G/F class lakester in Wichita, Kansas

[SPARKY]

boundary  flow is the possible reality

laminar flow control is the fantasy  YMMV

[WOODY@DDLLC]

So this begs the question:  Where should the front axle be place on a Lakester?

Between the wheels? 

[Dr Goggles]

I'VE GOT THIS!


At the front.

Sorry but I had to.....

Anyway, getting back to earth , I do have a sensible suggestion. Every pound you have in front of the front axle is less downforce on the rear end. Put your front axle as far forward as you can if only for that reason, it is basic fulcrum stuff.

[ggl205]

boundary  flow is the possible reality

laminar flow control is the fantasy  YMMV

So, you are saying no part of a lakester can enjoy laminar air flow? I may disagree, Sparky.

Airflow over an object creates a boundary layer. If Reynolds number are low, the boundary layer can be laminar without turbulence irregardless of surface or shape. In LSR, we see much higher Reynolds numbers and now shape and surface become more important for those boundary layers not to go turbulent. I believe much of a lakester body can reasonably manage turbulent boundary and even achieve laminar properties in some areas. I am speaking of those parts of the body begining with the nose all the way back to rear axle. A round front axle can legally be faired within the rules so long as fairing does not exceed the inner vertical plane of the tire. Tire wake is another matter but it may be possible to redirect this inner wake so as not to mix with body streamlines. I periodically see evidence of this on F1 cars going back as far as 1970. Sparky, I agree that generating laminar air flows is quite difficult, even futile, on any LSR car but there are places where it can be done with little effort. I do concern myself more with common boundary turbulence and intuitively try to manage it. If I could have Woody for a week, much of this could be better optimized.
 
John

[Rex Schimmer]

Rob Freyvogel and Brandon Barnes' Project 66018 was designed and built completely around the ability of the NACA 66018 air foil shape being design specifically to have "long runs of laminar flow" to quote Abbott and Von Doenhoff. Several things are involved in obtaining "long runs of laminar flow" one is "fairness" which is the smoothness and fits of the  body (could be a problem for Sparky) sorry Sparky, the other is to have a shape that promotes laminar flow, a flat panel is not one of those shapes. If you fair the front axle properly into the front of the body you can greatly reduce or eliminate the loss of laminar flow at the front of the car, read "The Leading Edge" by Goro Tamai.

Rex

[ggl205]

If we can, I would like Woody to chime in about the BUB streamliner body. He has all the data on that shape and it is slab sided. Woody?

John

[WOODY@DDLLC]

Chime rant: Virtually all real world fluid flow is technically turbulent! Flow can be turbulent but still be smooth around a given shape. Some sail planes and experimental aircraft are achieving very high laminar flow results (on the wings) but under very controlled (& slower) conditions. [Read Bruce Charmichael's: Personal Aircraft Drag Reduction and you will find out about laminar separation bubbles, too!] IMO, Rob's toy will not quite get their results but will be far better than any other wheeled vehicle to date! E.g. Longer runs of laminar flow! High laminar flow may be a worthy techincal goal but me thinks not the highest priority for most builders! Now Blue can tell us we're all full of s**t [salt?]! While BUB may appear slab sided there is subtle curvature and shaping designed to improve the pressure gradients within the design limits imposed by safety considerations, packaging and the rule book! It's all a compromise guys! Besides almost anyone's sexual appliance can go 400 mph with 1500 HP laminar flow or not!  Chime over! 

[Tman]

So this begs the question:  Where should the front axle be place on a Lakester?

In the front Marty!

[SPARKY]

My first introduction to air flow was airplanes and then gliders and sailplanes.  On a lakester just the tire squirt of salt spray is going to kill most laminar flow but maybe not boundary control efforts.   YMMV

I would like to quote my favorite German Red Hat holder, " You can spend millions in design, wind tunnels and construction and have it all undone by sitting in the sun for 15 minutes."  May not be exact but pretty darn close and I have witnessed on the salt exactly what he is referring to.  YMMV

[tauruck]

IMO with enough horsepower you can make a barn door fly.

[ggl205]

My first introduction to air flow was airplanes and then gliders and sailplanes.  On a lakester just the tire squirt of salt spray is going to kill most laminar flow but maybe not boundary control efforts.   YMMV

I would like to quote my favorite German Red Hat holder, " You can spend millions in design, wind tunnels and construction and have it all undone by sitting in the sun for 15 minutes."  May not be exact but pretty darn close and I have witnessed on the salt exactly what he is referring to.  YMMV

Hi Sparky:
I may be a little rusty on what I learned (or possibly slept through) decades ago in fluid dynamics classes but it helps to define which flow volumes we are talking about. Often, I think, when discussing laminar air flows, we tend to think of those volumes with very thin boundary layers, i.e. sail planes. Those volumes are, as you correctly state, are not very likely achieved on a lakester. Laminar flows I am talking about enjoy larger boundary layers and are not turbulent. These flows are achievable on a lakester. My concerns surround those forces that would interfere or otherwise disturb those laminar flows. I have one of those red hats too and find that when I wear it, I am no smarter.

John

[ggl205]

It was a beautiful day in Wichita, Kansas so I decided to unpack a few storage boxes of Reynard FC stuff to hang on the lakester. I hoped that moving this car around the country for nearly two decades had not lost anything important and to my pleasant surprise, it was all there. I am using a bone stock 1984 Reynard Formula Continental rear suspension and wanted to see if it all still fit. It uses the transaxle for some of the suspension mounting positions and hoped the parts were serviceable. As you can see from the images, everything is usable but needs stripping and painting. Even the rod ends and sphericals were usable. I like these a little on the worn side so they all seemed perfect. No play but loose.

I made so much progress today, I thought I would try getting into the car. Oh my, do I need to loose a few pounds. Actually, more than a few pounds. I can get in but very difficult getting out.

John

[SPARKY]

HMMMM---dam there you go dealing with the reality of the
present         74  6'2" 250#  tight 40" Wranglers pre shrunk  stiff with Uncle Authur

in the past     20  6"3" 192    tight 32" Levis  not pre shrunk  limber could but my heels behind my head  YEP stuff happens with time  LOL

[ggl205]

HMMMM---dam there you go dealing with the reality of the
present         74  6'2" 250#  tight 40" Wranglers pre shrunk  stiff with Uncle Authur

in the past     20  6"3" 192    tight 32" Levis  not pre shrunk  limber could but my heels behind my head  YEP stuff happens with time  LOL

Amen, brother, amen.

[tauruck]

I wanted to ask about the inboard lower control arms.
Aren't they going to bind under load?.
The rod end looks very close to the bulkhead.

Great build despite my question.