Flat front trailer vs V-nose 6x12

racerx217
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racerx217 9/27/2019 6:30pm
9/27/2019 6:30pm
Had a 6x10 haulmark flat front trailer and a 2011 Serra with the 5.3 and a 6 spd. I use to get around 11mpg. Now have a 2017 f150 with the eco boost 2.7L and now pulling a steel 7x16 with a V nose and average 12-13.
sumdood
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sumdood 9/27/2019 6:41pm
9/27/2019 6:41pm Edited Date/Time 10/1/2019 8:44am
MxKyle (MD) wrote:
These posts are killing me because I actually have all the answers but haven't completed the follow up. Like everyone else I bought an enclosed trailer...
These posts are killing me because I actually have all the answers but haven't completed the follow up. Like everyone else I bought an enclosed trailer and was appalled by how bad my mileage was. From 23 to 10 or 11 mpg and I was routinely doing 1200 mile trips. Unlike everyone else I am a senior mechanical engineer with lots of training in air flow analysis. I spent at least a year of my free time trying anything I could think of to reduce the drag on a model of my F150 pulling a 6X12 V nose. Necessity is the mother of invention they say and I needed to do better than 10 mpg.

I started with the rear and made 20 iterations of the trailer tail you see on the semis. I saw improvement on the simulation but it was only about 5% which is actually what the Trailer Tail company advertises. I didn't consider that worth much as changing wind conditions will cause your mileage to very more than that.

I tried many many louver systems to try to redirect the flow into the low pressure drag area behind the trailer but found that anything I added created even more drag and offset any improvements I might have gained in the rear.

Finally, I arrived at a truck mounted spoiler system that is different than anything you have ever seen. Kind of funny looking actually but what the hell. The simulation showed such a major reduction in drag that I thought I have made a mistake in my analysis (I use Solidworks Flow BTW). After checking it a half dozen times and getting the same answer I ponied up the $70 for the materials and built the first prototype. I tested the spoiler by first towing the trailer. five miles out and another five back on a flat straight highway with little traffic and got 9.9 mpg. I added the spoiler and immediately did the same route to the tune of 16.6 mpg. Better that a 60% increase in mileage. Total success!

Now I have shelved the spoiler while I do patent searches and try to figure out how to market the idea. I'm too old to start a business and just want to sell the idea. This is way harder that you might think. The spoiler is so easily understood and copied I can't even use it until I get a patent and find someone to buy it. I just drove another 1200 mile loop and had to eat the $120 dollars my spoiler would have saved me.

--KT--
So you get a patent or whatever you need yet ? Come on dude step it up this your exit plan. Plus I want one.
2
Rhody
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Rhody 9/27/2019 8:49pm
9/27/2019 8:49pm
MxKyle (MD) wrote:
Entertain yourselves with some real data. I am always amazed how much force is applied to the road in front of the truck as the pressure...
Entertain yourselves with some real data.

I am always amazed how much force is applied to the road in front of the truck as the pressure wave is pushed along.

This is with a topper but runs without the topper were not much worse. In other words the addition of a topper didn't help much in reducing the drag. Before you jump to the obvious conclusion of putting an airfoil on the topper I found that the drag of adding the airfoil was about the same as the drag removed from the front of the trailer so no overall improvement.


Can you show the low pressure areas at the back of the vehicles? That is a huge part of the equation that people miss. Also, the air bubbles surrounding the vehicle influence the drag. Your flat nose trailer builds a high pressure area between itself and the back your truck. This high pressure area acts on the back of your truck, canceling out the force pushing back on your trailer. The V nose will let this high pressure bubble collapse, forcing your back window and tailgate to tow along a low pressure area. It's not intuitive, but it is real.
RF145
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RF145 10/1/2019 7:06am
10/1/2019 7:06am
49weasel wrote:
1 mpg doesn’t really matter to me but 2-3 does. We ride or race every weekend. Loaded down yesterday I averaged 18.5 mpg. My truck is...
1 mpg doesn’t really matter to me but 2-3 does. We ride or race every weekend. Loaded down yesterday I averaged 18.5 mpg. My truck is 9 months old and I have 23,000 miles on it , so I drive a lot.
I’m contemplating suffering through buying 5x10. Between the trailer and truck bed I would have excess space but having to duck to get in or out might get old real quick.
Weasel, what you really only need to look at, is your mileage on riding/racing weekends.How many of those 23,000 miles which occur during your unloaded weekdays do not figure in.

If you put pencil to paper, this might be a moot thread.

Say you drive 1000 miles per month with a trailer, 12,000 per year. Loaded down you are getting 18.5 MPG without the trailer. Using $2.50 a gallon avg fuel cost, your 1000 miles cost you $135.14 that month.

Worst case, you lose 5 MPG with the cheaper trailer, your fuel will only be $185.18.

So, the cheaper, larger, more comfortable trailer costs you at the most $50.00 a month, $12.50 a week.

You can not find $12.50 every week so you can enjoy this trailer? Stop looking at MPG's, Look at the actual cost.

Obviously I made up these numbers and if the gas is cheaper by you or you drive more than 1000 miles per weekend, my post will not reflect your costs, but this is a much better way of really looking at the benefit cost ratio.
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Jamie_English Jr. 10/22/2019 9:20am
10/22/2019 9:20am Edited Date/Time 10/22/2019 9:23am
Why does not just make an Aerodynamic trailer that is lightweight and easy to load and unload. Oh wait, they do, 5 different sizes of them in fact and they are just made for motorcycles. They still have a low roof line and the top pops up to get out of the way. They cost a little bit more than a regular trailer but they save you the fuel and towing woes. 4 year warranty on the new ones too. www.ironhorsetrailers.com




1
oilcan1001
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oilcan1001 4/14/2020 10:05am
4/14/2020 10:05am
MxKyle (MD) wrote:
These posts are killing me because I actually have all the answers but haven't completed the follow up. Like everyone else I bought an enclosed trailer...
These posts are killing me because I actually have all the answers but haven't completed the follow up. Like everyone else I bought an enclosed trailer and was appalled by how bad my mileage was. From 23 to 10 or 11 mpg and I was routinely doing 1200 mile trips. Unlike everyone else I am a senior mechanical engineer with lots of training in air flow analysis. I spent at least a year of my free time trying anything I could think of to reduce the drag on a model of my F150 pulling a 6X12 V nose. Necessity is the mother of invention they say and I needed to do better than 10 mpg.

I started with the rear and made 20 iterations of the trailer tail you see on the semis. I saw improvement on the simulation but it was only about 5% which is actually what the Trailer Tail company advertises. I didn't consider that worth much as changing wind conditions will cause your mileage to very more than that.

I tried many many louver systems to try to redirect the flow into the low pressure drag area behind the trailer but found that anything I added created even more drag and offset any improvements I might have gained in the rear.

Finally, I arrived at a truck mounted spoiler system that is different than anything you have ever seen. Kind of funny looking actually but what the hell. The simulation showed such a major reduction in drag that I thought I have made a mistake in my analysis (I use Solidworks Flow BTW). After checking it a half dozen times and getting the same answer I ponied up the $70 for the materials and built the first prototype. I tested the spoiler by first towing the trailer. five miles out and another five back on a flat straight highway with little traffic and got 9.9 mpg. I added the spoiler and immediately did the same route to the tune of 16.6 mpg. Better that a 60% increase in mileage. Total success!

Now I have shelved the spoiler while I do patent searches and try to figure out how to market the idea. I'm too old to start a business and just want to sell the idea. This is way harder that you might think. The spoiler is so easily understood and copied I can't even use it until I get a patent and find someone to buy it. I just drove another 1200 mile loop and had to eat the $120 dollars my spoiler would have saved me.

--KT--
sumdood wrote:
So you get a patent or whatever you need yet ? Come on dude step it up this your exit plan. Plus I want one.
Yes, please hurry......I want one also !!!
Motogoof
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Motogoof 4/14/2020 6:29pm
4/14/2020 6:29pm
I’m in . I’ve been waiting to see this thing for ages.
LumpDog841
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LumpDog841 4/14/2020 6:44pm
4/14/2020 6:44pm Edited Date/Time 4/14/2020 6:58pm
MxKyle (MD) wrote:
And you have to know the manufactures have done this analysis but they know that sporty looks sell better than an ugly truck with good gas...
And you have to know the manufactures have done this analysis but they know that sporty looks sell better than an ugly truck with good gas mileage.
So up until last October I was an analysis engineer (structural FEA not fluid CFD) working at GM. I can promise you that there are about a billion hours spent doing CFD analysis which is then validated in the wind tunnel. I've personally sat in numerous meetings where pretty heated discussions took place on how to meet all the aero/structural/gov requirements that go into a vehicle. Concerning your contour plot above remember the front of the vehicle is open not a wall the air flows into the engine bay. Nice work BTW!!
MxKyle (MD)
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MxKyle (MD) 4/15/2020 7:37am
4/15/2020 7:37am
LumpDog841 wrote:
So up until last October I was an analysis engineer (structural FEA not fluid CFD) working at GM. I can promise you that there are about...
So up until last October I was an analysis engineer (structural FEA not fluid CFD) working at GM. I can promise you that there are about a billion hours spent doing CFD analysis which is then validated in the wind tunnel. I've personally sat in numerous meetings where pretty heated discussions took place on how to meet all the aero/structural/gov requirements that go into a vehicle. Concerning your contour plot above remember the front of the vehicle is open not a wall the air flows into the engine bay. Nice work BTW!!
That would be absolutely correct but probably more important would be that I didn't fully model the structure under the truck or the frame of the trailer. Overall I decided the drag induced by those areas are negligible compared to the drag of the forward facing structure. The results from the proof of concept test drive showing only a couple of percentage points from the analysis results tells us the strategy was valid.

I seriously doubt that anyone at your level has been doing drag analysis on our truck and trailer problem. This area of concern is really outside of the general market for pickup trucks. Maybe a trailer company would be working the problem but I doubt they employ engineers at that level. That is where I am hoping to sell this design BTW.

I have contacted one of the 'Take Your Design to Patent' companies for help. I don't know how long this will take but I hope it's not long.

--KT--
rbspecial138
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rbspecial138 4/15/2020 10:17am
4/15/2020 10:17am
redrider_714 wrote:
Don’t know how true this is but I was told by a dealer that v-nose will give you a little bit less mpg because it has...
Don’t know how true this is but I was told by a dealer that v-nose will give you a little bit less mpg because it has 2 surfaces in the front instead of 1 flat surface. Guess it causes more wind resistance. Never had a v-nose so I can’t confirm or deny this.
kkawboy14 wrote:
2 surfaces to hit? What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit...
2 surfaces to hit?

What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit 2 surfaces or 1?
It does hit two surfaces... Take the square footage of the flat panel, now take the square footage of each side of the V and add them together... which square footage is higher? This is how friction works. More surface area CAN (in some cases) equal more friction.
yak651
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yak651 4/15/2020 10:23am
4/15/2020 10:23am
redrider_714 wrote:
Don’t know how true this is but I was told by a dealer that v-nose will give you a little bit less mpg because it has...
Don’t know how true this is but I was told by a dealer that v-nose will give you a little bit less mpg because it has 2 surfaces in the front instead of 1 flat surface. Guess it causes more wind resistance. Never had a v-nose so I can’t confirm or deny this.
kkawboy14 wrote:
2 surfaces to hit? What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit...
2 surfaces to hit?

What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit 2 surfaces or 1?
rbspecial138 wrote:
It does hit two surfaces... Take the square footage of the flat panel, now take the square footage of each side of the V and add...
It does hit two surfaces... Take the square footage of the flat panel, now take the square footage of each side of the V and add them together... which square footage is higher? This is how friction works. More surface area CAN (in some cases) equal more friction.
Yeah I usually laugh at Kkawboy's post but it would actually be 3 surfaces, the 2 sides + the little rounded area between the sides...
rbspecial138
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rbspecial138 4/15/2020 10:39am
4/15/2020 10:39am
kkawboy14 wrote:
2 surfaces to hit? What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit...
2 surfaces to hit?

What a complete idiot, that guy should never do anything but stay in bed all day! Think about it.....does it actually hit 2 surfaces or 1?
rbspecial138 wrote:
It does hit two surfaces... Take the square footage of the flat panel, now take the square footage of each side of the V and add...
It does hit two surfaces... Take the square footage of the flat panel, now take the square footage of each side of the V and add them together... which square footage is higher? This is how friction works. More surface area CAN (in some cases) equal more friction.
yak651 wrote:
Yeah I usually laugh at Kkawboy's post but it would actually be 3 surfaces, the 2 sides + the little rounded area between the sides...
Yes, that is correct, if we account for every surface and use finite element analysis it could be potentially millions of surfaces depending on how complex we make the model. My main point was that I believe the salesman in question was referring that any gains you make by having an angled surface, you lose in that there is more square footage available for friction.
rbspecial138
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rbspecial138 4/15/2020 10:41am
4/15/2020 10:41am
I'm thinking this might be what MxKyle is talking about?

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LumpDog841
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LumpDog841 4/15/2020 11:03am
4/15/2020 11:03am
MxKyle (MD) wrote:
That would be absolutely correct but probably more important would be that I didn't fully model the structure under the truck or the frame of the...
That would be absolutely correct but probably more important would be that I didn't fully model the structure under the truck or the frame of the trailer. Overall I decided the drag induced by those areas are negligible compared to the drag of the forward facing structure. The results from the proof of concept test drive showing only a couple of percentage points from the analysis results tells us the strategy was valid.

I seriously doubt that anyone at your level has been doing drag analysis on our truck and trailer problem. This area of concern is really outside of the general market for pickup trucks. Maybe a trailer company would be working the problem but I doubt they employ engineers at that level. That is where I am hoping to sell this design BTW.

I have contacted one of the 'Take Your Design to Patent' companies for help. I don't know how long this will take but I hope it's not long.

--KT--
Oh Yeah completely agree, don't take anything I said as criticism. In my opinion especially with limited resources it's better to have a quick simple model that is quickly verified with actual testing, which appears to be what you did. Like I said nice work. At GM we did full CFD with a trailer and truck modeled, but the analysis is for cabin noise/boom, not drag. If you could sell your design to an OEM as an accessory part you could probably make some serious $.

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