ABC Catalyst Episode 20th June 2013 - Scramspace I

shockonlip said:
Inspiring!
I wish them luck!!
Thanks DSE!
Click to expand...

The key question I think is is the inlet going to start? Quite high contraction and totally axisymmetric with no type of spillage starting mechanism. Just looking down the front is down right scary, imo.
 
DSE said:
shockonlip said:
Inspiring!
I wish them luck!!
Thanks DSE!
Click to expand...

The key question I think is is the inlet going to start? Quite high contraction and totally axisymmetric with no type of spillage starting mechanism. Just looking down the front is down right scary, imo.
Click to expand...

It seems there may be spillage starting mechanism.

In: AIAA 2011-2277 - "The SCRAMSPACE I Hypersonic Flight Experiment Feasibility Experiment"
on pg 3, it indicates that at the beginning of re-entry, at low Reynolds No. the boundary layer on
internal engine surfaces is very thick, and the scramjet will be unstarted, so during descent, an
inlet starting door will be open till when when the Reynolds Number gets large enough for
the inlet to remain started.

Even though this paper is several years old, it seems like the door should still be there.
Although other SCRAMSPACE papers reference novel axisymmetric inlet starting techniques
possibly being deployed.

The inlet seems very sensitive to unstart:
- Inlet started angle of attack seems very tight (within +/- 2 deg).
- And simulations on the inlet, unstarted, depending on what turbulence model was used.
(AIAA 2011-2367 - Numerical Simulation of SCRAMSPACE I Flight Experiment).

Also SCRAMSPACE I measures the reduction in drag as H2 fuel is pulsed on/off as the vehicle
descends from 32km to 27km altitude. In other words the external shape of the vehicle has not
been designed to generate a net thrust, therefore the vehicle is expected to produce a net drag.
Therefore the goal of measuring the change in drag as H2 fuel is pulsed on and off (also measuring
pressure and heat flux through the inlet and combustion chamber).
 
Yes, appears I stand corrected in regard to the starting mechanism.

Starting Processes of High Contraction Ratio Scramjet Inlets Report
by G Paniagua - 2012
Jan 23, 2012 - A scaled 2D representation of the SCRAMSPACE-I geometry was constructed, with two ... Successful inlet starting was achieved at conditions.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCwQFjAA&url=http%3A%2F%2Fwww.dtic.mil%2Fcgi-bin%2FGetTRDoc%3FAD%3DADA555033&ei=DNneUbK9LMjZrAHLn4DADA&usg=AFQjCNFj8ldSxcTKMTtooO_7XUcDV4Guog&bvm=bv.48705608,d.aWM
 
http://www.uq.edu.au/news/index.html?article=26722

Unfortunately, not good news:

Australia's SCRAMSPACE hypersonic flight experiment from the Andøya Rocket Range in Norway has been discontinued, following an unsuccessful launch.

The team can confirm the launch took place and both the first and the second stages of the launch have landed safely in the water.

However it appears at this stage that the payload did not reach the correct conditions to begin collecting data as planned.
 

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