NASA STTR 2004 Solicitation


RESEARCH SUBTOPIC TITLE:Advanced Concepts for Flight Research
PROPOSAL TITLE:Optimal Thrust Vectoring for an Annular Aerospike Nozzle

NAME: Rolling Hills Research Corporation NAME:California Polytechnic State University Foundation
ADDRESS:420 N. Nash Street ADDRESS:1 Grand Avenue
CITY:El Segundo CITY:San Luis Obispo
STATE/ZIP:CA  90245-2822 STATE/ZIP:CA  93410-0001
PHONE: (310) 640-8781 PHONE: (805) 489-0237

Thomas W. Carpenter

TECHNICAL ABSTRACT ( Limit 2000 characters, approximately 200 words)
Recent success of an annular aerospike flight test by NASA Dryden has prompted keen interest in providing thrust vector capability to the annular aerospike nozzle (AAN). The AAN with a moveable spike for thrust vectoring and throttling could provide a more efficient alternative to traditional bell nozzles.

Cal Poly, which has a thrust vector research facility, has teamed with Rolling Hills Research Corporation, with CFD capability, to experimentally and analytically determine the optimal approach to thrust vectoring and throttling the AAN.

In Phase I, several scale AAN models were fabricated with movable spikes that could be displaced and/or gimballed. One set of studies quantified thrust changes as a function of spike axial position for throttling. Other studies examined the thrust vectoring effectiveness of various proprietary nozzle configurations. Schlieren photography and 3-axis force measurements showed excellent correlation to predictions made with the OVERFLOW CFD code.

The most promising of the nozzle configurations for thrust vectoring and throttling were shown to produce stable flow that generates a resultant turn angle whose magnitude is in the neighborhood of current rocket booster technology. These promising configurations have been selected for extensive laboratory testing and computational analysis for optimization in the Phase II program. The objective of Phase III will be flight test.

POTENTIAL NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
In the near term, aerospike nozzles with optimal thrust vector control will provide added safety and improved capability to the NASA Dryden Aerospike Rocket Test project, as well as economic benefit through the reuse of nozzles. Thrust vectoring and throttling capabilities would provide control of flight regimes (speed, angle of incidence, transients, and other flight conditions). In addition, flights with thrust vector control would have less dispersion and therefore could be confined to a smaller test area, which would improve range safety.

An aerospike nozzle with thrust vector control would be appropriate for future NASA single-stage-to-orbit programs.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
Now, in the early 21st century, we stand at the threshold of affordable commercial access to space. In the future, single-stage-to-orbit (SSTO) reusable launch vehicles (RLV) will provide relatively inexpensive (less than $5M) and widespread commercial access to space. Due to their inherent altitude compensation, aerospike rocket nozzles are ideal for SSTO vehicles. A self-contained aerospike nozzle with thrust vectoring and throttling capability would provide a practical, cost-effective means of controlling the rocket flight path for such vehicles.

Commercial applications for relatively inexpensive SSTO RLVs are virtually unlimited, but certainly include the economically significant small satellite launch business.

Form Printed on 01-27-06 14:58