Why do a grill block when you could put excess air to good use?

[ChazInMT]

ConnClark putting something in an airstream will be a less efficient way to do something. Period. You even admit it when you say "No" to "will you get something for nothing."

And, where do you get the idea that a turbine in the grill is a block? It is a huge flow restriction. The air comes in, gets massively slowed down due to having given up its energy to the turbine blades, and exits the back. A turbine is like a Cd 1.5 element on the car. The air does not see the turbine and decide, "Hey, maybe I'll just go over the hood instead", it eats all the air that hits it. A grill block makes the air go over the .32 Cd part of the car instead of through the 1.1 Cd part in the engine bay. Does this basic concept make sense to you? The Turbine is NOT a block. It would be a huge drag for its size no matter where you put it. Something that forces air up and over the roof of a car (solid grill block) is not a drag, it helps eliminate drag.

Lets review, Turbine in slipstream: Adds Drag. Something that diverts air from a high drag area to a low drag area: Reduces Drag.

Now, I'm sorry that the "Rant" portion of my dialog contained too much technical information for you to understand, power generation efficiencies and all, but the facts included in my “Rant” say why your idea, while creative, is doomed by science to never work. Same reason why you can't just grab your own feet and pick yourself up of the ground, it's all there in the "Rant".

If you want to come up with efficiency numbers and show how I'm somehow mistaken in my reasoning, feel free to do so. But please for the sake of not looking like you really have no concept of the basics, include some numbers and diagrams with your idea, not just a bunch of “I swear I think it works” statements, cause heretofore, that’s really all you’ve given.

Now the NASA Link
Capturing energy from a vortex forming element on an airplane, such as the NASA thing, is entirely different than what you are proposing. NASA doesn’t want to put a generator in the inlet of an engine, or anywhere else for that matter in the slipstream. They want it in a very specific place to try and capture the energy used in vortex formation and put that to use.

Now, if you want to propose putting some sort of generation device behind the C-pillar on a car to capture the same energy that goes to waste generating vortices there, that is a different story, by eliminating a vortex, you will gain a potential amount of improvement in the Cd of the car which could be used to make electricity. I'd say that‘s a good idea. But, good luck engineering it. That’s a completely different proposal then putting a high drag element on a car in front of a medium drag element and hoping to save gas.

You do want to save gas right??? I mean, again, I’m not saying you won’t generate electricity and use it somehow with your proposed device. I’m just saying you’d get like 33 mpg with it, and 35 mpg without it YMMVBISAHWI. (Your mileage may vary but it sure as heck won't improve)

[ConnClark]

Originally Posted by Daox

2) The turbine may marginally reduce the energy required to cut through the air (overspill around the turbine like the grill block). At the same time, it will create drag by taking the air that passes through it and generate electricity at a pretty horrible efficiency. I think most windmills are ~30%. I doubt this is any better. Keep in mind that you've already spent energy to get your vehicle up to speed with an inefficient ICE (~30% efficient), so you have those losses on top of it. Air that has passed through the turbine will have very little pressure left and therefore is of little use for cooling since you need a pressure differential across the radiator to get flow.

Well not all the air will flow through the turbine some will go around the sides unless you duct every thing through it. Also a turbine isn't going to extract all the energy from the air. The total pressure will be distributed across the turbine and the radiator.

It will be like two resistors in series in an electrical circuit. The pressure across each one will be enough to get the same volume of air through each one just like the voltage will split across the two resistors and each voltage will be sufficient to get the same amount of current through each of them. The two pressures differences added together will equal the total pressure available just like the sum of the voltage drops will equal the total voltage.

make sense?

You may not get a lot back but you will get something back maybe 3 amps or so. That would be about 1/10th of a HP savings driving the alternator. Plus you would reduce net drag on the car.

[Cd]

The idea reminds me of this : Fuel saving device for increasing ... - Google Patents

Popular Science also had a small write up on a van that had a roof mounted fan connected to a generator . As the blades turned, they would fold back to reduce drag.

I can't find the article now. It's was around 1999 and had a main feature titled " Detroits new 80 MPG cars. The cars were the Ford Prodigy, the dodge ex3 and the GM Precept.

[NeilBlanchard]

No matter where the wind turbine is located, if the air flow spins the blades, it will add drag to the vehicle. There is no free lunch.

Remember, drag *through* the radiator and the engine bay account for about 10% of the overall drag. If you add drag to this "path" then you add drag to the vehicle.

This thread needs to be move to the Unicorn Corral.

[ConnClark]

Originally Posted by NeilBlanchard

No matter where the wind turbine is located, if the air flow spins the blades, it will add drag to the vehicle. There is no free lunch.

Remember, drag *through* the radiator and the engine bay account for about 10% of the overall drag. If you add drag to this "path" then you add drag to the vehicle.

So your saying grill blocks don't work?



Looks like its adding drag to the "path" through the engine bay to me.
As stated before this isn't a free lunch. You have already paid for it.

[CigaR007]

Grille blocks aid in reducing the airflow entering the engine bay. That means less drag internally (related to cooling) by deviating the incoming flow to the sides and upwards of the hood.

A turbine upfront is not ideal; far from it.

[ChazInMT]

OK ConnClark, I've reconsidered everything and By Golly, You Are Right!!!!!!

You need to apply for a patent on this, invest a few million dollars in production and start making these things RIGHT AWAY!!!!

In a few years, we'll read about you in Fortune Magazine, where you'll do an interview from your Yacht, and we'll think, "How stupid were we to ever doubt such a keen intellect!"

So as not to distract you from your busy venture ahead, I vow never to reply to anything you ever write in here again. I really hope you can put out of your mind all the doubt I may have cast on whether the "Grill TurboGen" was a viable idea or not.

Good Luck!!

Charlie

[mcrews]

ok.

can't believe this went 4 rounds.....err pages.

I'm w/ charlie. Call us when your name is in lights......

As a note: JBA headers are an aftermarket header for 5liter ford V8. mainly mustangs.
Jay Bittle of JBA (automotive) went to Texas A&M at the same time I was there in the late 70's. Had a 68 Shelby GT500.....original. Was into to racing etc.
Today JBA is a BIG name in Mustang aftermarket stuff.

Just sayin........

[NeilBlanchard]

A turbine is not a grill block. It would add to the drag; not reduce it like a grill block.

The laws of physics apply everywhere -- inside the engine bay as well as outside. So, the added drag of the turbine would be a net loss of energy.

[aerohead]

Originally Posted by ConnClark

Stick one of these in front of or behind your grill and you will get the same effect as a partial grill block and some energy back to boot.


BPE14 TURBO STAND-BY ALTERNATOR from Aircraft Spruce

Sounds like a good idea but would it be really?

It violates every tenant of streamlining.And I believe that they are only used in emergencies to power instruments necessary for IFR landings.