If you are really interested in studying something about fluids

[Harold Bettes]

Hey Guys,

There seems to be some level of interest in fluids as it applies to poking a hole in the air - Fluid Dynamics can be studied without massive amounts of grief with mathmatical approaches. IF you can drink a cold one, that in itself is a stage of fluid dynamics! There are many good books that are worthwhile to check out of the library and decide if you want to add the volume to your own library for reference.

I have spent most of my adult life studying airflow in some form or another, and it can become an addictive passion that is great fun to share.

One of the great books for gearheads on the subject is Fluid-Dynamic Drag by S.F. Hoerner, 1965. Another is Fluid-Dynamic Lift by the same author (co-written by Henry Borst).

There are many others, but some lack the practicality of Hoerner's work. From time to time, I will lob another title out that might help kick a hole in the wind for you and yours.

Hopefully, the reference will be of interest to some of you during the winter time.

Kind Regards to All,
HB2

[Harold Bettes]

OK, I get the point. -0-

Maybe I should have had a subtitle that read: Free Beer. Well, that is a fluid.

How many of you guys have ever considered that some of the vehicles that ended up on the salt had models tested at the Air Force Academy?

The "field installed" aero modification kits that have been done on many of the C-130 gun platforms actually were developed by AFA Cadets! Allowing a reduction in aero drag of more than 15%.

Regards to All,
HB2

[JackD]

OK
You want comment ?
I will never stand in the back of a 130 and deliver "Daisey Cutters" again and you can't make me.  LOL

[Bob Jr.]

OK, I get the point. -0-

Maybe I should have had a subtitle that read: Free Beer. Well, that is a fluid.

We are racers after oil and fuel it's BEER!!!!

[Hans Blom]

harold, I see exactly what you mean about studying areo. I am a mechanical engineer/hotroder, not necessarily in that order and have become fascinated with aerodynamics. this is mainly due to building a non streamlined bike which is VERY un-aerodynamic. Keep bringing on the references!

Hans

[Harold Bettes]

Hans,

I too, have the cursed academic education of mechanical engineering. Normally you can spot us at any mall - very actively pushing on doors that are plainly marked "pull". In my opinion, any engineer can become much better at his/her craft with a classical gearhead approach toward learning. "Why does that work that way?" or "How does that work?" so that practical application is an important part of refining one's discipline and ability to contribute.

Kindly remember a few things about fluid flow (airflow in general and aerodynamics in specific): Airflow is not intuitive (sorta like thermodynamics) and one must learn the nuances and rules to apply.

Relative to your bike: The problem is not typically the entry (fairings are examples), but the exit losses are where the real gains can be made. During a study of a particular bike for Bonneville, it was found (in tunnel testing) that the bike was "cleaner" without a fairing in place. OH Blasphemy!

I will try and chase up some information for you that is related to these kind of applications. In the meantime, try and find a library copy of Hoerner's Fluid Dynamic Drag and his Fluid Dynamic Lift.

For your particular bike: Are there any plastic models available?

One can build a simple profile tunnel for very little money and "see" how clean or how dirty a configuration is or may be. No, they are not perfect, but very useful devices. IF I can figure out how to include photos on this gig, I will do so.

Regards,
HB2

[Harold Bettes]

By the way Hans, I have a dear friend that lives/works in Lillesand, Norge.

Regards,
HB2

[Carl Johansson]

Hey Harold,
I went looking for a copy -  105 bucks on Amazon - I don't suppose it would be available on the internet as an electronic copy ?

105 bucks for a book I probably can't understand -  sounds about right!

Carl Johansson

[Harold Bettes]

Carl et al,

When a book costs that much, always hit the library. Even if they don't have it, they can get it for you on an inter-library loan.

I do not think that Hoerner's stuff is available on any electronic media.

Regards,
HB2

[Harold Bettes]

Some books that are much more affordable than Hoerner's stuff:

Race Car Aerodynamics by Joe Katz, 1995, Robert Bently Publishers, ISBN 0-8376-0142-8

Automotive Aerodynamics Handbook, Henry Landa, 1987 (6th edition), ISBN 0-931974-14-3

Try out the library first so that you can see (read) them and decide if you should add to your own resource library.

Regards to All,
HB2

[SolsticeRacer]

Harold,

I just started studying aero to improve a friends LSR bike.  I'm just getting started, but someone recommended "The Leading Edge - Aerodynamic Design of Ultra-streamlined Land Vehicles" by Goro Tamai, from 1999.  It's relatively inexpensive (~$40) and the first couple chapters have been very good.  But it's written with solar cars in mind, so it's not a perfect fit to LSR.  But there's lots of good info on canopy design, and detailing at junctions.  And it's written in a very accessible/practical way, not knee deep in theory though it's included.

I've got a copy of the Hoerner book from the library now, but haven't gone through it yet. 

Thanks,

Matt

[Harold Bettes]

Thanks for the heads up on the book.  I don't recall, but don't think that I have seen that one. I will check my library.

Just remember a pretty good rule of thumb about aero stuff: IF it goes faster than 40MPH, then the details begin to tally. It is that nasty speed cubed thing. Aero drag is a whole lot easier to come by than the power to overcome same.

Regards to All,
HB2

[Hans Blom]

Harold,
Lillesand is a beautiful place, down on the southern most coast. I visted there this summer on the way to see my 98 year old grandmother(muts be the goat cheese and congnac) . I am in Bergen on the west cost working with Black gold, Texas Tea that is. One aspect of aero dynamics that <i have not found much info on is concerning airflow of a rotating wheel/tire and how it varies with respect to width/height/rpm etc.  There is lots of info on static blocks of X moving through a medium, but  not too much on this type. Unfortunately the libraries around here are a little lacking in these types of books...not to mention in <norwegian...actually most anything very advanced at all is in English. Makes me think of back in the day the University gave away a wind tunnel due to not having room for it...it was onyl 2' x 2' x 6' mabey, but you can do alot with that!

Hans

[Harold Bettes]

Hans and guys,
Yes, that small tunnel would be handy today! That would be one of the best ways to pass the winter.

I have been pretty distracted lately and have not had time to carefully look through my books for a good suggestion on the open wheel issue. Hoerner is the first that comes to mind.

I think that the HP Books piece on aero is pretty weak, but as I recall it had some stuff on open wheels. I just don't recall.

Hope to come up with something soon. 

Regards to All,
HB2