1999 NASA STTR Phase-I Proposal
Proposal #: 990103 

1. Research Topic:     04 - Turbomachinery 
2. Project Title:      Technology For Exo-Skeletal Engine Concept 

3. Small Business Concern                        4. Principal Investigator 
   Name:    Alpha STAR Corporation                  Barry Brown 
   Address: 5150 E.PCH No. 500 
   City:    Long Beach 
   ST:      CA Zip:9 

5. Research Institution 
   Name:    Clarkson University 
   Address: Division of Research 
   City:    Postdam 
   ST:      Ny Zip:13699 

6. Technical Abstract (Limit 200 words) 
Effort is proposed to evaluate the feasibility of providing reliable and durable 
rotor drums, fan blade attachments, and high speed bearings for NASA Exo-keletal 
engine concept. High speed bearings are needed to hold the rapidly rotating, 
large diameter, thin walled rotor drun in position within a backbone case. Rotor 
drum evaluations will consider configurations and the use of bearings 
interfacing the backbone case and rotor drum. Fiber reinforced composite 
materials will be considered because their high stiffness will resist fatigue 
from flexure and allow integral fastening of fan blades. Bearings will be 
evaluated relative to high speed wear, friction, rolling resitance, placement, 
size, race configuration, lubrication, heat build-up, and heat dissipation. 
Ball, roller, magnetic, air, and oil bearings will be considered along with the 
use of graphic, carbon-carbon, steel, and cobalt alloys. Computer simulations 
will be made to predict reliability and durability of rotor drums, blade 
attachments, and bearing concepts. Requirements (temperature and loads, 
lubrication, wear resistance, durability, and reliability) to be met will be 
based on engines with 30,000 and 80,000 lbs thursts. Test procedures will be 
outlined to experimentally demonstrate the feasibility of bearing, rotor drum, 
and fan blade attachment approaches for the Exo-Skeletal engine concept. 

7. Potential Commercial Application(s)(Limit 200 words) 
An Exo-Skeletal turbine engine is potentially superior to existing tur-bine 
engines for transport aircraft applications because of increased safety, weight 
reduction by a factor of three, and potential for development as a combined 
turbine-rocket engine. The weight advantage will allow significant increases in 
fuel efficiencies, payload capacities, and flight ranges of aircraft, benefits 
which are highly sought by commercial airlines as well as by the Air Force. 
Thus, the commercial use of an exo-skeletal engine is virutally guranteed once 
developed and demonstrated to be durable and reliable as current turbine engines 
for aircraft use.  Additionally, successful exo-skeletal engine bearing 
technology development could conceivably find application in other areas such as 
engines for supersonic, hypersonic, single-stage-to-orbit space vehicles, high 
rotational speed fly wheels for energy storage, and high speed train engines in 
which bearings are used to hold high rotational speed members accurately in 
position. Also, a scaled down version of successful exo-skeletal bearing 
technology could be applicable to high speed rotating consumer products such as 
CD and DVD compact disk drives, and computer hard disk drives.