Performance of AEROTREK Fuel saving Device

[Atif]

Hello,

I am Atif, a PhD student at the University of Huddersfield. I am researching in the field of the aerodynamics of horse trailers and caravans. I have recently researched a device that shows a significant reduction in the drag force and fuel consumption. (Please see attached pictures)

This device will attach at the front of the caravan/trailer and will reduce the turbulent flow between the car and caravan. Rather than making shapes streamlined and compromising on the internal living space, the addition of this device will bring better fuel efficiency without streamlining the caravan shape. However, I have doubts about the regulation if there are any restrictions applied to this device. As you can see from the pictures, the device reduces the gap between car and caravan. Although the gap is still enough to allow free manoeuvre action of the towing car.
However, I have read online that there is a requirement of a minimum gap between the car and caravan, and someone quoted this to be 900mm. I was wondering if anyone here who had experience in this field had knowledge about this limit. Is it true to your knowledge? (I have seen in my last post that there are many experts with years of experience in the Caravan manufacturing and testing industry on this forum)

My first point of discussion is:
1. Is there a limit for the minimum gap length between the car and caravan or the gap should be long enough so that the vehicle does not interfere with the caravan or this device while manoeuvring?

2. I would like to get your feedback on this device. Here are some outstanding benefits of this device:

• Better fuel efficiency and longer journeys for electric cars.
• Reduced side wind loads and improves the stability of the caravan
• Provides front cover to the caravan

What are your major concerns about this device?
What kind of fixing mechanism would you prefer?

1. Permanently fixed
2. Detachable with mounting brackets attached to the caravan permanently.

Further detail of this device can be found on this link: http://aerotrailers.co.uk/aerotrek
I am working on the animation of this device and will add it to this link very soon. This link is not for marketing purposes, but it is a part of my PhD work to evaluate market potential for this device.
If you visit this link and, you are interested to reduce fuel consumption and you want to buy this device or want to hear more about this or any future development, please click on the buy now button and leave your email.
I would really appreciate your extra time and efforts if you can fill this quick questionnaire as well. This will provide me with some evidence about the potential customer and design feedback for my thesis. here is the link and it would not take more than 2 minutes:

Customer Survey Questionnaire

Hi, this is a quick market interest survey as a part of my PhD research degree. We have succeeded to develop a flow modifier device name Aero-trek for caravans and horse trailers which can save you more than 10 % fuel and longer battery life for electric cars. Aero-trek provides a front covering...

forms.gle

I am really looking forward to having a great discussion with you. If you have any questions, please drop them in the comments section. I will try to answer them.

Thanks
Atif

 

[Buckman]

If you take into consideration the cost of manufacturing the device for a niche market, there is no way it will pay for itself through savings in fuel consumption over a lifetime.
Not sure how it is going to be attached to the front of the caravan and what do you do with it once on a camping site? How would you clean it after each use? What sort of weight does it add to the front of the caravan as many caravans are limited to a maximum of 100kg on the tow hitch?

 

[Damian]

Looking at the link there are some wildly exaggerated claims,

1. Where is the proof of 10% fuel saving? the item is not even made and has not been tested.

2. Reduction of strong sidewind effect,,,,,,it does nothing to reduce the effect of a strong sidewind as the caravan is still a very big slab sided trailer, and the fitment of the item is to the front of the van, increasing the size of the slab.

Then there are the more important points:

Cost? how much, how heavy, how to store on site? how is it fixed to the van?

 

[Thingy]

I would ask the OP if he has ever towed a caravan, loaded and advise him to make a start from there. You cannot just pluck an idea out of thin air and make it work without practical experience of the field you are looking at.

When you consider all of this, no thought has been given to the practicalities of this in real time use.

Sorry to burst your bubble, but its a no from me.

 

[Buckman]

Another is that legally the body length cannot exceed 7m and if this is attached to the caravan the body length may be exceeded. Big question is how is it attached to the caravan.

 

[Thingy]

Its either got to be a permanent fiixture or fitted just for towing. Considering that a large percentage of caravanners are elderly and/or inform, it would be a hell of a job to fit. Where are the caravans front windows. One of the big selling points with manufacturers are these alrge panoramic windows, which are getting bigger year on year. This as a permanent fixture has not just made it darker, but seriouslt reduces potential ventilation an on a hot day.

And as Damian says, it will do nothing to improve a caravans suseptibility to side wind forces.

 

[Buckman]

On another forum they mention that unit would fold up to fit in the boot of your car and cost will be about £200 - £300. However I doubt if they have taken into consideration that the front of caravans can differ widely from one brand to the other i.e. widths and shape. Also on the other forum no mention of fitment and weight. Not even a video showing you how it is to be fitted, but plenty of icons to "Buy Now".

 

[Thingy]

Exactly Buckman.

He states

I am working on the animation of this device and will add it to this link very soon. This link is not for marketing purposes, but it is a part of my PhD work to evaluate market potential for this device.

Yet the link takes you straight to a buy it now page on its own website. So this thing is already in existence.

Another thought, how are you going to get to the jockey wheel and electrics in an emergency. The image on the website isnt even a real car and caravan btw. Im beginning to sniff something very odd here.

 

[Parksy]

It's good that somebody has put some thought into a fitting that could save fuel for towing vehicles and although I don't want to be negative, this fitting reminds me of the old wind reflectors that some caravanners used to fit on the roof of the towing vehicle back in the day.

 

[Damian]

Yet the link takes you straight to a buy it now page on its own website. So this thing is already in existence.

Taken from the website in the article:
Sorry but Aerotrek is just not ready for purchase yet

 

[Atif]

On another forum they mention that unit would fold up to fit in the boot of your car and cost will be about £200 - £300. However I doubt if they have taken into consideration that the front of caravans can differ widely from one brand to the other i.e. widths and shape. Also on the other forum no mention of fitment and weight. Not even a video showing you how it is to be fitted, but plenty of icons to "Buy Now".

Hi Buckman,
you are right about different front shapes. and I do have this into consideration. The mould and pattern can be developed to cover different frontal shapes. Because this is still in the research phase where I am simulating in the software for different configurations to find optimum position and shape.
There are many design challenges highlighted by other members on this and other forums. I will keep those in mind while further developing this product.

As I mentioned in the post this is not a sales pitch but just to evaluate the idea and see how many people are interested. Buy Now is just an option to gather interest data. The product is not developed yet but it is in the software testing phase. I really appreciate your comments and how critically you have evaluated this product.
Thanks

 

[Atif]

It's good that somebody has put some thought into a fitting that could save fuel for towing vehicles and although I don't want to be negative, this fitting reminds me of the old wind reflectors that some caravanners used to fit on the roof of the towing vehicle back in the day.

Thanks for your positive comment. Please fill the questionnaire that will be a big favour.
Thanks

 

[Lutz]

Presumably the deflector is supposed to fit snugly against the body of the caravan, without any gaps. There is bound to be some relative movement between the deflector and the caravan body while being towed. As a consequence there would be a danger of scuffing of painted body panels, especially if the deflector is thin-walled and somewhat flimsy for weight saving - another problem that needs to be addressed.

 

[Atif]

Taken from the website in the article:
Sorry but Aerotrek is just not ready for purchase yet

That page was just for further information and animation will be added soon. That will show the product in detail and will explain some of your questions too.
Please fill the questionnaire, that will be a big favour.
Thanks

 

[Atif]

Presumably the deflector is supposed to fit snugly against the body of the caravan, without any gaps. There is bound to be some relative movement between the deflector and the caravan body while being towed. As a consequence there would be a danger of scuffing of painted body panels, especially if the deflector is thin-walled and somewhat flimsy for weight saving - another problem that needs to be addressed.

Hi Lutz,

Fixture will be attached on caravan sides and this device will attach to that fixture.In the next phase I will be doing testing on the actual caravan. I will keep these things in my mind.
Thanks

 

[Buckman]

That page was just for further information and animation will be added soon. That will show the product in detail and will explain some of your questions too.
Please fill the questionnaire, that will be a big favour.
Thanks

Why do you need a persons name, contact phone and email details?

 

[Atif]

Exactly Buckman.

He states


Yet the link takes you straight to a buy it now page on its own website. So this thing is already in existence.

Another thought, how are you going to get to the jockey wheel and electrics in an emergency. The image on the website isn't even a real car and caravan btw. Im beginning to sniff something very odd here.

I am really sorry you get annoyed by the website. That is just made as a part of survey. There is not real device at this stage. But this survey and website page was made to collect people interest. I have noticed this point of accessing jockey wheel and toolbox. I will definitely consider this now for my further research. The caravans I have seen have jockey wheel close to the towing hitch. Thanks for pointing out this point.

If you can complete the survey. I will be grateful.
thanks

 

[Atif]

I would ask the OP if he has ever towed a caravan, loaded and advise him to make a start from there. You cannot just pluck an idea out of thin air and make it work without practical experience of the field you are looking at.

When you consider all of this, no thought has been given to the practicalities of this in real time use.

Sorry to burst your bubble, but its a no from me.

Hahaha. You are right I never towed a real caravan. I did tow a small 750KG trailer. The first stage was to see if there is an area of improvement for fuel saving which is evidently yes. I have run many simulations and different configurations.

Practical testing is the next phase of research. I will definitely have enough data from this forum to keep an open mind while further designing the product. I really appreciate your critical assessment of the product.
Thanks

 

[Atif]

Why do you need a persons name, contact phone and email details?

they are optional. you can essentially leave them empty. Important data I need is those questions. I hope it's not too annoying.
Thanks

 

[Thingy]

Sorry if I appeared negative, Im still not convinced you will ever get this to fly. When you initially said it was purely research and then everything pointed to a sales pitch i.e. the website....well, im naturally suspicious. When then looking at the website with a buy it now in evidence, and then no apparent genuine company contact details, the alarm bells naturally start ringing.

I think you face some massive design challenges and I genuinely dont see it as being viable. As you say, you have no practical caravan experience, and of course we have, its easy to see the problems with this. As for myself, we go away three or four times a year, but for long periods. A 10% saving of fuel 4 times a year just isnt worth the effort. I suspect you may be better served aiming this at the transport industry and try to improve what already exists. You will notice that some of the blue chip companies already have some wierd and wonderfull shapes of trailers on the road, so somebody somewhere is giving this some thought.

 

[Beachball]

Sorry it not for me i don"t do enough mileage a year to want one .

 

[Lutz]

Although it is clear that the shape and size of the deflector must be specific to each model of caravan, such as for 2.3m wide and 2.5m wide versions, I would expect that, for maximum aerodynamic improvement, the form must also suit the body and roof style of the towing vehicle, too, whether SUV, saloon car, hatchback, or estate car.
It is also doubtful whether the deflector would be of similar benefit if the towing vehicle is fitted with a roof rack.
All this makes the deflector very specific to each individual combination.

 

[Damian]

Fixture will be attached on caravan sides and this device will attach to that fixture

What "fixture" do you think that will be.
Caravan side panels are not strong enough to go fixing anything to them, and also , if done, would invalidate the water ingress warranty.
Are you prepared to cover the cost of repairs due to your "fixture"?

 

[Hutch]

Another is that legally the body length cannot exceed 7m and if this is attached to the caravan the body length may be exceeded. Big question is how is it attached to the caravan.

Buckman I think its the Chassie that cannot exceed 7 meters , not including the A frame, look at the length of some glider trailers.

I stand corrected.

 

[ProfJohnL]

Hello Atif.


Thankyou for updating us on the development of your idea.


At least our previous comments have not stopped you taking it further.


Regarding point 1 about the dimensions for coupling systems. You might find this of some use

https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=celex:31994L0020



Point 2

Your presentation on this occasion has again made some quite startling claims for the “fuel saving”. I did ask you previously how you calculated the “fuel saving” for which we did not get a reply, and I note that Damian has also now asked for clarification about how you are calculating them. This is a crucial aspect of your claims that needs to be spot on, as it is the only metric that's going to determine whether it is cost effective or not for users. - So please tell us how you are relating aerodynamic modification to fuel saving and what other factors you are taking into account to determine your fuel saving figure. For example how universal will teh savings be with different vehicles?


You mention reduced side wind sensitivity. To be honest I cannot see how increasing the effective side area of a caravan is going to reduce the effect of side winds. The same thrust per unit area over a bigger area is going to produce a bigger net effect.


Side winds should not be confused with bow waves created by moving vehicles passing the caravan.These act in a very different manner to side winds, and a narrow active line of pressure moves along the side of the caravan and causes the caravan to try and turn horizontally around its wheels and the direction of the torque effect changes and the line of pressure passes the axle.


When it comes to methods of fixing, Permanent is not really an option as most caravans have a large window at the front and the purpose of that is to allow occupants to see outside. Unless your device is transparent and easily cleaned it will need to be demountable.


Another area of concern is what forces and in what directions are likely to be generated by the device when the outfit is running at speed, as that will largely determine what fixing method is going to hold the device securely. Will such strong fixings need to be on reinforced sections of the caravan?


You might consider using the awning rail, and some caravans do have bead-in-groove rails fitted to both sides of the caravan, but some only to one side, so that is an uncertain proposal, and you would need to know if they will comfortably manage the forces the device will generate.


I feel I must comment because I get the impression that you may not have really studied the general design of caravan coupling systems. You should have certainly already found out about minimum clearances etc, much of that information can be found on line or made available through university library’s and should be a fundamental part of product utilisation research, to make sure your test models are as realistic as possible.


Another concern I have relates to the models shown in your CFD runs. The underside of a caravan has fairly substantial chassis members and these form an “A” frame and will direct underfloor air to the sides of the caravan. This may alter the assumptions you have made about the air flow down the sides of the caravan.


I very strongly urge you to go and look at real caravans to see some of the practical limitations of the designs, and how your product needs to interact.

PJL