Wind Turbine on the grill of the car

[JTG15]

Hi, I'm currently in High school so I'm uncertain whether this could be feasibly possible. I read on another thread that Wind Turbine's produce too much drag to actually be beneficial to your car and energy. BUT, they all discussed the wind turbine being on the top of the car.

I was thinking, what if the turbines were placed on/inside the grill of the car. Obviously, they'd have to be open to the wind hitting them, but if they were placed on the front of the car instead of on top would this eliminate the drag problem?

Now, I'm sure it wouldn't be enough to actually power the car on its own, but would it be possible as a second energy source, as let's say, a backup, emergency source for electric cars?

And would it be worth it economically?

Just a thought.

 

[Averagesupernova]

If you reduce drag you will also be reducing the power taken from the wind turbine. No wind turbine on a vehicle will ever increase the efficiency or range. It is a net loss every time.

 

[256bits]

Hi JTG15
Welcome to PF.

Now, I'm sure it wouldn't be enough to actually power the car on its own, but would it be possible as a second energy source, as let's say, a backup, emergency source for electric cars?

If everything was 100% efficient, do you think you would get more energy out than what you put in?
What are drag and friction going to do to the efficiency?

 

[drvrm]

And would it be worth it economically?

this is the major question for such contraptions.

 

[JTG15]

If everything was 100% efficient, do you think you would get more energy out than what you put in?
What are drag and friction going to do to the efficiency?[/QUOTE]

Judging by AverageSupernova's response, I assume the extra electricity generated would be less than the friction/drag it would take to generate the electricity at any speed.

I would think that:

• The added weight of the turbines would reduce the efficiency of the car.
• The wind resistance would reduce the efficiency of the car when accelerating and while it's maintaining a constant speed.

So, overall, I don't think it would be worth it in the end.

 

[xxChrisxx]

If you reduce drag you will also be reducing the power taken from the wind turbine. No wind turbine on a vehicle will ever increase the efficiency or range. It is a net loss every time.

Got to be careful about making sweeping statements. A system can be conceptualized that could yield an overall benefit. OP's statement about putting a system on the inside of the car is part that makes it interesting.

I was thinking, what if the turbines were placed on/inside the grill of the car. Obviously, they'd have to be open to the wind hitting them, but if they were placed on the front of the car instead of on top would this eliminate the drag problem?

In the same way that a cars can control cooling vents. Open when needed, closed when not. You can apply the same thinking to a turbine capture system. (Vent - ducting - turbine.)

Zero drag & zero capture when the prime mover is driving, open and capturing energy when the prime mover isn't driving.

However you have to realize when the system is active it's acting to slow the car. So would only yield a benefit when going down a hill (stealing potential energy from gravity), or when you want to slow down (brakes would otherwise be applied)

It's effectively a really impractical and ineffective regenerative braking system.
EDIT: So much so that I think a real system couldn't exist that gives a measurable benefit.

 

[jrmichler]

The air that flows through the grille and radiator ends up flowing out underneath the car or out through the front wheel wells. That air flow is pure drag. If there is more air flow than needed to cool the engine, one could theoretically extract some energy from it with a turbine.

On the other hand, one can partially block the grille so as to send just enough air through the radiator for cooling. The blocked air flows around the vehicle without creating drag. Some new cars and trucks have active grille shutters behind the grille to do just that. When racers block air flow with duct tape, they call it "speed tape". The reduction in drag will be larger than the energy gained from a turbine because of turbine and generator inefficiency.

The effect is significant. When I added a grille block to my truck, the summer gas mileage improved 5.2% and the winter mileage improved 8.5%.

 

[berkeman]

The effect is significant. When I added a grille block to my truck, the summer gas mileage improved 5.2% and the winter mileage improved 8.5%.

Links? That sounds worthwhile to look into, thanks.

 

[jrmichler]

Links you want, links you get: http://ecomodder.com/forum/showthread.php/modding-06-gmc-canyon-17070.html.

 

[256bits]

The effect is significant. When I added a grille block to my truck, the summer gas mileage improved 5.2% and the winter mileage improved 8.5%.

A piece of cardboard radiator size with a circular hole in the middle foot size or so depending and placed between radiator and grill was used by some folk in winter driving to block off part of the radiator. Probably not so common nowadays as before. It limited the blast of cold air through the radiator and over the engine allowing the operating temperature of coolant and engine to remain higher during operation, and faster warm up turning the automatic choke off sooner, improving gas mileage during the winter than without. Carburatored vehicles at that time. You will see some vehicles such as trucks and semi's with grill covers serving the same purpose. Make sure to remove the cardboard when spring arrives or the engine will surely overheat, and do not sit idling for a length of time for the same reason.

 

[OmCheeto]

Links you want, links you get: http://ecomodder.com/forum/showthread.php/modding-06-gmc-canyon-17070.html.

That is quite awesome!
And it looks like your group has added quite a bit to the "Aerocaps" page since I was there last, 9 years ago.
I only remember Phil Knox’s T-100.
I never did get around to building one.
Though, as I mentioned in another thread; "my daily commute to and from work ... I average 23.4 mph."
So, I doubt it would have made any difference.

 

[jack action]

... then someone throws a wrench in the works and all theory goes out the window (sort of):

​

... even at a small scale (perfect for a high school project):

​

 

[Averagesupernova]

... then someone throws a wrench in the works and all theory goes out the window (sort of):

​

... even at a small scale (perfect for a high school project):

​

I guess I don't see it all that difficult to grasp how a headwind could cause forward motion. Similar to this really:

 

[rokytnji]

Instead of Wind Turbine to generate power with a moving vehicle.
Might wnat to look into flywheel technology instead.

https://en.wikipedia.org/wiki/Flywheel_energy_storage

 

[russ_watters]

Instead of Wind Turbine to generate power with a moving vehicle.
Might wnat to look into flywheel technology instead.

https://en.wikipedia.org/wiki/Flywheel_energy_storage

As the link says, flywheels are an energy *storage* technology, not an energy *generation* technology.

 

[cjl]

... then someone throws a wrench in the works and all theory goes out the window (sort of):

​

... even at a small scale (perfect for a high school project):

​

Nah, that's perfectly in line with theory. You can generate energy with a wind turbine mounted on a moving vehicle if the wind is moving relative to the ground, but you can't just generate energy from the relative wind created by the vehicle's motion.

 

[rokytnji]

Alrighty then. We are talking semantics now?

Arguing semantics to prevent a requested job being done never made much sense to me. The wheels got to turn to turn the wind turbine, The wheels got to turn to get the flywheel to spin < via a reduction gear box assembly >. Wheels got to turn period. Wind turbine don't turn with a parked vehicle. Unless you live in West Texas like I do. And it better be a big top heavy wind turbine fixture at that. On the roof of the vehicle.

I'd run a flywheel any day to make/generate electricity on a car or motorcycle vs a wind turbine any day. I never let some else use of semantics, keep me from getting my idea on how I wish to get something mechanical done. I'd store the electricity in batteries, via from the flywheel spinning hooked up to a added generator/alternator with a voltage regulator, via a reduction gear box or sprockets,chains, and shafts, and then use the spinning stored fly wheel energy to assist the vehicle to keep moving. Even with the engine shut down.

< I know. A lot of commas. Can you tell I was uneducated? >

You can have 2 for the price of one. Without worrying about semantics. If one has the skill set. Walking the walk is more fun than talking the talk. I think that is why Linux developers like me.

Even with my crude ways. See? I have been here with very few posts. Already I am replying to staff mentors.
I mean nothing negative by it. I just have my own way of doing things, is all.
So far. My way get's me by in the Chihuahua type desert we call the Permian Basin.

I pretty much make everything I do from scratch with a bit of shade tree friganeering/figuring.

 

[rokytnji]

Now for the sake of argument. Backup was mentioned. So of course another energy source is needed to spin the wheels.

 

[Baluncore]

rokytnji, welcome to PF.
Before friganeering flywheel storage in vehicles, you should consider the gyroscopic effects which were mentioned in the link you posted.
https://en.wikipedia.org/wiki/Flywheel_energy_storage#Effects_of_angular_momentum_in_vehicles

If you can overcome those vehicle dynamics problems you might have a solution. Since the energy storage will probably need to be coupled electrically to a gimbal mounted flywheel you may do better using batteries than a flywheel for storage. Electric cars already have batteries and regenerative braking, so flywheel storage will be applicable to vehicles fitted only with internal combustion engines.

Anyhow, this thread was about the recovery of waste energy or drag, it was answered in post #2. Understanding the difference between energy storage and energy generation is critically important. As is knowing when it is worth recovering waste energy. Wasting more energy so you can recover more is never an efficient strategy.

 

[rokytnji]

Howdy. Thanks for The Welcome. OK. I'll leave to dead horse alone and go back to what I know.

 

[jack action]

I'd run a flywheel any day to make/generate electricity on a car or motorcycle vs a wind turbine any day.

A flywheel can NOT make/generate energy. You have to, first, put the energy in the flywheel, which has to come from somewhere. The flywheel is the equivalent of a battery in electricity that needs to be «filled» with energy (i.e. charged) before it's used; It is the equivalent of the fuel tank with a combustion engine.

The advantage of the combustion engine is that the fuel can be found in nature ready to be burned; The result of a natural process that took years to happen, but looking to be «free» from our point of view. The wind, the heat from the sun or water running down a stream are also energy that appears to be «free» to us as those actions happen naturally without our intervention.

So unless you find an object that is naturally rotating by itself, a flywheel giving «free» energy doesn't exist. You will always have to put energy in by increasing the flywheel speed, and you will be able to recuperate the exact same amount of energy (less some losses) by slowing it down, nothing more. Hence why it «stores» energy and it doesn't «generate» energy.

So where does the energy stored in your flywheel comes from? If it is connected to the wheels, then it is the engine (i.e. fuel) that will «fill» your flywheel. The only way to do it intelligently is to connect the flywheel to the wheels only when slowing down the vehicle, thus recuperating the vehicle's kinetic energy instead of converting it into wasted heat with the braking system.

Semantics, yes, but different words exist because they identify important distinctions in meaning.

 

[russ_watters]

Alrighty then. We are talking semantics now?

Arguing semantics to prevent a requested job being done never made much sense to me. The wheels got to turn to turn the wind turbine, The wheels got to turn to get the flywheel to spin < via a reduction gear box assembly >. Wheels got to turn period. Wind turbine don't turn with a parked vehicle. Unless you live in West Texas like I do. And it better be a big top heavy wind turbine fixture at that. On the roof of the vehicle.

I'd run a flywheel any day to make/generate electricity on a car or motorcycle vs a wind turbine any day. I never let some else use of semantics, keep me from getting my idea on how I wish to get something mechanical done.

It isn't semantics. The fact that a flywheel is a storage device and not a generation device means there is no net energy output and it therefore does nothing of value for you if "generation" is what you really want. If you want "storage", then we can talk.

I'd store the electricity in batteries...

You want to store storage in more storage? That doesn't make sense: again, a flywheel is a storage medium, so if you have one to use for temporary storage already (like from regenerative braking), you don't need the batteries!

...via from the flywheel spinning hooked up to a added generator/alternator with a voltage regulator, via a reduction gear box or sprockets,chains, and shafts, and then use the spinning stored fly wheel energy to assist the vehicle to keep moving. Even with the engine shut down.

What is making the flywheel spin in the first place? The engine, right? If you use the flywheel instead of batteries in a hybrid car, then you'd have something. There's no net energy generation by the flywheel, but - like with a normal hybrid - it could store energy from the engine generated at higher efficiency to use when the engine would otherwise produce a low efficiency, such as when the car is traveling at low speed.

There are some practical reasons though, why batteries are used and flywheels aren't.

 

[Spacie]

I saw this old thread when looking up the same question. I also came across a paper by a student of a mechanical engineering department of a SA uni that describes how they built a small turbine for a 12v battery. The thing was pretty heavy (25kg, including 12v car battery), but at 120 km/h it produced 2500w. I wonder what you guys think about it. For a quick look see chapter 3.

Design of a Miniature Wind Turbine for Automobiles
https://www.pmu.edu.sa/attachments/academics/pdf/udp/coe/dept/me/design-miniature-wind-turbine.pdf
It appears that the key to their setup was the "nozzle" which funneled the wind for the turbine. Their first setup (a straightforward turbine on top of a car) generated too much drag and so they came up with this "nozzle" solution.

The other problem was that their first choice, a Toyota alternator, required too much torque and so they went with a Delco-Remy alternator which worked out fine.

thoughts?

 

[jack action]

but at 120 km/h it produced 2500w.

But how much drag does it add to the car? (Harvesting more power from the car engine)

 

[berkeman]

I also came across a paper by a student of a mechanical engineering department of a SA uni that describes how they built a small turbine for a 12v battery. The thing was pretty heavy (25kg, including 12v car battery), but at 120 km/h it produced 2500w. I wonder what you guys think about it. For a quick look see chapter 3.

Design of a Miniature Wind Turbine for Automobiles
https://www.pmu.edu.sa/attachments/academics/pdf/udp/coe/dept/me/design-miniature-wind-turbine.pdf

It looks like their "paper" (not published in a peer-reviewed journal, just a paper for their senior project) involved trying to harvest wind energy to charge a vehicle battery when the vehicle is *stationary*, not moving. Obviously doing this while the car is moving is counter-productive, since it takes more fuel to drive the car with the extra drag of the windmill device.

But if you deploy the windmill to harvest wind energy when the vehicle is sitting stationary, then that's a potentially reasonable thing. You would need to stow the device away inside the vehicle before driving it, to keep from adding parasitic drag, and it adds extra weight to the vehicle which affects acceleration and hill climbing performance.

From the "paper":

This project involves the design and manufacture of the wind turbine to be attached on top of an automobile [ to benefit from the harvest power from the wind speed due to height of automobile].
The project is anticipated to help drivers, especially truck drivers to avoid keeping the engine running for long periods of time and utilize energy during idle times. Keeping the engine running will
cause air pollution, waste of fuel, maintenance costs, and environmental noise.
The purpose of the current project is to be able to produce power from a wind source without
compromising the current electromechanical system or efficiency of the vehicle

 

[jack action]

harvest wind energy to charge a vehicle battery when the vehicle is *stationary*

You mean for those days where I'm in presence of a 120 km/h headwind, I will be able to get 2500 W of free power?

 

[anorlunda]

Your project is likely to resemble the wind generators used on many boats.

You could learn a lot from the designs and the specifications of marine wind turbines. For example the one in the picture is reputed to have the highest power output of any brand. There are several brands, claiming 300w up to 2400w rated power. If you find owners manuals for some of them online, look at the spare parts list for ideas such as what kind of generator to use.

Output: 2 amps @ 8 knots, 4 amps @ 10 knots, 10 amps @ 15 knots, 18 amps at 20 knots, 30 amps at 30 knots.

Here are some points, I have learned from boating experience.

• They are most successful in the trade wind latitudes of the globe. In places like the US East Coast, they make almost zero power 4 days of 5, then on the 5th day when the wind blows more, they make 300% of consumption needs.
• They are noisy and the vibration disturbs people's sleep. In your case, it would help to mount it on a pole not mechanically touching the truck cab, or mounting it on the trailer, not the cab.
• Every marine wind turbine owner I know says that they have to learn to be a wind turbine troubleshooter within one year, and a repairman within 2 years. Commercial repairs require mailing it to a national repair center, then waiting 4-6 weeks to get it back. There will be no wind turbine repairmen at truck stops.
• A car alternator is cheap and easy to get, but they do not perform well at lower RPM. With an alternator, I would plan for zero power any time the wind is less than 15 knots (17 mph), in the parking lot. If the parking lot is surrounded by trees, wind is diminished below tree-top height. Boats anchored far from shore don't have that problem.

But heck, this is a student project, not a startup company. Go for it. You'll learn a lot.

Here's one piece of good engineering advice. Step 1 and most important, find out how much power and how much energy per day is required by the trucker. That is the milestone you need to reach to declare success. Do not begin design without those numbers.