramjet-assisted access to space is a key focus at The University of Queensland’s Centre for Hypersonics. A three-stage, rocket-scramjet-rocket configuration is envisaged for fulfilment of this task, in which the flight envelope of the airbreathing second stage dictates the performance requirements of the complementary rocket stages. The payload mass fraction of the launch vehicle is strongly coupled with the performance of the airbreather. The present paper investigates oxygen enrichment as an option to extend the flight envelope of the second stage and thus increase the efficiency of the launch vehicle. Three Mach 12 REST scramjets are integrated with the airframe of a NASA winged-cone vehicle to assemble the second vehicle stage. Using multidisciplinary optimisation of this airbreather, the effect on the design and performance of the vehicle from supplementing the freestream oxygen flow by 10% and 20%, through the premixng of oxygen with fuel, is analysed. As suggested by a related study, the freestream dynamic pressure is held constant at q = 100 kPa during the ascent of the airbreather. It is shown that within the current vehicle model, oxygen enrichment increases the final Mach number and altitude of the second stage airbreather, which results in a larger absolute payload mass. However, the masses of airbreather and first stage rocket are also greater for the vehicles using oxygen enrichment. As a result, the payload mass fraction is only marginally different to the baseline non-enriched vehicle. The current model is, however, limiting in several respects, including the assumption of a constant onboard oxygen mass and the coupling of critical optimisation parameters. With refinement of the model, it is plausible that oxygen enrichment can be used to further improve vehicle performance.
Q-Index Code E1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Distributed on DVD.

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Created: Fri, 17 Jun 2011, 09:14:19 EST by Ms Sarah Razzaqi on behalf of School of Mechanical and Mining Engineering