Go Back  PPRuNe Forums > PPRuNe Social > Jet Blast
Reload this Page >

This one was shifting it

Jet Blast Topics that don't fit the other forums. Rules of Engagement apply.

This one was shifting it

Old 6th May 2013, 05:12
  #1 (permalink)  
Thread Starter
 
Join Date: Apr 2006
Location: On the Bay, Vic, Oz
Age: 75
Posts: 416
This one was shifting it

The sleek, missile-shaped WaveRider was released from a B-52 bomber 50,000 feet above the Pacific and was initially accelerated by a rocket before the scramjet kicked in.

It reached Mach 4.8 in less than half a minute powered by a solid rocket booster. After separating from the booster, the scramjet engine was ignited, accelerating the aircraft to Mach 5.1 at 60,000 feet.

The flight ended with a planned plunge into the ocean. The WaveRider traveled more than 370 kilometres in six minutes, making it the longest hypersonic flight of its kind. Engineers gathered data before it splashed down.

Experimental hypersonic aircraft hits 4828 km/h


US Air Force illustration shows the X-51A Waverider set to demonstrate hypersonic flight. Photo: AFP Photo/US Air Force
alisoncc is offline  
Old 6th May 2013, 05:21
  #2 (permalink)  
 
Join Date: Feb 1998
Location: Formerly of Nam
Posts: 1,595
50,000ft? I didn't know B52s could reach that high.
Slasher is offline  
Old 6th May 2013, 05:23
  #3 (permalink)  
Thread Starter
 
Join Date: Apr 2006
Location: On the Bay, Vic, Oz
Age: 75
Posts: 416
They don't. They lowered the Pacific just to make it look good.
alisoncc is offline  
Old 6th May 2013, 05:34
  #4 (permalink)  
Psychophysiological entity
 
Join Date: Jun 2001
Location: Tweet Rob_Benham Famous author. Well, slightly famous.
Age: 79
Posts: 4,630
The Rivetess explains why a B52 can go as high as it bloodywell wants.


Loose rivets is offline  
Old 6th May 2013, 06:49
  #5 (permalink)  
Paid...Persona Grata
 
Join Date: Aug 2004
Location: Between BHX and EMA
Age: 73
Posts: 235
Exciting ride for a pilot or pax - 5g according to my rough calcs. Can't imagine what it would be like, I've only experienced 3g for the duration of a loop and 2g for a few minutes.
UniFoxOs is online now  
Old 6th May 2013, 07:51
  #6 (permalink)  
 
Join Date: Dec 2000
Location: Naughty step
Posts: 1,110
So, who was the naughty fellow who loosed off a missile near the western seaboard of France, yesterday? Someone asking ATC if they had anything on radar since a contrail was seen to go vertically up to "about 40,000 feet" and then down again.

A few tense moments in the flightdeck, methinks.
blue up is offline  
Old 6th May 2013, 07:55
  #7 (permalink)  
 
Join Date: Jan 2008
Location: Australia - South of where I'd like to be !
Age: 54
Posts: 4,245
The French did.

It's on line, search for French missile test Western France.

It was a sub launched ICBM that failed.
500N is offline  
Old 6th May 2013, 09:23
  #8 (permalink)  
 
Join Date: May 2009
Location: Confoederatio Helvetica
Age: 64
Posts: 2,847
Wonder what the purpose of all this is. Could anyone live through an acceleration to Mach 5 in less than a minute?

No, my vote is for the Solar Impulse - 0 to Mach 0.01 in a couple of hours, but who's counting.
ExXB is offline  
Old 6th May 2013, 10:18
  #9 (permalink)  
Thread Starter
 
Join Date: Apr 2006
Location: On the Bay, Vic, Oz
Age: 75
Posts: 416
Wonder what the purpose of all this is. Could anyone live through an acceleration to Mach 5 in less than a minute?
We can get you from LHR to JFK in 90 minutes, but you will look like a pile of raspberry jelly when you get there.
alisoncc is offline  
Old 6th May 2013, 13:13
  #10 (permalink)  
 
Join Date: Sep 2001
Location: 38N
Posts: 356
NEW NICHE FOR FEDEX, EH?
arcniz is offline  
Old 6th May 2013, 17:25
  #11 (permalink)  
 
Join Date: Oct 2010
Location: UK
Posts: 238
Only view in reflection on your shield!

We can get you from LHR to JFK in 90 minutes
Shame about the 120 min. hold at JFK!

Mach 4.8 in less than half a minute
Permanent rictus grin - this was the sole passenger at the post launch ball...


Last edited by rmcb; 6th May 2013 at 17:38. Reason: Added mugshot
rmcb is offline  
Old 6th May 2013, 17:45
  #12 (permalink)  
PTT
 
Join Date: Nov 2000
Posts: 441
Wonder what the purpose of all this is. Could anyone live through an acceleration to Mach 5 in less than a minute?
The quote states less than half a minute, but:
Mach 5 = 1701.45 m/s
Acceleration from 0 to that speed in, say, 30 secs
a = (vi - vf)/t
a = 1701.45/30
a = 56.715 m/s^2

1g = 9.80665 m/s^2
acceleration = 5.78g

So a constant ~6g acceleration for about 30 secs. Survivable? Maybe, given the correct suit etc.

All that assumes a constant acceleration rather than staged.
PTT is offline  
Old 6th May 2013, 20:30
  #13 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 5,008
So a constant ~6g acceleration for about 30 secs. Survivable?
What would this be like on the average 40 Yo fat passenger with a touch of diarrhea ?
lomapaseo is offline  
Old 6th May 2013, 20:32
  #14 (permalink)  
 
Join Date: Jan 2008
Location: Australia - South of where I'd like to be !
Age: 54
Posts: 4,245
Messy


Don't be a cleaner afterwards !
500N is offline  
Old 6th May 2013, 20:36
  #15 (permalink)  
 
Join Date: Mar 2008
Location: London
Posts: 689
He or she would be fine, but the people sat behind them would be a little worse for wear.
dead_pan is offline  
Old 6th May 2013, 21:06
  #16 (permalink)  
 
Join Date: Nov 2008
Location: Darkest Surrey
Posts: 5,583
We can get you from LHR to JFK in 90 minutes,
However Homeland Security will still take 12 hours to process you and check your luggage.
racedo is online now  
Old 6th May 2013, 23:25
  #17 (permalink)  
 
Join Date: Sep 2002
Location: Great South East, tired and retired
Posts: 2,206
Not accelerating from zero - you are already being carted around in a B52 at Mach .82

And the acceleration is into the back of your seat, quite tolerable. Like the astronauts lying prone as they go vertical, you will be sitting vertical and accelerating laterally.
Ascend Charlie is offline  
Old 7th May 2013, 03:28
  #18 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 831
They finally got one to fly without a failure, good on them. They were contenders for the Collier Trophy in 2010 but lost to the Sikorsky X2.

The acceleration of the waverider under rocket power has little to do with the final application. It was an easy way to get it going fast enough for the scramjet to work. Some years down the road if they fly people the aircraft will be big enough to hold lots of fuel, probably conventional engines too, for the purpose of getting fast enough for the scramjet to work as well as providing the necessary range and endurance.

The solid booster did most of the work and the scramjet took it from Mach 4.8 to Mach 5.1, though they hoped for Mach 6. The magic is that an air breathing engine achieved Mach 5.1. That is speedy.

Bryan

Last edited by IFMU; 7th May 2013 at 03:32.
IFMU is offline  
Old 7th May 2013, 03:54
  #19 (permalink)  
 
Join Date: Jan 2008
Location: Australia - South of where I'd like to be !
Age: 54
Posts: 4,245
IFMU

I agree, it was good to see them get one going at last.

Isn't the first application of this technology high speed missiles
so they can lob anywhere in the world before people have a chance
to escape ?
500N is offline  
Old 7th May 2013, 15:43
  #20 (permalink)  
 
Join Date: Mar 2005
Location: Poplar Grove, IL, USA
Age: 52
Posts: 831
500N,

Yes and no according to the media:

The Air Force said the four X-51As were built to demonstrate the new technology, not as a prototype for a new weapon system. The program is aimed at paving the way to future hypersonic weapons, hypersonic intelligence, surveillance and reconnaissance, and future access to space, it said.
Bryan
IFMU is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.