Turbine vehicles

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David Leikvold
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afterburner

Post by David Leikvold » Mon Feb 23, 2009 11:56 pm

Thank you to everyone who has told me about the SCTA rules and to PJQ2 for the FIA links. If you look at my first response to Mr Turbine I already knew we are wheel driven only. I was surprised by the reactions of those who got upset just because I was talking about a class we don't have. I am NOT trying to get a thrust class included but if it happened anyway I'd be pleased because I always liked watching them at the drags. I'll leave that to others more involved, i.e. current owners of jet engines looking for somewhere to use them. I posted that photo because I found it a while back and I figured people might be interested.

Everyone also needs to know that I am NOT trying to be the resident antagonist, I just wanted to firstly answer a question that nobody else wanted to and to continue the discussion to a reasonable conclusion, whatever that happened to be. Having said all that I still like the idea of a Stan Barrett style car with a jet about the size of the one in Ron Patrick's new Beetle. Of course another option (and much cheaper) would be a pulse jet like the ones the Nazis used on the V1 buzz bombs (there's one at the War Memorial in Canberra). They were essentially just a three piece, 10ft long steel sheet tube with a reed valve, a fuel spray, a start-up ignition source and nothing else. At altitude they could do 400mph in level flight. To stop them all you'd have to do is turn off the fuel pump (just like a Top Fuel car). The 50hz flame out the back was about 15ft long! And LOUD!

Reverend H, the safety aspect you mentioned could be easily solved by using the ignition cutoff that jet skis use, just run a cord from the rider's leathers to a switch on the bike. I think the bike rules already require one. I agree with you about wheel driven, the challenge is very different with a thrust car, the huge power of any jet isn't the problem it's keeping the car down to a safe speed for the tyres. But despite all that they're still great to watch and I'd love the technical challenge of getting one up and running hard. Imagine one of these non-existent cars with afterburner on full streaking into the sunset on a timed "exhibition" run after the racing for the day was over!
Good, Fast, Cheap, pick any two!

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Reverend Hedgash
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Re: afterburner

Post by Reverend Hedgash » Tue Feb 24, 2009 9:56 am

David Leikvold wrote:Imagine one of these non-existent cars with afterburner on full streaking into the sunset on a timed "exhibition" run after the racing for the day was over!


I'm imagining that right now, sitting at the canteen, beer in my hand, streak across the salt... very nice.

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Lynchy
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Post by Lynchy » Tue Feb 24, 2009 2:44 pm

streak across the salt


Wasn't that a team mate of yours? On a Vespa....?

Oh - and Dave is a lovely bloke in real life and should never be confused with Rat Lips! He will be down at the lake to discuss roof chops and jets!!! hahaha
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Reverend Hedgash
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Post by Reverend Hedgash » Tue Feb 24, 2009 2:49 pm

ahhh yes. Not so nice.

The funniest thing as the Doc got his daks off was a cry from one of the ladies from the Moe Boys camp that came braying across the lake, "That looks like a penis... only smaller!!!"
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Lynchy
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Post by Lynchy » Tue Feb 24, 2009 3:01 pm

.................and the belly tank looks like.............?

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Reverend Hedgash
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Post by Reverend Hedgash » Tue Feb 24, 2009 3:20 pm

We have decided that each year it will be a different colour so we can look at a photo and say, "Crikey, that is from 2009!".

Also we have lots of ideas of different liveries and want to try them out.

Most importantly it is the last thing we do and is always a crap hurried job but hopefully will improve year in and out.

We are sticking to the red and white as per my avatar on the landracing site for this year...

We have painted the red, the cream scallops are going on this weekend.

So how does sh look? Well... it'll probably photograph Ok from about 20feet... but don't look too close.

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David Leikvold
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Location: Brisbane

paint

Post by David Leikvold » Wed Feb 25, 2009 1:06 am

Rev, don't go to any trouble to make the paint nice. I read somewhere that golf balls have better aero because of the dimples and sharks have sandpapery skin which gives them less drag in the water than a smooth skin. So turn up that air pressure and start spraying for an orange peel finish, it'll probably go faster!

And yes, I will be at the lake, my leave has been approved! I look forward to my first visit to the lake with great excitement. Lynchy, enough of the lovely bloke business, next thing you know Bob will... oh no, don't go there. Mind you, that million bucks would come in handy!
Good, Fast, Cheap, pick any two!

David Leikvold
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Location: Brisbane

Dear FR

Post by David Leikvold » Wed Feb 25, 2009 1:29 am

I haven't taken much notice of Franklin, I tend not to read dreary blogs that go nowhere, but has he really been trying to get his swamp boat/car thingy approved for 7 years? Kinda makes Gordon D look like a remarkably reasonable man, doesn't it. Franklin, if you're reading this, stop wasting your life. Give up your quixotic crusade. Go find a donor car and build something wheel driven (and fast enough to be fun) for an obscure class so you can claim a record, get in the 200mph club and actually use a car you built and have some fun. If nothing else, some of the people you don't like will hate that you went faster than them! Success is the best revenge.
Good, Fast, Cheap, pick any two!

PJQ2
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Post by PJQ2 » Wed Feb 25, 2009 10:00 am

I've actually got a bit of respect for the talented mind of Mr. Ratliff. He's a legit Rocket Scientist. It's the communication and interpersonal skills that are sadly off the beam.

Bit like admiring the communication and PR skills of Adolf Hitler and the Nazi party. Ya gotta draw a solid line somewhere.
Regs,
PJQ
Velocity Science Laboratories

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Reverend Hedgash
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Post by Reverend Hedgash » Wed Feb 25, 2009 10:09 am

The Nazis were good at rocket technology. Also a dab hand at some Landspeed records.

A problem recently arose with the restoration of some of those hoopy Auto Union racecars that were being restored in that they sported quite predominent swastikas originally.

To apply censorship and deny history in the restoration, or to restore something that would be considered by some to be the promotion of Nazi activity...?

Glad we don't have that problem.

As for rough surface paint David, we have looked into what you say already. Ideally you have it placed behind the point of separation to create a slight turbulence to help maintain layer attachment for longer.

The only person I know using it on the salt is that damn Mazda 13B driven by that crazy red headed beekeeper.

As for golf ball its all about the Reynalds nuimber and generating lift, not smoothness of flow...

Interesting idea though and as we fine tune the car we will consider all things again, at the moment, the effects of these things are of a order of magnitude too small to concentrate on.

Look forward to having a chat at the lake, come up and introduce yourself.

Dik

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Graeme H
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Post by Graeme H » Wed Feb 25, 2009 12:47 pm

www.ronpatrickstuff.com

How about a jet powered VW - Road Registered - :shock:

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Lynchy
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Post by Lynchy » Wed Feb 25, 2009 3:57 pm

Hey Rev

To apply censorship and deny history in the restoration, or to restore something that would be considered by some to be the promotion of Nazi activity...?

Glad we don't have that problem.


The old Holden Dealer Team cars aren't allowed to display the Marlboro signage anymore and same goes for any tobacco sponsored racecar from any era. So we do have the same problem. Tobacco companies may not be nazi's but they get censored as well.

Ideally you have it placed behind the point of separation


Wouldn't it go before the point of seperation to create the turbulence to then maintain attachment?
I thought that the theory of dimples on golf balls is twofold. 1 - to reduce drag by having turbulent air in the wake thus minimising drag to a degree. (this is also the theory behind vortex generators that you can buy and stick on your car). 2 - to increase lift and therefore increase the distance that the ball is in the air. Not good for a car.

I wouldn't think dimpling a car would help it at all. Similarly polishing a car has no benefit either.

Rob
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Post by Rob » Wed Feb 25, 2009 8:04 pm

Knock yourself out with golf ball theory here.

http://www.aerospaceweb.org/question/ae ... 0215.shtml

It's actually quite an interesting read.

If you're not up to it, the important sentence says the dimples are to reduce drag and thus increase length of flight.


To the best of my knowledge, there's no lift generated by a sphere dimpled or not unless it's induced by spinning.

Cheers,
Rob
I owe, I owe, so off to work I go.

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Reverend Hedgash
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Post by Reverend Hedgash » Thu Feb 26, 2009 10:05 am

Thanks Rob but here is the rest of the enchilada...

How a Golf Ball Produces Lift

In 1877, British scientist P.G. Tait learned that a ball, driven with a spin about a horizontal axis with the top of the ball coming toward the golfer produces a lifting force. This type of spin is know as a backspin.

The backspin increases the speed on the upper surface of the ball while decreasing the speed on the lower surface. From the Bernoulli principle, when the velocity increases the pressure decreases. Therefore, the pressure on the upper surface is less than the pressure on the lower surface of the ball. This pressure differential results in a finite lift being applied to the ball.


The dimples help in the generation of lift. By keeping the flow attached, the dimples help promote an asymmetry of the flow in the wake. This asymmetry can be seen the image attached. In this figure, the smoke shows the flow pattern about a spinning golf ball. The flow is moving from left to right and the ball is spinning in the counter-clockwise direction. The wake is being deflected downwards. This downward deflection of the wake implies that a lifting force is being applied to the golf ball.


Curtesy of the "The K-8 Aeronautics Internet Textbook" apologies for not attaching the image but it is as described. It can be checked at http://wings.avkids.com/Book/Sports/ins ... lf-01.html

I think the only way to resolve this is by bringing a set of clubs to the salt and putting a hole in at... say the 9 mile mark? Should be a par 5 I reckon with the dimples and appropriate wind direction...

Alan Shepherd's six iron on the moon probably stemmed from some similar discussion at the NASA canteen about dimples and no atmosphere!

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David Leikvold
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Joined: Mon Apr 16, 2007 11:57 pm
Location: Brisbane

speaking of jets

Post by David Leikvold » Fri Mar 20, 2009 11:46 pm

Speaking of jets, we were on our way home, somewhere between Burra and Morgan when we saw a RAAF Hornet doing low slow circuits. I waved out the driver's window as he went past and to my complete surprise he wiggled the wings back at me. We pulled over and watched as he did two more circuits right in front of us, the first flying level and the second with the nose well up. Those of you who were at Indy a few years ago will remember just what a fabulous noise they make when they're dancing a Hornet on it's tail. Yeah baby!!
Good, Fast, Cheap, pick any two!

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