Travel Trailer/Camper help

[Ecobalt]

I am so used to pitching a tent way back in the campsite under the trees. Now, I am going to have to put up with sleeping in a tin can that has been in the sun all day. That's the way it will have to be if we want to camp out in the Sierras or the Smokies with our precious aminal.

[slowmover]

So long as you all stay out of the deep South or desert West in summer I'd imagine any of those split systems will work.

On a trailer like mine, from 28' on up in size, a pair of A/C units is practically mandatory if one wants the interior to cool to below 80F. My next trailer will be a 32' or 34' and conversion to 50A service with dual roof A/C units is a given. Aero fairings will be on the list to investigate (around here is an example shown). I just need to find a tin bender who'll work with me.

As my roof will also have solar panels, an antenna farm, plus the usual assortment of vent openings, I've decided not to worry over a "clean" roof but to minimize the drag of each component as I go along. Utility will count over the small FE gains.

I would think a removable boat tail for a TT would trump all these roof concerns given a production model RV. Same for a nose cone of some sort.

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[aerohead]

Originally Posted by Ecobalt

I installed a mini-split system two years ago. Don't be afraid to tighten those pipe fittings! I tried to follow the "torque spec" in the manual and put them on too loose. I had to pay to have the system recharged. It did not need to be evacuated, though.

Use two real wrenches, not adjustable wrenches, and tighten them enough that the nut grabs the tubing and starts to twist the tubing with it.
***
I am still not sold on the roof top AC. Perhaps an aeromodder could build a teardrop shaped fairing that tapers back for a long distance.

It occurred to me that a minisplit AC may not have the vibration rating that a real RV AC needs. If you go that way, I would recommend shock absorbers on the axles.

orbywan has fabricated a streamlining fairing for his A/C unit.You might want to check out his RV build thread.

[aerohead]

Originally Posted by slowmover

Google Books: January 1982 Popular Science for pic of Fibrelock press release.

Now that is an excellent idea! Modifying the nose of the trailer is otherwise counter-productive as it is almost always the "lounge" or sitting area of a trailer and outward visibility from there is crucial. The rear -- bath or bedroom -- would be easier to mod (removable boat-tail) as use of the space is different. A detachable inflatable "nose" would be outstanding.

Interesting about Airstream. One of the men who worked the Airstream in-house Carvanner Insurance Co years ago stated that, by contrast, that flat-faced travel trailers tend to have a resistance to sway due to that face (nose). Experience of most all aero aluminum trailers is, however, that cross-wind resistance (yaw due to winds) is far greater, so the Hucho statement doesn't make sense. In fact I'd be hard-pressed to find anyone, owner or RV hauler, who would agree with that (as there are those with several hundreds of thousands of miles of experience, in nearly all kinds of weather, climate and terrain). I can see the amount of wind pressure varying on a rounded trailer wall, say, versus the increasing loads against a flat-walled trailer accounting for this given some time/distance stuff. (I'll request the Hucho book via interlibrary)

Closing the gap between TV and TT is without remedy (as I see it) for the majority of us. Not at all knocking anyone who tries. On my rig that gap is a full 60". I see treating each vehicle separately, mechanically (rolling efficiency) and with some aero as being most fruitful. A 5'er is more likely to see gains with truck/trailer gaps addressed.

I'm going to assume that the CM Trailer Co. in question is not the one in Oklahoma (who make an otherwise nice trailer I'm told), but cannot find otherwise a reference to these dimensions.

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I think that the concern is that around a radius,sideways lift might be generated which would induce a yawing moment affecting stability,whereas with the sharp-edged corner,it's always in separation and somehow will not create the moment.I don't have the paper Hucho refers to so I'm at a loss to understand specifically where the fear is generated.

[slowmover]

I'd like to understand this. Is it in reference to crosswinds hitting the trailer and "lifting" it 90-d to the direction of travel? That seems to be my misunderstanding, here, as my impression of that is that the wind does not "pile up" against the trailer sides as it does with a sharp-edged trailer.

If we speak of winds in the direction of travel I'm still at a bit of a loss. Yes, a square-front trailer has some "built-in" anti-sway (sheer resistance to direction of travel) over a "shaped" front (radiused edges) . . but I'm having a hard time with the claim that it is significant in trailer directional stability. Experience, etc, all otherwise mitigate this claim.

Maybe . . that even a bit of anti-sway via hitch rigging is enough to offset any tendency of this sort.

That's as close as I can come.

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[skyking]

the way the relative wind leaves a body has far more bearing on drag and lift than the way it arrives. In a crosswind situation the relative wind will stay attached a bit on the downwind side of a radiused trailer. I would speculate that this departing effect is not nearly as strong up front, in the shadow of the Tow Vehicle (TV), but more pronounced farther aft.
I don't think the flat face has any real bearing on it, compared to the aft downwind side.
A square trailer will have a long aft downwind side break that will cause a yawing force aft of the pivot(trailer axles) , in the downwind direction.
This force will steer the nose of the trailer into the wind, and consequently the nose of the TV downwind.
So that gust that seems to steer you so hard downwind in your truck is truly the "tail wagging the dog".
Now with your rounded trailer, this is not nearly as pronounced. That is why your experiences with the radiused trailers are what they are.
The relative wind over the downwind side stays attached just a wee bit better in your case. Because the trailer is radiused everywhere, it performs equally better in all conditions.
The wind does not push your trailer around, it pulls it around.

[slowmover]

Not push, but pull. Okay, that makes more sense. Thanks for the time in laying that out!

[skyking]

Any Time

[KamperBob]

Pull not push is a great explanation! A larger and/or more blunt the rear surface basically acts like a bigger drag chute. A lot of people think this new camper is aerodynamic.

[skyking]

Originally Posted by KamperBob

Pull not push is a great explanation! A larger and/or more blunt the rear surface basically acts like a bigger drag chute. A lot of people think this new camper is aerodynamic.

Well it is a bit more aerodynamic. most folks confuse entomo-dynamic with aerodynamic. If it collects fewer bugs then it must be good