New here. Aerodynamics questions

[TomCat60]

Hello all,

I am doing research on building a pop up truck camper and have come up with a design plan I want. Now I seek to understand if or how I can make it aerodynamic at highway speeds.

I just tried to attached a picture but for some reason it only lets me attach a website address BUT first I need to post 5 times. So hello to everyone :-)

Thanks in advance
Tommy
Northeast Washington State.

[TomCat60]

I have 5 post now so here are a few pictures of the pop up truck RV camper I want to build. My truck is full size with a 8 foot bed and a 2 foot tail gate so mine will be about 3 feet longer then this one and won't have the cut in corners on the back either. Share your thoughts on making it aerodynamic please.....

http://www.hookedupfilms.com/huf-camper-part-viiii/

[aerohead]

The ability to telescope up and down as shown is limiting all the leading edge radii as well as longitudinal radii necessary for a drag minimum.
I'd guess that the camper shell has about Cd 0.7.Like a early 1970s JEEP.
*You need a minimum of 80mm radius on the leading edges just to maintain attached flow onto the shell.
*Something like a 'NOSECONE' brand style fairing shaped nose would be ideal.
*An 80mm radius down the top sides won't cut the Cd but it will really help with crosswind stability as far as rolling moments go.
----------------------------------------------------------------------------All the things necessary to cut drag really amplify the difficulty of fabrication.
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An upside down aluminum boat,nose first,mounted above the camper might help.

[TomCat60]

*Something like a 'NOSECONE' brand style fairing shaped nose would be ideal.


I am totally new to this subject. Would something with a general shape on this truck on the top front of the camper workout for me ? Would it help much at freeway speeds ?

https://www.google.com/search?q=nose...on%3B418%3B297


Thank you for replying to my questions
Tommy

[redneck]

Aerohead

An upside down aluminum boat,nose first,mounted above the camper might help.

6. An aerodynamic front profile nose cone and cab bubble was added to our camper. The cab bubble is an inflatable cushion that is wedged between the top of the cab and the sleeper. It keeps the wind noise and drag down. We have been really surprised by how quiet the camper is during travel and we can still hit 80 MPH with no problem. Plus we are averaging 17.5 mpg (with conservative driving) which is not to bad for a four wheel drive home on wheels.

Adventure Americas Travels to South America in a Truck Camper

>

[ennored]

Originally Posted by aerohead

*You need a minimum of 80mm radius on the leading edges just to maintain attached flow onto the shell.

Wow, only 80mm? I had a much bigger number in my head. Especially for a wide vehicle (again my frame of reference being my 8.5' wide RV).

This has stuck in my head:


(From page 29 of the 2011 NASA report "Fairing Well")

They used a 2' radius. Yes, greater than 80mm, but A LOT greater.

[elhigh]

Originally Posted by TomCat60

*Something like a 'NOSECONE' brand style fairing shaped nose would be ideal.


I am totally new to this subject. Would something with a general shape on this truck on the top front of the camper workout for me ? Would it help much at freeway speeds ?

https://www.google.com/search?q=nose...on%3B418%3B297


Thank you for replying to my questions
Tommy

Yes, the shape you show would be an improvement.

Looking at the original pop-up and its leading edge, compared to the leading edge of the cube van in this example, the cube van would be a huge improvement. It has a pretty large radius so you give up some interior space, but that space is likely in a sleeping loft so practically speaking it wouldn't amount to a big functional loss.

If you can come up with a way so that your pop-up slopes toward the rear in an increasing radius (look at the aerodynamic template to see how it looks) when collapsed, that will do much to reduce the aero load on the vehicle when moving. You're not the first to want to have a spacious camper without having to pay the big aero penalty, check it out:

https://www.youtube.com/watch?v=mRT9GvIW25w

[freebeard]

Welcome to Ecomodder.


I created this for a thread here: Replacing Class c motorhome body for touring act

It was modeled on 1930s beer trucks.


Also, consider the pop-top/aero combination here:


ennored -- I don't have a citation, but IIRC it's expressed as 4% of gross width. 4/96 puts that in the ball-park as a rule of thumb.

[Thenorm]

Originally Posted by TomCat60

I have 5 post now so here are a few pictures of the pop up truck RV camper I want to build. My truck is full size with a 8 foot bed and a 2 foot tail gate so mine will be about 3 feet longer then this one and won't have the cut in corners on the back either. Share your thoughts on making it aerodynamic please.....

HUF Camper Part VIIII | Hooked Up Films

ugh, that linked camper is awful (aerodynamically). so square. cool that it is carbon fiber.

[TomCat60]

Yes carbon fiber is very light and strong too. 3 inch walls with 18 R value is sweet for winter camping but those thick walls make it pretty ugly. lol
Tommy