RE: Jaguar Electric Powerboat: Time For Tea
Discussion
A typical lake or river in the uk is what, 5 degC tops for a lot of the year? Compare that the cooling loop of a electric race car, that under load will sit at around 50 degC. That's a big difference, and because the electric powertrain is so efficient, the actually heat rejection requirements are small. A typical 300kW electric powertrain is going to reject at most 30kW of heat, so you don't need an enormous mass flow of water (typically around 20 l/min) compared to an ICE cooling loop that runs in the hundreds of l/min and has to reject 100's of kW
Sure, which is why a Chevy V8 is being cooled through a pipe not much larger than a fuel feed.
None the less, water is over 800 times more dense than air (which means pretty much 800 times the drag), so you still can't afford to make the cooling pick-up any bigger than it really has to be.
You can't afford to over-cool a hydroplane any more than you can afford to over-cool a car, and the pay-off would need to be dramatic for it to be worthwhile as a means of increasing power.
If the demands of an electric motor are so much reduced compared to IC, and for a short-duration record run, it might be worth looking at alternative solutions (dry ice?) in place of water cooling.
None the less, water is over 800 times more dense than air (which means pretty much 800 times the drag), so you still can't afford to make the cooling pick-up any bigger than it really has to be.
You can't afford to over-cool a hydroplane any more than you can afford to over-cool a car, and the pay-off would need to be dramatic for it to be worthwhile as a means of increasing power.
If the demands of an electric motor are so much reduced compared to IC, and for a short-duration record run, it might be worth looking at alternative solutions (dry ice?) in place of water cooling.
Equus said:
Sure, which is why a Chevy V8 is being cooled through a pipe not much larger than a fuel feed.
None the less, water is over 800 times more dense than air (which means pretty much 800 times the drag), so you still can't afford to make the cooling pick-up any bigger than it really has to be.
You can't afford to over-cool a hydroplane any more than you can afford to over-cool a car, and the pay-off would need to be dramatic for it to be worthwhile as a means of increasing power.
If the demands of an electric motor are so much reduced compared to IC, and for a short-duration record run, it might be worth looking at alternative solutions (dry ice?) in place of water cooling.
All true and obvious. None the less, water is over 800 times more dense than air (which means pretty much 800 times the drag), so you still can't afford to make the cooling pick-up any bigger than it really has to be.
You can't afford to over-cool a hydroplane any more than you can afford to over-cool a car, and the pay-off would need to be dramatic for it to be worthwhile as a means of increasing power.
If the demands of an electric motor are so much reduced compared to IC, and for a short-duration record run, it might be worth looking at alternative solutions (dry ice?) in place of water cooling.
As the heat rejection from an electric power train is so much less, direct water cooling is probably overkill so you could probably forego the need for in water cooling pickups and the associated drag altogether. In this instance, much lower drag direct air cooling would probably be your best bet.
dvs_dave said:
...direct water cooling is probably overkill so you could probably forego the need for in water cooling pickups and the associated drag altogether. In this instance, much lower drag direct air cooling would probably be your best bet.
I guess it will depend on how much cooling is required to deliver Max's 70kW performance boost, and the most weight/drag efficient way of achieving that.We're sweating the fine detail, though, where Jaguar is not even getting the broad brush strokes right, yet.
Having just finished a Donald Campbell biography I gave some thought as to what he’d do in order to offer vocal support to a valiant British record breaking effort. So..
I’ve sent a letter to Jaguar saying I could’ve done better with a pair of oars.
Hope they take my constructive criticism.
I’ve sent a letter to Jaguar saying I could’ve done better with a pair of oars.
Hope they take my constructive criticism.
Edited by Buggyjam on Sunday 17th June 17:27
In fairness to Jaguar, I think that this project probably has very little to do with braking the record, and a lot more to do with assessing the viability of using Formula E technology for circuit boat racing (though what their interest might be in the latter is hard to say).
They'd have been better off keeping their powder dry (pun intended) until they had something worth shouting about, but no doubt their marketing cockroaches have been baying for maximum publicity.
They'd have been better off keeping their powder dry (pun intended) until they had something worth shouting about, but no doubt their marketing cockroaches have been baying for maximum publicity.
Equus said:
The propeller driven water speed record stands at 205mph (yes, by an Unlimited Hydroplane - driven by a 3,000 SHP gas turbine aircraft engine), so 200+ with an electric motor just ain't gonna happen.
The previous record of 200mph had stood since 1962. It's not an easy record to break.
They certainly need to be looking for 120mph+, though, before they'll impress anyone in the powerboating world.
This doesn't sound right at all. There are several records; top speed after 1/4 mile from standstill iirc is 260 ish. Kilo record (sustained speed) is slower 220ish? There must be half a dozen pleasure boats (luxury offshore cats not race or record boats) on the US poker run scene that can run 200. Phenomenon has 12000 bhp; that should breeze past 205.The previous record of 200mph had stood since 1962. It's not an easy record to break.
They certainly need to be looking for 120mph+, though, before they'll impress anyone in the powerboating world.
https://www.offshoreonly.com/classifieds/skater-b2...
fblm said:
This doesn't sound right at all...
It is, I assure you.There's a difference between momentarily peaking at 260+ mph in a drag boat or hitting 220+ mph in an Unlimited Hydro at the end of a straight, and maintaining it for two runs over a measured kilometre or mile in opposite directions, within an hour of each other.
To set an official record, you also need to be sanctioned by the UIM, with a properly measured course, certified timing equipment and official observers.
Posting pictures of your speedometer on YouTube doesn't count.
ETA:
The Official records list is here.
Seems I am a bit out of date myself, though - the Unlimited Immersed Propeller record is no longer 205mph; it's been bumped up to 220mph (still by a gas turbine engined American Unlimited circuit hydroplane).
Edited by Equus on Sunday 17th June 20:14
Equus said:
fblm said:
This doesn't sound right at all...
It is, I assure you.There's a difference between momentarily peaking at 260+ mph in a drag boat or hitting 220+ mph in an Unlimited Hydro at the end of a straight, and maintaining it for two runs over a measured kilometre or mile in opposite directions, within an hour of each other.
To set an official record, you also need to be sanctioned by the UIM, with a properly measured course, certified timing equipment and official observers.
Posting pictures of your speedometer on YouTube doesn't count.
ETA:
The Official records list is here.
Seems I am a bit out of date myself, though - the Unlimited Immersed Propeller record is no longer 205mph; it's been bumped up to 220mph (still by a gas turbine engined American Unlimited circuit hydroplane).
Edited by Equus on Sunday 17th June 20:14
Equus said:
fblm said:
This doesn't sound right at all...
It is, I assure you.There's a difference between momentarily peaking at 260+ mph in a drag boat or hitting 220+ mph in an Unlimited Hydro at the end of a straight, and maintaining it for two runs over a measured kilometre or mile in opposite directions, within an hour of each other.
To set an official record, you also need to be sanctioned by the UIM, with a properly measured course, certified timing equipment and official observers.
Posting pictures of your speedometer on YouTube doesn't count.
WTFWT said:
Spirit of Qatar hit 244mph over the measured mile at Lake of the Ozarks and only had a one mile run up. It was deliberately under propped to get the rpm up and would have gone faster with more space. Cracking video of the run on YouTube
Well, Spirit of Qatar needs to make an official record attempt, then.Otherwise, it has the same status as me telling you that I once hit an indicated 100mph in my Mini City, downhill and with a following wind... or, for that matter, Stan Barrett claiming that the Budweiser Rocket went supersonic for a few yards, one-way at Edwards Airforce base, according to a plot on military radar.
If it's not been officially sanctioned and timed, it don't count for s
t.Equus said:
Well, Spirit of Qatar needs to make an official record attempt, then.
Otherwise, it has the same status as me telling you that I once hit an indicated 100mph in my Mini City, downhill and with a following wind... or, for that matter, Stan Barrett claiming that the Budweiser Rocket went supersonic for a few yards, one-way at Edwards Airforce base, according to a plot on military radar.
If it's not been officially sanctioned and timed, it don't count for st.
Why so spiky? Otherwise, it has the same status as me telling you that I once hit an indicated 100mph in my Mini City, downhill and with a following wind... or, for that matter, Stan Barrett claiming that the Budweiser Rocket went supersonic for a few yards, one-way at Edwards Airforce base, according to a plot on military radar.
If it's not been officially sanctioned and timed, it don't count for s
t.I didn’t say SoQ has broken a UIM sanctioned record, just that it is common, verifiable fact that propellor driven boats, other than drag boats can break 220mph.
Winning the mile shootout at LOTO confers slightly more credibility than you bragging about a Mini City, regardless of what you may believe.
WTFWT said:
Why so spiky?
Not being spiky - just telling it how it is.Yes, I'm perfectly aware that drag boats momentarily peak at higher speeds than the official record.
So do boats that break official records....
Momentary peak speeds don't constitute a record, and that's all there is to it. Them's the rules.
Equus said:
Yes, I'm perfectly aware that drag boats momentarily peak at higher speeds than the official ....
Spirit of Qatar is a 50 foot Mystic; an offshore powerboat designed to run 50-100 miles in a race (not that there's currently a class for it). A top fuel drag boat hits 265 in 3 seconds and is done; totally different. In any event as you've already said the kilo record is not 205 any more which is hardly surprising when you see some of the speeds people are reaching in pleasure cats on the shootout and poker run scene. You can get over 3000bhp from Mercury with a warranty now!
fblm said:
Spirit of Qatar is a 50 foot Mystic; an offshore powerboat designed to run 50-100 miles in a race (not that there's currently a class for it). A top fuel drag boat hits 265 in 3 seconds and is done; totally different. In any event as you've already said the kilo record is not 205 any more which is hardly surprising when you see some of the speeds people are reaching in pleasure cats on the shootout and poker run scene. You can get over 3000bhp from Mercury with a warranty now!
My point was that in terms of peak speed, drag boats are currently the fastest things with propellers.
An unlimited Hydroplane currently holds the official speed record, properly timed, over a two-way average.
Spirit of Qatar is an irrelevancy: it's neither the fastest in terms of peak speed, nor holder of any official record. As you say yourself, there's not even a race class for it. LOTO is an unsanctioned Redneck Regatta, not recognised by either the UIM or the APBA.
Max_Torque said:
A typical lake or river in the uk is what, 5 degC tops for a lot of the year? Compare that the cooling loop of a electric race car, that under load will sit at around 50 degC. That's a big difference, and because the electric powertrain is so efficient, the actually heat rejection requirements are small. A typical 300kW electric powertrain is going to reject at most 30kW of heat, so you don't need an enormous mass flow of water (typically around 20 l/min) compared to an ICE cooling loop that runs in the hundreds of l/min and has to reject 100's of kW
For this kind of effort surely you could get away with a closed (with pressure relief) container full of ice with the coolant loop through that? Shove loads of heat into the phase change, then you've got another 100C to go to another phase change, then start dumping steam. It'd be rubbish for an endurance event but it doesn't strike me as something that'd be awful to model. Then just model the effect of that mass on the drag of the hull and compare to a suitably sized open-circuit cooling setup?Equus said:
And?
My point was that in terms of peak speed, drag boats are currently the fastest things with propellers.
An unlimited Hydroplane currently holds the official speed record, properly timed, over a two-way average.
Spirit of Qatar is an irrelevancy: it's neither the fastest in terms of peak speed, nor holder of any official record. As you say yourself, there's not even a race class for it. LOTO is an unsanctioned Redneck Regatta, not recognised by either the UIM or the APBA.
And? Well it was you who claimed 205 was the record and then assured us you were right when I questioned it and it's you who's now wibbling about drag boats when the boat that ran 244 is a 50 foot Mystic. The point is stock consumer poker run boats that anyone can buy with a warranty are snapping at the heels of 200 mph; theres even a 210mph turbine mystic for sale currently for less than $600k. The rednecks have moved things on from plucky Brits tuning little car engines.My point was that in terms of peak speed, drag boats are currently the fastest things with propellers.
An unlimited Hydroplane currently holds the official speed record, properly timed, over a two-way average.
Spirit of Qatar is an irrelevancy: it's neither the fastest in terms of peak speed, nor holder of any official record. As you say yourself, there's not even a race class for it. LOTO is an unsanctioned Redneck Regatta, not recognised by either the UIM or the APBA.
fblm said:
The rednecks have moved things on from plucky Brits tuning little car engines.
The WWSR hasn't been about plucky Brits tuning little car engines since... well, ever.Since as far back as you care to take it, it has been about aero engines. It's still about aero engines.
If Spirit of Qatar were to set a prop-driven record, it would be in the tradition of multi-aero engine boats like Gar Wood's Miss Americas. But it hasn't, so I'm not sure why you continue to bleat about it.
It doesn't hold any records, it's not the fastest boat in terms of peak speed, it's not got the range or the robustness to challenge any serious distance records, and it's not capable of racing in any legitimate class. It's an irrelevancy.
Was the owner your boyfriend?
Gassing Station | General Gassing | Top of Page | What's New | My Stuff