AirFlow BulletTruck Project (aerodynamic, modified Class 8 transport doubles MPG)

[Galane]

Originally Posted by ACEV

A lot of people forget that a little torque can be multiplied by lower gearing. Also, a tractor/trailer used for city delivery over an eight hour work day will spend over six hours only needing 100 hp and 200 hp for approximately one hour total.

Doesn't work for long haul trucks. They need to go at least 55 MPH, and maintain that speed even going up hills, unless they're hauling very heavy/oversize loads.

[Shepherd777]

Originally Posted by ACEV

A lot of people forget that a little torque can be multiplied by lower gearing. Also, a tractor/trailer used for city delivery over an eight hour work day will spend over six hours only needing 100 hp and 200 hp for approximately one hour total.

Originally Posted by Galane

Doesn't work for long haul trucks. They need to go at least 55 MPH, and maintain that speed even going up hills, unless they're hauling very heavy/oversize loads.

What ACEV is advocating will absolutely work for long haul trucks.

I believe you are thinking about a conventionally powered rig. One with a large ICE, a transmission, and a differential, or two.

That has no relation to a series hybrid configuration in this discussion. It is an apples to oranges thing.

We are venturing way off aerodynamics in this post. I am thinking about starting a new big-rig discussion in the Hybrid Forum.

[Blue Angel]

Originally Posted by Shepherd777

We are venturing way off aerodynamics in this post. I am thinking about starting a new big-rig discussion in the Hybrid Forum.

I'll be watching!

[p38fln]

That's awesome! We've started getting trucks with single differentials here instead of the double differentials that have been common for the last 50 years or so (They're 6x2, most trucks are 6x4 drive). There are also collapsible trailer tails on the trailers and side skirts.

For what it's worth, the highest I ever managed to get a semi on MPG was 9.02 MPG with an empty flatbed headed from Chicago to Duluth.

[Blue Angel]

Funny wind tunnel video, actually demonstrating airflow over a horizontal hood and vertical windshield (similar to many heavy trucks). And the human face...

http://www.youtube.com/watch?v=hmYC9...endscreen&NR=1

Not too scientific (the camera man is actually standing upstream at the start of the video...) but funny anyway.

[Blue Angel]

And this video shows what is likely a key reason for the lack of truck aerodynamic study; no wind tunnels large enough for full scale tests! Here, a rig is tested in a NASA wind tunnel... I don't imagine this facility is cheap to rent:

http://www.youtube.com/watch?v=uE_0VUL6B08

[Efe]

Originally Posted by Shepherd777

What ACEV is advocating will absolutely work for long haul trucks.

I believe you are thinking about a conventionally powered rig. One with a large ICE, a transmission, and a differential, or two.

That has no relation to a series hybrid configuration in this discussion. It is an apples to oranges thing.

We are venturing way off aerodynamics in this post. I am thinking about starting a new big-rig discussion in the Hybrid Forum.

Shepherd777 R u familiar or involved with epower engine systems? It seems like the design you are advocating is exactly what this company is developing. You can see their prototype unit running on youtube. Can u elaborate? If you are not part of their team you should look up to join them somehow? They might need your efficient aero designs and experience to improve their mileage.
By the way I admire your hard work and amazing designs you have created very much so far. You are a great trailblazer that sets the example for the whole industry. I wish I had the resources to underwrite your projects and 49 page business plan. May be some day when your company goes public you can tip us to buy some shares.

[Xist]

Originally Posted by Shepherd777

20+ mpg, actually. Remember big rigs do like 95% highway driving. And around town, the batteries and super-capacitors will be doing the work.

What am I supposed to do when you can move 80,000 pounds with less fuel than I need for 3,000?

[seifrob]

I know this should go into hybrid forum, but I cant resist. I am little sceptical about all the hybrid power extasy. From this page: EPower Engine Systems; Exploring The Limits Of Hybrid Truck Efficiency - John Petersen - Seeking Alpha it seems that the biggest advantage in hybrid over traditional power is that engine runs under constant load at ideal RPMs. Something Shepherd777 can achieve with his 13 speed manual too.
Allright, there is regenerative braking. And fuel cut off in deceleration.

So here is my question. Is hybrid really so much better over decent "traditionally" designed drivetrain and driving with brain, so it is worth the increased overall complexity, need to change whole battery pack every 5 years, need for specialized service, risk of being underpowered when in emergency and so on? I am just curious.


I assume that due nature of hybrid running in constant RPMs even a trigger happy heavy footed driver gets good mileage. How about robotised stick-shift that keeps motor in ideal RPMs but takes a load off the driver, still enabling him to choose the gear manually? (something like this: http://www.tatratrucks.com/underwood...norgren_en.pdf)

[Flakbadger]

You bring up some fantastic points (that I would also like to hear the answer to), but this:

Originally Posted by seifrob

How about robotised stick-shift that keeps motor in ideal RPMs but takes a load off the driver [...]

just makes me think: "Isn't that called a CVT?"