Bloodhound LSR: High speed testing: 491mph

Land Speed Record

Since our last newsletter, so much has happened that we wanted to send you an update on our progress now, rather than wait until high speed testing has finished.

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Every day out here has been full of activity and we have gathered so much data to learn from. But the overriding thrill is, of course, watching the car accelerate down the track – especially knowing what it takes to get the car to that point – all the different Engineering disciplines working together.  With a top speed of 491mph (780km/h) already, Bloodhound LSR is unofficially the third-fastest British car ever. As a team we knew that getting to 500mph (800 Km/h) shouldn’t be a problem. It is from this point that the real testing begins. Over the next two weeks, we will be gently pushing the car faster through the transonic region, carefully analysing the data between runs to ensure we proceed safely to the next step. The excitement in the team is tangible. We are now settled into the routine of being here and are stepping up another gear as the next set of runs become more challenging.

The runs we’re doing here in 2019 are not designed to break any records, the media attention is giving us a taste of what it will be like when we return for those record-breaking runs.

Our time here hasn’t been without its challenges, however. The engineering team has had to tackle a range of issues – although to be honest, I think I would have been worried if we hadn’t discovered anything that needed fixing, as engineering projects are never 100% perfect from the start. The team has had to do brilliant detective work to fix some of these, as there is no Haynes manual for a one-off straight line racing car.

The weather has thrown up some challenges too, particularly the wind. If you watch the video of Andy driving runs 2 and 3  (which were done one after the other), you can see how much difference a crosswind makes and hear Andy comment on what we’ve learned about the realistic maximum crosswind speed Bloodhound can handle. Discoveries like this are also an important part of high speed testing.

Finally for now, I’d like to once more thank the local Mier Community and the Northern Cape Government for creating the best high speed race track in the world. Now that we’ve run the car six times, we know for sure that it really is what Andy and the team had dreamed of as the ideal surface for straight line racing. Rudi – our track master – can be seen on his video giving heartfelt thanks to the local people he has been working with over the past 8 years.

Please keep watching our progress on social media and sending us your feedback. We wish we could have brought you all out with us this time to see the car run, but our comms team is doing the next best thing and posting as much as they can to keep you up to speed.

Yours,
Ian Warhurst, CEO, Grafton LSR Limited

In this issue

  • High speed testing update, plus videos
  • Run Profile 4 – why the engine shut down unexpectedly first time round
  • The Bloodhound Shop is open!
  • Find your name on the fin and download your certificate
  • Keep up to date with high speed testing on social media.
  • Support Bloodhound LSR

High Speed Testing Update

In the last newsletter, we reported that the team and car had arrived safely in South Africa. Since then, the engineering team has assembled the car, including its solid aluminium desert wheels, successfully fired up the EJ200 engine and started the high speed runs.

The preliminary work wasn’t without its challenges. The team had to get the Bloodhound computers to talk to the EJ200 engine as well as get the engine started after a inhibited storage (compounded by higher altitude and temperatures than in the UK), fix a water leak and solve electrical problems. But they successfully tackled everything that was thrown at them. This is one of the reasons for coming to South Africa for high speed testing – to draw out all of these issues and solve them now, rather than when we’re here for the record runs.

Having solved the initial issues, and once our launch event  was over, we turned our eyes to the race track, where the run lines had been marked out by a GPS-controlled tractor. Our high speed testing in South Africa consists of a series of runs, each with a pre-agreed run profile*. That way, everyone knows not only what speed Andy will drive the car at, but also what we’re trying to achieve and learn each time.

At the time of writing, Bloodhound has successfully completed run profiles 1 to 6, with a top speed of 491mph (790km/h) and successful deployment of the parachute for braking, which is fantastic!

It hasn’t been completely plain sailing though. We’ve encountered more challenges during these runs, including both technical problems (see Ian’s report below for an example) and weather issues – mainly cross winds, for which we’ve now confirmed the limit is 10mph. You can find out more about all of this on our social media channels, but we’ve listed some key videos below that will bring you up to speed.

* You can see the list of planned run profiles  on the website as well as reports on each one. The HST number in a run report refers to the actual number of the run itself, not the run profile number, as we sometimes have to do more than one physical run to successfully complete the targets set in a single run profile.

Videos

  • Getting the EJ200 started  – Chief engineer Mark Chapman talks through successfully starting up the jet engine for the first time (despite some teething problems).
  • Run Profile 1 – Static engine test followed by 100mph run.
  • Getting ready for Run Day 2  – Operations director Martin Roper talks through preparations for the day and the tricky weather conditions on the Pan.
  • Run Profiles 2 & 3  – Ian Warhurst summarises a day that saw Bloodhound run at 200mph and then 334mph; a new top speed for the car, but also a very windy day!
  • Run Profile 3  – Ride onboard with driver Andy Green as Bloodhound reaches 334mph.
  • Run Profile 4  – Target 400mph, first attempt. Systems lead Joe Holdsworth explains why the engine shut down around 20 seconds into the run.
  • Run Profile 4 (second attempt)  – Target max reheat up to 400mph, then slow down by deploying the parachute for the first time – Success!

Find more #2019HST videos in our High Speed Testing 2019 YouTube channel.

Run Profile 4 – Learning about Bloodhound’s sensitivity issues

Ian Warhurst explains what happened during the initial attempt at Run Profile 4 – this is an example of the kind of issue we’re seeking to expose and solve during high speed testing, so that we don’t have to deal with them during the record runs.

During the first attempt at Run Profile 4, Andy accelerated the car to 150mph but then experienced an unexpected engine shutdown.

After analysing the data, it appears that the ‘engine on/off’ switch experienced a 10ms ‘off’ event, which instructed the engine controller to shut down the engine. This coincided with a spike load on the suspension loading.

Watching the video replay from the rear and side cameras, we could clearly see that the event was triggered when the car passed over one of the areas of the track which had recently been graded. (The location is a local shortcut across the Pan, so any vehicle ruts had to be filled in before we used the track.) This clearly gave a jolt to the suspension – but that’s exactly why the car has suspension.

The switches in the cockpit are digitally controlled but do have a physical connection. This means when the switch is subjected to any vibration, the connection can experience ‘flutter’. To deal with this, and prevent false switching, a flutter delay is coded into the software which tells the CPU to ignore the ‘off’ signal unless that signal lasts for longer than a pre-set length of time.

When the engineers investigated the cause, they found the coding had been set to be very sensitive. This is a normal default for safety, but meant that the engine CPU had picked up and reacted to the 10ms event. Once discovered, however, a simple fix could be put in place to set a more realistic limit for Bloodhound. The code has now been updated to ensure all the switches have a 300ms flutter buffer, which is about the equivalent to actually operating the switch.

As a further check, the team analysed the suspension data and found that although it was quite a jolt, it was operating within normal limits. We’ve also visited that portion of the track to check the severity of the area causing the load spike.

Kit yourself out in new Bloodhound LSR gear

If you’re a Bloodhound fan and inspired by our success in South Africa, show your support through our brand new merchandise in the official Bloodhound online shop, which is now open for business!

We’ve got a range of clothing  in Bloodhound team colours, including t-shirts, polo shorts, hoodies, caps and a great jacket. This includes a limited edition HST2019 t-shirt. Alongside the clothing, we have merchandise including mugs, drinks bottles and rucksacks.

Get yours now while stocks last – and remember, Christmas is less than 2 months away, so it’s the perfect time to buy presents for any Bloodhound fans in your family!

Fin name certificates

If you paid for a ‘Name on the fin’ before Grafton LSR bought Bloodhound, your name has already travelled at hundreds of miles per hour along Hakskeen Pan in South Africa!

Find your name by using the link below to download a high res PDF and use the ‘search’ function to scan.

Find my name on the tail fin.

Support Bloodhound LSR

Bloodhound LSR welcomes sponsorship from all sizes of organisation. As interest in the success of our high speed testing continues to grow, now is an ideal time to get involved.