RE: 90-degrees of lock at 500mph | Bloodhound LSR

RE: 90-degrees of lock at 500mph | Bloodhound LSR

Sunday 17th November

Bloodhound concludes testing with 1,010km/h run

LSR team completes four-weeks of high-speed testing in style



The Bloodhound LSR team has concluded testing in the Kalahari Desert with a new top speed. Targeting in excess of 600mph, with 'Run Profile 8', the car managed 628mph - or 1,010km/h - after 50 seconds before And Green brought it safely to a half at the 11km mark.

The team has reached incrementally faster speeds over the past four weeks (see below), collecting crucial data on Bloodhound's performance - particularly as it relates to drag. During the final run the analysis showed that airflow beneath the car had gone supersonic and stripped paint from an area three meters back from the front wheels.

It is precisely this kind of lesson which will inform the size of the rocket that must be added to Bloodhound in order for it to achieve a new land speed record in 12-18 months time. Said rocket will delivered by Nammo, a Norwegian specialist, and is expected to produce an additional 60kN of thrust.

Speaking after the final test, Andy Green said: Andy Green added: "This morning we had the perfect conditions for a high speed run; cool temperatures and virtually no wind. After a slick start procedure from the team, the car handled superbly once again.

"The stability and confidence the car gives me as a driver is testament to the years of world class engineering that has been invested in her by team members past and present. With all the data generated by reaching 628 mph [1,010 km/h], we're in a great position to focus on setting a new world land speed record in the next year or so."


Update - 13.11.2019

You might have seen our interview from last week with Andy Green (if not, scroll down), current land-speed record holder and pilot of Bloodhound LSR. In it Green discusses exactly what it feels like to drive the jet-powered juggernaut, explains how he responded to a potential emergency at 480mph, and reveals that despite Bloodhound being an enormous leap on from Thrust SSC, he’s still found himself steering on the lock stops at up to 500mph.

Now, thanks to a newly released video, you can get a better understanding of exactly how Green keeps Bloodhound under his control even in such high pressure circumstances. Showing us around what he dubs his β€œsupersonic office”, he explains where and why each control is placed, and gives a fascinating insight into the thinking behind the layout. We’ll leave it to him to elaborate, but needless to say, next time you see the white and orange machine streaking across the desert surface, you’ll have a much better idea of just what the man risking it all to chase history once again is going through within. Check out the video below!


90-degrees of lock at 500mph - 09.11.2019

Since we last checked in with Bloodhound's testing programme the car has reached some significant milestones - and having recovered from minor damage to hit the 500mph mark on Wednesday, everything seemed to be going fairly smoothly for the team. However, today's attempt at reaching 550mph had to be aborted short of achieving the goal; a setback to the casual observer, but not to Andy Green, whose previous record-breaking experience has taught him to take such things in his stride.

"This is all part of the process," he tells PH when we speak to him from the Hakskeen Pan soon after the conclusion of the test. "The jet started really nicely, it was crisp off the line with very little cross-wind and the car was running beautifully straight. I got up to a little over 450mph and then got a flickering overheat light for the jet engine bay. It's the second time we've had this problem this week, so I throttled back.

"We'd also done a minor modification on the parachute last night; I just analysed the video and that appears to have worked perfectly which is really good. And the other thing I wanted to get out of this run was just to establish what the grip rate is on the desert, because it's a very low-grip surface so we're still working out how quickly we can slow the car down. I pretty much nailed that; I got to exactly after I could feel the wheels starting to slip, which is perfect. So we didn't get to peak speed by a little bit, there's some work to investigate the overly-hot engine bay, but everything else went really well, so personally I'm really pleased with that run."

Those who've seen a Red Arrows display in person, and heard the steady calm of Red One's voice through the PA system as he twists and turns a few thousand feet above, will have some understanding of the composure with which Green recalls the run. The ex-RAF pilot and current land-speed record holder is seemingly unflappable - but how did he react to receiving a warning light at more than twice the top speed ever recorded during an F1 race?


"In my recollection of the run, the caption came on, I looked at the speed, looked at the caption, made a decision that, 'alright, we're going to have to abandon this run' and started throttling back. I paused, and then because we wanted to test the chute at a high speed, throttled back at about 475-480 and then put the chute out within a couple of seconds as the car slowed down through 450. Having watched the video, all of that decision making happened in less than a second, simply because I've considered 'if that happens then I'll do this' so it actually happens in real time much faster than I remember it looking back at it."

This isn't the first challenge the team has faced since they arrived in South Africa last month, and it surely won't be the last. That's not necessarily a bad thing, though; while going fast is all well and good, identifying and overcoming such obstacles will likely be a bigger priority for now, allowing Bloodhound to hit the even greater speeds they're aiming for next year.

"[Earlier in the testing programme] we had an aborted run because there were no anti-bounce software on the switches in the cockpit, we had a switch bounce of less than ten milliseconds and the jet engine shut down. We've now got some anti-bounce software which is what normal road cars have fitted as standard, we simply didn't have it fitted to the car because we didn't know we were going to need it. And this is what high-speed testing is about, this is exactly why we're here. So the fact that we've had a minor overheat is part of understanding what the airflow is like because it's so complex and such a complex shape in the engine bay that, even if you did a full computational fluid dynamics assessment of what the flow is going to be like in there, you'd probably finish up with at best a rough guess and at worst a completely wrong answer.

"So this is one of the things we've got to test, it's a little hotter than we were expecting. The engine bay is able to take very high temperatures but the fire wire goes off at a relatively low temperature [it burns and breaks at 160oC, triggering the alarm] to warn us if something is getting hot in there, which it appears to be. We're going to find out whysome insulation, some more airflow; there are lots of different solutions to this and that of course is part of modifying the car for higher speed running last year, so this is all part of the process."


There's still plenty of work to be done on the car, then. But how does Bloodhound feel to drive compared to Green's previous record-breaker, Thrust SSC?

"It's a lot crisper, a lot more precise. Both cars have very firm suspension but I get a much better feel through this car - for instance, it was impossible to work out where the wheel lock was in Thrust SSC, I got no feeling. I could actually feel it today, to my surprise, which was encouraging. The car is more sensitive to crosswinds than Thrust SSC, but this is not the finished car. We haven't yet added the rocket pack which will move the centre of gravity, reduce the yaw static margin and reduce the crosswind sensitivity. So the aerodynamics are set up for next year's jet and rocket car, for this year's testing the aerodynamics are actually slightly cross-wind sensitive, so there has been up to 90 degrees of steering in the cockpit to try and keep the car straight, and we're running to a relatively 10mph crosswind, but with those limits the car's running really nicely."

That 90-degree figure may have caught your attention, but Green brushes over it as if he's recalling his breakfast order. What does a 90-degree steering input in a land-speed record car actually entail?

"That's two to two-and-a-half degrees at the wheels, the equivalent of putting about 30 or 40 degrees of steering input into a normal road car. Now, 30 or 40 degrees doesn't sound like much, but for example - and please don't try this - if you snapped on 40 degrees of steering at motorway speeds it would really surprise you. It's a lot of steering at high speed, certainly a lot of steering at 400-500mph, but because of the lateral grip of these metal wheels on what is a very slippery surface the steering inputs have to be reasonably rapid, and on occasion reasonably large, in order to keep the car pointing in the direction I want.


"And of course I'm using two different steering techniques: I'm using very rapid inputs for velocity related steering, so to stop the car yawing off line. If it's being pushed sideways by crosswinds, though, we've now got a displacement where physically the car is off line, that has to be a very slow steering correction because you can't just throw a six-tonne car sideways and put it back on line. I'm controlling the direction with very rapid inputs to stop the yaw rate building up in a 13-metre long, six tonne car, and then slowly adjusting the displacement to keep it on line, so it's two different steering inputs depending on what I'm actually trying to do."

From the onboard footage (see below, from 4.40) it's possible to see exactly what he's talking about, the car's path across the desert floor a far less linear one than you might imagine. What's not so apparent from that cockpit camera, however, are the velocities and g-forces which Green is experiencing. With so much to focus on and such flat, featureless surroundings, how great actually is the sense of speed from within the cockpit?

"Enormous. Doing 100mph feels fast, particularly because it only takes a few seconds to get there, and then 200 feels much faster because it only takes a few more seconds to get there. Suddenly, 30 seconds into the run, I'm doing 3-400mph and the ground just keeps coming at me faster and faster and faster and faster. Which is of course the purpose of a land-speed record car, it's unparalleled performance, the highest performance of any racing car in history because it's trying to become the highest performing racing car in history." Bloodhound still has a long way to go to earn that title, though, and the rest of the testing programme will be crucial in getting there. So how soon does the team to expect to be back at it?

"We're taking the opportunity while we're checking the air flow around the engine to do various other jobs. We've got a big long list of engineering tasks, several of which we've said 'well, when we've got a day or two we'll do that' so this weekend is basically going to clear off all of the outstanding jobs fixing minor wiring loom problems and replacing a couple of the pins that hold the engine in place, because they've got to a stage where we want to replace them. There's lots and lots of jobs, so we've got a couple of engineering days now and then we'll be aiming to get the car fighting fit for next week."


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Author
Discussion

Sandpit Steve

Original Poster:

328 posts

21 months

Friday 8th November
quotequote all
Awesome, well done to Andy and the whole Bloodhound team on the huge progress this week.

Truly inspiring after all the setbacks, and they should know that millions of people are following their efforts.

bounceclapwavey

Alias218

899 posts

109 months

Friday 8th November
quotequote all
I think the thing I like most about this weeks runs is the fact that this car was this close to being scrapped and now is making fantastic achievements, seemingly without trying. I think this is testament to all the hard work put in by the various guys and girls that have had a hand in this project in engineering such an outstanding machine, as well as casting all the naysayers to one side. I can’t wait until they strap a rocket to this thing!

Keep up all the good work everyone at Bloodhound LSR HQ and SA!


CrutyRammers

9,551 posts

145 months

Friday 8th November
quotequote all
Picks its skirts up pretty well that, doesn't it?

Pete102

1,089 posts

133 months

Friday 8th November
quotequote all
That 2nd video with the drive by shot is fantastic, I really hope we get more of those types of shots as the speeds are pushed higher.

Otispunkmeyer

9,893 posts

102 months

Friday 8th November
quotequote all
Alias218 said:
I think the thing I like most about this weeks runs is the fact that this car was this close to being scrapped and now is making fantastic achievements, seemingly without trying. I think this is testament to all the hard work put in by the various guys and girls that have had a hand in this project in engineering such an outstanding machine, as well as casting all the naysayers to one side. I can’t wait until they strap a rocket to this thing!

Keep up all the good work everyone at Bloodhound LSR HQ and SA!
Yeah, it all looks very well oiled. It might be the type of surface but I think it looks like butter at 500 mph, barely a concern. Still, its gonna get interesting as they head toward the sound barrier, though one hopes that Thrust SSC having already proven it possible means they'll be well prepared for it.

It did seem though that there might be concern with damage around the rear of the vehicle? On a number of videos they've mentioned having to strip back the body to replace bits that have gotten damaged by the dirt and dust kicked up. I hope its not too serious.... even at 500mph its probably worse than being sand blasted!

Mr.Grooler

928 posts

172 months

Friday 8th November
quotequote all
Excellent news, and great to see it moving in the videos.

deejay005

29 posts

125 months

Saturday 9th November
quotequote all
Amazing.

Andy makes it look so easy at the wheel when it must be absolutely bloody terrifying.

Solid brass kahoonas and no mistake.




wst

3,303 posts

108 months

Saturday 9th November
quotequote all
His description of the steering technique sounds a bit like a description of PID control I heard a few years ago, that's pretty cool.

modeller

329 posts

113 months

Saturday 9th November
quotequote all
Awesome video. Wearing my T shirt bought at FoS a few years back

blearyeyedboy

4,934 posts

126 months

Saturday 9th November
quotequote all
Brilliant news.

Better to find out trouble at 450mph and fix it than to find out at 900mph...

maxdb

1,277 posts

104 months

Saturday 9th November
quotequote all
Awesome work - I love following the progress.

jcl

208 posts

190 months

Saturday 9th November
quotequote all
I’m staggered that they steer these things mechanically and not aerodynamically.

14

1,561 posts

108 months

Saturday 9th November
quotequote all
jcl said:
I’m staggered that they steer these things mechanically and not aerodynamically.
I think it’s because it’s easier to have mechanical steering than aerodynamic steering.

snotrag

11,875 posts

158 months

Saturday 9th November
quotequote all
14 said:
jcl said:
I’m staggered that they steer these things mechanically and not aerodynamically.
I think it’s because it’s easier to have mechanical steering than aerodynamic steering.
I think it's because it's not allowed - it's a 'car' not a plane. A quick Google =

"D2.3.3.b The use of moveable aerodynamic devices is permitted."

FIA land speed record regs.

14

1,561 posts

108 months

Sunday 10th November
quotequote all
snotrag said:
14 said:
jcl said:
I’m staggered that they steer these things mechanically and not aerodynamically.
I think it’s because it’s easier to have mechanical steering than aerodynamic steering.
I think it's because it's not allowed - it's a 'car' not a plane. A quick Google =

"D2.3.3.b The use of moveable aerodynamic devices is permitted."

FIA land speed record regs.
Aerodynamic steering is allowed. From doing a quick google search I found this https://www.bloodhoundeducation.com/land-speed-rec... so it seems the wheels are moving the air around them thus being aerodynamic devices.

geo1905

23 posts

11 months

Sunday 10th November
quotequote all
I've met many brave men and women in my life. I doubt that I've met anyone braver than Andy Green and I probably never will.

Jimbo89

126 posts

91 months

Monday 11th November
quotequote all
Otispunkmeyer said:
Alias218 said:
I think the thing I like most about this weeks runs is the fact that this car was this close to being scrapped and now is making fantastic achievements, seemingly without trying. I think this is testament to all the hard work put in by the various guys and girls that have had a hand in this project in engineering such an outstanding machine, as well as casting all the naysayers to one side. I can’t wait until they strap a rocket to this thing!

Keep up all the good work everyone at Bloodhound LSR HQ and SA!
Yeah, it all looks very well oiled. It might be the type of surface but I think it looks like butter at 500 mph, barely a concern. Still, its gonna get interesting as they head toward the sound barrier, though one hopes that Thrust SSC having already proven it possible means they'll be well prepared for it.

It did seem though that there might be concern with damage around the rear of the vehicle? On a number of videos they've mentioned having to strip back the body to replace bits that have gotten damaged by the dirt and dust kicked up. I hope its not too serious.... even at 500mph its probably worse than being sand blasted!
This is my concern as well, that surface just looks too soft to my untrained eye. I work with sandblasting and I've seen the damage we can do with tiny particles travelling at roughly 300mph. At 1000mph I'm worried the debris and grit they are kicking up will tear the thing apart!

ArmouredBiscuit

1,117 posts

181 months

Monday 11th November
quotequote all
deejay005 said:
Amazing.

Andy makes it look so easy at the wheel when it must be absolutely bloody terrifying.

Solid brass kahoonas and no mistake.
Indeed.....he talks over the radio like he's on a Sunday afternoon sightseeing tour bus, not doing 500mph with his arse inches from the ground and jet engine behind his head.

100% OG.

NFC 85 Vette

2,547 posts

183 months

Monday 11th November
quotequote all
14 said:
Aerodynamic steering is allowed. From doing a quick google search I found this https://www.bloodhoundeducation.com/land-speed-rec... so it seems the wheels are moving the air around them thus being aerodynamic devices.
It's quite an odd sensation, and goes against everything you ordinarily do when steering a car at speed. My old Fiat racecar had a trait of picking up the front wheels North of 180mph. When it then started to lurch toward either the centre line or concrete wall, the temptation was of course to steer in the opposite direction. With that not being effective, I found a better way was to turn the wheel towards the direction of travel - if it was still carrying the front end, most of the time it helped bring it back, but of course when the front wheels do touch down, there's only a brief moment to correct it before you're toast. Quite how they work as rudders as I was never really sure, they didn't have Mooneyes wheel discs or any aero covers attached to them.

With Bloodhound, it's easy to forget just how big and how heavy it is; there's a lot of mass that creates great big yaw numbers when it starts to get jiggy. Along with Thrust SSC, the onboard video is a good demonstration of why driving fast in a straight line isn't as simple as some would have us believe biggrin

jet_noise

3,475 posts

129 months

Monday 11th November
quotequote all
ArmouredBiscuit said:
deejay005 said:
Amazing.

Andy makes it look so easy at the wheel when it must be absolutely bloody terrifying.

Solid brass kahoonas and no mistake.
Indeed.....he talks over the radio like he's on a Sunday afternoon sightseeing tour bus, not doing 500mph with his arse inches from the ground and jet engine behind his head.

100% OG.
The man to whom even Buster Gonad bows down smile.