Wing Tanks that need a lift.........

1FATGMC · February 13, 2005, 11:54:49 AM

Quote from: "PeterR"
QuoteThe tanks I'm trying to get are definitely too short (will need an added center section) and might not be wide enough or tall enough to use as is. I feel it will be easier to take too small of a tank and add filler pieces to make it bigger than to start with too large of a tank and try to make it smaller.

Sum,
A few years ago I was doing work on a streamline float that was to be fabricated from flat panels much like the way a barrel is formed from flat strakes.

I developed a procedure to plot the actual shape of the segments in their flat form from the length, diameter, and the NACA coords of the aerofoil section. Even using as few as 8 flats the finished shape looks quite respectable. If you decide to build a body from scratch you are quite welcome to use this or I can run the figures through for you.

If you have concerns of the cross section being a series of flats rather than a smooth shape, remember for a solid body fully immersed in a fluid the drag is profoundly influenced by the shape in side view, but the shape of the cross section viewed from the front has no bearing on the drag, only the cross section area.

I think I can visualize what you are talking about, but a crude sketch or more detail would be appreciated. You could post it here or PM me, whichever you wanted to do.

You are correct about the comments about drag. One thing I like about the oval shape of the E-Z Hook Streamliner is it makes the sides flatter which with the air going down them gives the body a shape that helps with stability in addition to the tail.

Thanks for the input,

Sum

Fat Cat · February 13, 2005, 12:06:17 PM

Quote from: "1FATGMC"You could post it here or PM me, whichever you wanted to do.

Thanks for the input,

Sum

I myself would prefer it to be posted here. I am getting an education, and would like to continue to learn about this topic.

Bib_Overalls · February 13, 2005, 12:43:27 PM

When I was in the 7th or 8th grade my walk to and from McKinley grammer school in San Gabriel took me close to the home of hot rod pioneer Bill Burke. I could look up his street and if the garage door was open I would detour to look at his belly tank streamliner. At the time I did not know he was the first to run one of these puppies on the lakes.

Although I was not old enough to grasp the significance of what I was looking at I am sure this early influence is partly responsible for my all consuming hot rod obscession.

If you do a web search on "bill burke belly tank" you will find some interesting links to belly tank lakes racing history. Yahoo gave me 6 or 7 hits. Web Crawler produced 19.

unklian · February 13, 2005, 03:13:38 PM

QuoteI think I can visualize what you are talking about, but a crude sketch or more detail would be appreciated.

I think he's talking about how a hexagon cross section,
viewed from the front,could be as aerodynamic as a circle.

Are cross winds a problem at Bonneville ? :?:
Some shapes work better in a cross wind.

1FATGMC · February 13, 2005, 03:57:05 PM

Quote from: "unklian"Are cross winds a problem at Bonneville ? :?:
Some shapes work better in a cross wind.

If I remember right they shut things down with wind speeds greater than 20 mph, but it might be 15.

c ya, Sum

Elmo Rodge · February 13, 2005, 05:54:46 PM

Quote from: "Bib_Overalls"When I was in the 7th or 8th grade my walk to and from McKinley grammer school in San Gabriel took me close to the home of hot rod pioneer Bill Burke.

I used to ride my bike past his house about the same time. I knew who he was but was too shy and stupid to stop and look closer. I finally introduced myself to him at the 200 Club Banquet at Speedweek last August. Neat guy. I'm currently building a P-38 Tank (Flathead powered) and I crew for Jack Kelly on his Tank. I also crew for Wilson and Waters on their Fuel Roadster but this thread is about Tanks.

Wayno

PeterR · February 14, 2005, 03:46:58 AM

QuoteI think I can visualize what you are talking about, but a crude sketch or more detail would be appreciated.

QuoteI think he's talking about how a hexagon cross section,
viewed from the front,could be as aerodynamic as a circle.

Correct, that is exactly the message I wanted to convey.

If an object is completely immersed in a fluid --like an aeroplane is fully immersed in air, or a submerged submarine is completely immersed in water, then the actual shape when viewed front-on does not appreciably affect the drag, only the cross section area. This means if the cross section is round, oval or square, the drag is the same for the same cross section area. (Extremes of a very thin cross section like an aircraft wing which have a tiny frontal cross section but large surface drag are a different matter altogether.)

The only reason I mentioned this in the earlier post is that I had referred to aerofoil shaped floats, and the drag of a partially immersed object such as a conventional boat or a surfaced submarine, is heavily dependent on the cross section shape, and I was expecting someone here to question the suitability of a float section for a streamliner.

Now your specific questions. The shape in side view (and plan view) is a typical aerofoil developed either by entering the NACA coords to produce the mathematical curve, or by "kicking the curve" into whatever shape you like. The overall length and fattest diameter are then entered, followed by the number of "flats" that form the cross section. If you remember pictures of the old airships like the Hindenburg and R101, they were an aerofoil shape viewed from the side, but front-on you could see the cross section was a series of flats where the fabric pulled taut over the stringers, this has a similar appearance.

The more flats, the closer the cross section shape is to a circle, but the more pieces to cut from the flat sheet and the more joins to make. The good thing is that you choose the diameter and the length to suit your particular requirements, but there is a lot of assembly work and it is only worth embarking on this option if the ready-made drop tanks do not eventuate or require a lot of modification.

It has been some time since I looked at this but from memory it only handled a cross section with width and height equal, producing an even square, hexagon, octagon etc. I will check tonight.

PeterR · February 14, 2005, 09:55:50 AM

Quote from: "PeterR"
It has been some time since I looked at this but from memory it only handled a cross section with width and height equal, producing an even square, hexagon, octagon etc. I will check tonight.

Only does strip profiles for cross sections having same height as width, but there is a way of cheating to achieve a section which is taller.

Start with a cross section that is the desired width, then add an extra vertical side panel which is formed from a parallel strip. It would look like one of those two-piece fibreglass tanks with a vertical section stacked between the two halves to give extra height but retaining the same width.

This allows length, width, height to be chosen individually.

1FATGMC · February 14, 2005, 08:13:41 PM

Quote from: "PeterR"
Quote from: "PeterR"
It has been some time since I looked at this but from memory it only handled a cross section with width and height equal, producing an even square, hexagon, octagon etc. I will check tonight.

Only does strip profiles for cross sections having same height as width, but there is a way of cheating to achieve a section which is taller.

Start with a cross section that is the desired width, then add an extra vertical side panel which is formed from a parallel strip. It would look like one of those two-piece fibreglass tanks with a vertical section stacked between the two halves to give extra height but retaining the same width.

This allows length, width, height to be chosen individually.

Thanks Peter, when you posted I had in my mind those old air ships. Sounds like that all would work.

The latest on the tanks is I think Benny found a way to get them up to Oklahoma City and then hopefully I can get them from there to Utah when I go through there in April.

Thanks to everyone who has offered help on this. I'll let you know if and when I get them if I'll be able to use them. I'm sure I will in one form or another.

c ya, Sum

Lakester Construction In
Progress

PeterR · February 14, 2005, 08:43:26 PM

QuoteThe latest on the tanks is I think Benny found a way to get them up to Oklahoma City and then hopefully I can get them from there to Utah when I go through there in April.

Getting them home should not be too difficult, bore a hole at the back, pour in a few gallons of Jet-A, point them in the right direction, then light the wick.

Elmo Rodge · February 14, 2005, 08:59:15 PM

Quote from: "PeterR"
QuoteThe latest on the tanks is I think Benny found a way to get them up to Oklahoma City and then hopefully I can get them from there to Utah when I go through there in April.

Getting them home should not be too difficult, bore a hole at the back, pour in a few gallons of Jet-A, point them in the right direction, then light the wick.

On the subject of transporting Tanks, when I picked up my P-38 it was with a flat trailer and motorsickle tie-downs. Work with me here. Take some string and try to tie an egg to a plate. :? Wayno

tomslik · February 15, 2005, 06:25:46 AM

Quote from: "Elmo Rodge"
Quote from: "PeterR"
QuoteThe latest on the tanks is I think Benny found a way to get them up to Oklahoma City and then hopefully I can get them from there to Utah when I go through there in April.

Getting them home should not be too difficult, bore a hole at the back, pour in a few gallons of Jet-A, point them in the right direction, then light the wick.
On the subject of transporting Tanks, when I picked up my P-38 it was with a flat trailer and motorsickle tie-downs. Work with me here. Take some string and try to tie an egg to a plate. :? Wayno

how about one or 2 of those spider net things?

flt-blk · February 15, 2005, 08:56:00 AM

Where exactly in SE Texas are we talking?

I might be able to get them from FtWorth to OKC, or at least be a storage spot.

I neve should have sold my driver truck.

1FATGMC · February 15, 2005, 01:30:31 PM

Quote from: "flt-blk"Where exactly in SE Texas are we talking?

I might be able to get them from FtWorth to OKC, or at least be a storage spot.

I neve should have sold my driver truck.

They are in Orange, east of Beaumont on I10. Looks like that is quite a ways from Fort worth. Only about 7 inches on my map, but it says over 300 miles.

I appreciate the help, but I'm hoping we have it covered with the truckers Benny knows. He said that if he would have had them at his house the other day they would be in Oak City now.

If we have problems I might be contacting you.

I'm hoping that tieing them down won't be a big problem as they have some pieces sticking out of them where they attached to the wing and it shouldn't be too hard to use those to tie them down.

Thanks again,

Sum