EcoModder.com

EcoModder.com (https://ecomodder.com/forum/)
-   Aerodynamics (https://ecomodder.com/forum/aerodynamics.html)
-   -   Enclosed trailer NOSE - suggestions? (https://ecomodder.com/forum/showthread.php/enclosed-trailer-nose-suggestions-37938.html)

drudis 10-28-2019 01:09 PM

Enclosed trailer NOSE - suggestions?
 
2 Attachment(s)
I am building my own enclosed trailer.
(Images are photoshopped of what I am about to do..., not mine, and not to scale, but the drawings and measurements are the intent of my outcome).

Overall Dimension: Basically 20 feet long, 8 feet wide, and 5 feet tall.

Looking for "interface" aero thoughts between F150 and trailer.
Is the front edge height of trailer okay...? Opinions...?

kach22i 10-29-2019 09:03 AM

Good question.

Just going off the fundamentals I would say more bang for the buck (and fabrication time wise) going a little higher than 48" and allowing a gentle 5-10 degree receding roof slope is going to do more than anything else.

EDIT:

While looking for a proper image I found a related thread in another forum that may be of interest.

https://www.dieselbombers.com/towing...o-trailer.html
https://www.dieselbombers.com/attach...iler-vnose.jpg
Quote:

Do the V-nose cargo trailers do any better?
Quote:

Uncle Bubba

This is a controversey in the trailer industry. Common sence would say that it would be a huge help over the flat front trailers. Wind tunnel studies have shown very little difference though because of the dead air area at the rear of your tow vehicle. The front of the trailer is so to speak, riding in the wake.

To make this even more confusing the real drag of the trailer actually comes from the rear of it. The flat top and sides on conventional trailers creates a vaccuum at the back of the trailer that actually is pulling you backwards. In Europe where fuel prices have been insane since the end of WWII, several trailer manufacturers have compensated for this on their enclosed trailers. We have been spoiled in this country though and most didn't really care about mileage, just a big truck with a big trailer. To see an example of this technology you can look up Brenderup Horse Trailers. They are the only company in this country that I know of using this in their trailers. They are 1-2 horse trailers that are specifically designed to be pulled safely behind a even a 4 cylinder car. From personal experience I can tell you that I have had people using mine that have loaded 2 draft horses in it and pull it with a mini van and it is amazingly easy to handle and stop.

Again, if you follow the fundamentals, an aero-cap on the pick-up truck is going to do more.

Are you at least planning on using a tonneau cover?

EDIT-2:

Looking at the original images I was assuming there was a roof, but if so - how does it open? Will sloping such a roof pose as an issue for hinges and air-springs?

We need to more about this proposed design, just have front and sides, no info on top, bottom and rear where a box cavity may be of use.

Is the F-150 tow vehicle stock?

drudis 10-29-2019 11:43 AM

1 Attachment(s)
I decided to go full V-nose (and remove my toolbox).

Reasoning for overall shape is dictated by aluminum pieces:
1. The 48" x 96" diamondplate will be the hinged lid access to the nose.
2. The 60"tall x 144"long x .050"thick will be the maximum wall height.

Guestimating that the interface between the vinyl-covered bed, and the beginning of the trailer is about the only factor I can "adjust". That is the part I am trying to maximize effort. Cannot reduce/taper/round/Kammback any of the rest of the trailer, due to constraints of cargo, and/or welding the aluminum structure complexity.

Here is my cargo:

kach22i 10-29-2019 12:46 PM

1 Attachment(s)
Here is an alternative for your consideration - see attached.

The front can be as blunt as you want, although rounded corners certainly help.

It is the tapering of the form that punches a smaller hole through the air.

Visualize a rain drop as the perfect shape, which scheme looks more like a rain drop, or even a half rain drop?

Bonus: You can now stand up at the tall end.

drudis 10-29-2019 01:46 PM

3 Attachment(s)
GREAT DISCUSSION!!! (this is what I was hoping for). ;)

Given the ORANGE line, seems like adding a significant amount of complexity to raise it some 18" (over 60" base). Which only comes to about a 5-degree slope.
To get a PURPLE 10-degree slope, you need to add nearly 3 FEET of height? Wouldnt all that frontal area, negate any effect of a more streamline flow?


What about option #4, "diamond" shaped front and roofline (pseudo-round) ?
Still with only a 5 degree slope. Yeah - that is significantly more complexity and welding time...
Is it even worth trying to get that 5-degree slope...?

freebeard 10-29-2019 03:17 PM

Quote:

I am building my own enclosed trailer.

Opinions...?
You waited until now to ask the question?

....

My first thought before I scrolled down was to fair in between the back of the fender and the front of the tail light and add a collapsible trailer tail.

Permalink #3 adds the pertinent information — the use case. I'm surprised that kach22i suggests adding frontal area. :confused:

The gold standard in these-here parts is Thee Holy Template. If you abstract it down to simple curves and add it to a trailer frame you get this:

https://ecomodder.com/forum/member-f...17-trdrp1a.jpg

It has the correct taper on the front and sides but not the top, which is the biggest deviation from the template to accommodate a rear entrance.

Just starting with a rolled face on the trailer sides would have helped. Is that race car's wing demountable?

edit:
Okay, changed my mind already. Follow Mair:

https://i.imgur.com/UxyoQ4q.png

Back to a collapsible tail, but the curved nose is instructive.

drudis 10-29-2019 03:59 PM

3 Attachment(s)
> Waiting till now...
Clarification, I am ENCLOSING an already existing trailer, and none of the existing trailer dimensions are alterable.

Here is a Googled example of the NOSE that I wish to emulate (jut found this).
Materials must be from 2x2" aluminum tubing, and sheet aluminum, cause that is what I have access to purchasing.

No, the wing is part of the carbon fiber decklid (and framing support underneath), yes - removable, but not storable elsewhere during hauling... So no, it stays on vehicle.

So I appreciate discussions, theories, suggestions... but I am extremely limited to fabricating anything extraordinary...
Mostly looking for discussions on the FRONT NOSE (entry height , angle of attack from behind F150, angle of slope, angle of V-nose...). that type of discussions.

Might add boat tail flaps on rear, once the body of the trailer is finished (dont have the rear door/ramp thought out yet).

kach22i 10-29-2019 05:19 PM

Quote:

Originally Posted by freebeard (Post 610569)
Permalink #3 adds the pertinent information — the use case. I'm surprised that kach22i suggests adding frontal area. :confused:
.........................................

Back to a collapsible tail, but the curved nose is instructive.

I was thinking of it as adding useful interior space (Bonus) and saving one's neck and back from excessive crouching.

The tidbits about a collapsible tail are good, and think that I already mentioned a box cavity tail in passing.

Quote:

Originally Posted by drudis (Post 610576)
> Waiting till now...
Clarification, I am ENCLOSING an already existing trailer, and none of the existing trailer dimensions are alterable.................

Might add boat tail flaps on rear, once the body of the trailer is finished (dont have the rear door/ramp thought out yet).

Another route (Alternate-2) could be build your simple box (not even with the front nose complexity you have expressed a desire for), but radius the front and side corners.

Using this approach you will not be adding any "frontal area" and will have taken steps to tame vortexes created by differing air pressure at 90 degree plane intersections (corners).

Oh, and of course add a box cavity similar to a tractor trailer.

I've posted where to source these curved trailer parts at least one other time in the forum, let me see if I can find it again.

EDIT: Here we go, used phrase "curve box trailer".


Fiberglass Roof Caps, V-Nose Enclosed Trailers
http://www.mirageinc.com/trailer-roofs
http://www.mirageinc.com/content/ima...orque_360.jpeg

http://www.mirageinc.com/content/ima...-trailers.jpeg

kach22i 10-29-2019 05:26 PM

Looks like closing up that tow vehicle to trailer gap is beneficial.

https://ecomodder.com/forum/showthre...van-35515.html
Quote:

Originally Posted by freebeard (Post 547875)

The below is flawed in that the wheels are not fully enclosed and no evidence of a box cavity similar to tractor trailers, but close to my most recent Alternative-2. Yours would be shorter, are you flexible enough to hunch it all the way down? Perhaps a front hatch would prevent some grief.

https://www.doolittletrailers.com/tr...sed/doolittle/
https://www.doolittletrailers.com/wp...-doolittle.jpg
Quote:

Aerodynamics fiberglass front cap

freebeard 10-29-2019 05:41 PM

Quote:

Clarification, I am ENCLOSING an already existing trailer, and none of the existing trailer dimensions are alterable.
Got it.

The problem becomes defined by the back end. How much could you nip off the rear corners of a rectangular bed? Maybe use a perforated ramp instead of a solid one and leave the wing standing proud?

A lot depends on loading and unloading. Do you need access through the driver door?

You can have slab sides and put the radius in the cap. kach22i's two examples are good.

edit:
Some argumentation here about this design (the old faster backwards conundrum):
http://www.bre2.net/mm5/graphics/000...railer_lgt.jpg


All times are GMT -4. The time now is 02:16 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com