HyFly - hypersonic missile
program with hydrocarbon fuel - DARPA, ONR, Johns
Hopkins APL, Boeing, Aerojet and NASA
Uses a dual combustion approach. Air enters
one point and in ramjet fashion is slowed to subsonic
speeds and ignited. Supersonic air travels through
a second port and mixes with the combustion products
from the other chamber and completes the burning.
This approach overcomes the drop in thrust in
normal ramjets at around Mach 5. The HyFly technology
is intended only for one-time use, i.e. missiles
HyTech - hypersonic
missile program with hydrocarbon fuel - Air Force,
NASA, Pratt & Whitney
Usually only hydrogen is considered as a fuel
for scramjets due to the brief time available
for combustion (~1millisec). This program, however,
uses conventional jet fuel (e.g. JP7) but uses
the heat generated in the walls of the combustion
chamber to "crack" the fuel into lighter
and more volatile elements that will enter the
supersonic flow and burn quickly enough to generate
positive thrust at Mach 6 and higher. The program
seeks to provide engine technology useful to
both missiles and reusable vehicles.
test of a scramjet engine launched on a missile
"Holo" - GLL "Cold" , also called
"Holo" (hypersonic flying laboratory).
- similar to Hyper-X 43A for scramjet research.
FIrst flight in 1991 and seven by 1999. Contract
in 1998 with NASA. Scramjet runtime up to 77sec.
and reached 6.49 Mach.
Future Flight Test Plans of an Axisymmetric
Hydrogen-Fueld Scramjet Engine on the Hypersonic
Flying Laboratory (pdf, 333kb), Roudakov et
al, 7th International Spaceplanes and Hypersonics
Systems & Technology Conference November 18–22,
CIAM/NASA Mach 6.5 Scramjet Flight and Ground
Test, R. T. Voland et al, AIAA-99-4848, 1999
- "...while the flow entering the fuel/air
mixing zone at the first ac injector station was
supersonic (M ~ 2), combustion forced the Mach
number to a subsonic value before reaccelerating
the flow to sonic velocity at the combustor exit."
(Integrated System Test of an Airbreathing Rocket)
at MSFC - "ISTAR is a rocket-based combined-cycle
engine that employs a hydrocarbon-powered liquid
rocket system for initial acceleration, with a
ramjet that ignites at about Mach 2.5, followed
by a conversion to scramjet at around Mach 5.
It is to accelerate to Mach 7" on the X-43B.
- Craig Covault/Aviation Week