Electric Car Blogging

: Photo: General Motors

There’s more to designing a car’s exterior than making it look cool. You have to make it aerodynamic as well. The science of smoothing airflow is of increasing importance as automakers strive to make their cars more fuel-efficient and as batteries play a greater role in propulsion systems.

The earliest experiments in aero design can be traced to the ’20s and ’30s, but it wasn’t until the ’70s that automakers took it seriously. Now most of them develop their cars in wind tunnels. General Motors has the biggest in the industry, and it runs 24/7.

Left: This composite shows what the Chevrolet Volt looks like in the wind tunnel. That isn’t smoke flowing over the car, it’s a stream of propylene glycol. Engineers use it to study airflow over and around vehicles in the wind tunnel.

: Photo: Joe Brown/Wired.com

Abandon hope all ye poor designs that enter here! GM’s tunnel went online in 1980, and these days just about everything the General designs passes this through these doors to be tested. The all-electric EV1 was — and remains — the most aerodynamic production car in history when it emerged from these doors in the early ’90s.

: Photo: Joe Brown/Wired.com

Mission control. Engineers can monitor and record airflow velocity and pressure and their effect on a vehicle’s drag, lift, pitch and yaw. “We’re trying to replicate how a vehicle moves through the air,” says Nina Tortosa, the engineer who guided the Chevrolet Volt through wind tunnel development. “Drag gets the most emphasis because of its impact on fuel efficiency. But 40 percent of our work is on wind noise — making the interior quiet.”

: Photo: Joe Brown/Wired.com

Whatever you do, don’t push the red button! Given the size of the wind tunnel — it’s a closed loop 988 feet long with a volume of two million cubic feet — and its importance in vehicle design, the control panel is remarkably straightforward.

: Photo: Joe Brown/Wired.com

The data display tells engineers everything they need to know about the 43-foot fan at the heart of the wind tunnel. It’s capable of generating wind speeds of 138 mph. Engineers can make as many as 16 runs during a shift.

: Photo: Joe Brown/Wired.com

This platform in the test chamber is where mock-ups — usually clay models — are placed for testing. The turntables allow engineers to move the models to measure their behavior in crosswinds. Testing starts on 1:3 scale models, and changes are made one at a time to see how they affect the rest of the car. “It’s a dynamic system,” Tortosa says. “Make one small change at the back and it completely alters things at the front.” Once the design is perfected in 1:3 scale, it’s transferred to a full-size mockup and the tests begin anew.

: Photo: Joe Brown/Wired.com

The acoustically treated walls of the wind tunnel are a minimum of 18 inches thick. Some 20,000 cubic yards of reinforced concrete were used to build the wind tunnel, which stands on pilings that extend 80 feet into the ground.

: Photo: Joe Brown/Wired.com

Turning vanes in each of the four corners of the wind tunnel manage airflow through the tunnel, which has a maximum height of 48 feet. The vanes are made of acoustically absorptive material to reduce the noise generated by the massive fan as it spins up to 270 rpm.

: Photo: Joe Brown/Wired.com

The flow-conditioning screen at the mouth of the tunnel helps straighten out the air before it flows into the semi-anechoic test chamber. Just prior to the screen, a heat exchanger with 175 aluminum vanes keeps the air at 72 degrees Fahrenheit.

: Photo: Joe Brown/Wired.com

The heart of the beast is a 4,500-horsepower, variable-speed, DC electric motor that turns a six-blade fan at up to 270 rpm.

: Photo: Joe Brown/Wired.com

The fan has six blades, each weighing one ton. They’re 12 feet tall and made of laminated Sitka spruce, which was selected for its high strength-to-weight ratio. With the motor spinning at maximum velocity, the tip speed of the blades is 415 mph.

: Photo: Joe Brown/Wired.com

GM’s Nina Tortosa, with her favorite colleague: the fan.

President Bush signed a spending bill Tuesday that includes billion in low-cost government loans for the auto industry. The idea is to allow automakers to borrow money in order retool plants to build more advanced technology vehicles—including hybrids, plug-in hybrids, and clean diesel cars—to boost fuel efficiency by 25 percent.

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Nine Tesla employees stormed Seattle last weekend on a four-day sales and marketing blitz. The trip was a great success – not only for 80 customers and media who got to drive the car but for those of us at Tesla scouting the perfect location for a Seattle-area store, which we are planning to open [...]

Filed under: EV/Plug-in, Hybrid, MPG, Audi, Paris Motor Show

Audi has released the official details on its new A1 Sportback concept that debuts at the Paris Motor Show. At 13.09 ft long, the A1 is a couple of inches longer than a MINI Clubman and features a hybrid drivetrain. Power comes from a 150 hp TFSI four cylinder with turbocharging and direct injection. The engine’s output is blended with the output of a 20 kW, 111 lb-ft electric motor and sent through a 6-speed dual clutch S Tronic transmission. The electric motor is sandwiched between the engine and transmission and can provide electric boost as well as electric only drive at low speeds. The lithium ion battery pack has plug-in capability and is claimed to be able to propel the car for 62 miles in electric only mode. The car can acclerate from 0-100 kph in 7.9 seconds and still get 60.3 mpg (U.S.). Carbon dioxide emissions are a mere 92 g/km.

[Source: Audi]

Continue reading Paris 2008: Officially, official Audi A1 Sportback concept

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Filed under: EV/Plug-in, Africa, Paris Motor Show

The first images of the Joule from Optimal Energy have now turned up on the interwebs. The Joule will be officially unveiled this week in Paris at the Motor Show. The six-seat hatchback stores energy in a lithium ion battery pack that can nominally propel it for about 120 miles. A second pack can be added that doubles the range. The plan is to eventually offer packs from a number of suppliers with different characteristics. This would allow drivers to opt for longer range or more performance. South Africa-based Optimal Energy is still looking for a site for its factory and the city of Gauteng is said to be in the lead. The car is expected to be available toward the end of 2010. Thanks to Matt for the tip!

[Source: CarToday]

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Filed under: EV/Plug-in, Green Culture, Green Daily

Great Scott! An all-electric 1981 DeLorean DMC-12 is now up on eBay for the bargain price of ,600. Well, it’d be a bargain if it could jump through time and wasn’t under the reserve price. The one-off conversion was done by the seller and a friend and uses a WarP 9 electric motor that gets juice from thirteen 12 volt 100 amp-hour deep cycle Deka 9A31 Intimidator AGM batteries (they take up the trunk and underhood spaces. These can power the car for a 40-mile range and recharge in eight hours from a standard wall plug or 2-3 hours from a 220-volt outlet. The seller has put a series of videos about the car up on YouTube, including “Shifting gears in a clutchless Electric DeLorean,” which we’ve pasted after the jump. Drawbacks to the home conversion are that the heater and A/C have been disconnected.

The seller promises that “If the Buy It Now option is used, I will include the custom build “Flux Capacitor” shown in the pictures.” That BIN price is a cool 0,000, so you might just want to save your pennies for a Mr. Fusion. H/t to Mike for the tip.

[Source: eBay]

Continue reading Do not drive over 88 mph: all-electric DeLorean for sale on eBay

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Filed under: EV/Plug-in, Hybrid, Chevrolet, GM

There has been a fair bit of discussion and controversy in the last couple of weeks on the interwebs about the exact nature of the powerflow and battery charging in the Chevy Volt. Back in July GM’s Larry Nitz discussed how the charge sustaining mode would work. As with parallel hybrids the battery is generally kept between about 35 and 85 percent charge. That means when the battery reaches its “depletion” point it still has a significant amount of charge left. The range extender has less power output than the the electric drive motor is capable of (100 hp vs 150 hp) but it has enough output to work in most day-to-day driving conditions. The range extender doesn’t normally try to charge the battery fully as that is deemed to be less efficient and more costly than holding the battery at the minimum until the car can be plugged in. For the times when more power is needed such as acceleration or hill climbing some of the reserve battery power is available to be used. The battery can be drawn down below the “depletion” point to about 25-30 percent. When this happens, a combination of regenerative braking and some surplus power from the range extender will bring the battery back up to the minimum. A video after the jump shows the various modes and the power flow.

[Source: General Motors]

Continue reading VIDEO: Animation showing the power flow in the Chevy Volt

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Filed under: EV/Plug-in, GM, AutoblogGreen Exclusive, Green Daily, Automotive X-Prize

The Progressive Auto X Prize has gotten over 100 teams that have expressed an interest in competing in next year’s competition. While a lot of these teams are small groups with big dreams, the X Prize foundation has repeatedly said they’d like the OEMs to enter. Early this year, the X Prize approached major automakers but they declined to participate.

Now, with the Chevy Volt, we have a vehicle that might get a 100 mpg rating from the feds. While the government’s rating is not what the X Prize will be using to determine their MPGe numbers, we got to thinking: what if GM enters the Volt into the X Prize? It seems like a good publicity move, but would the General entering the competition be like Goliath crashing David’s birthday party? Would the Volt even have a shot at winning, in your view? Also, there is a risk here, a big risk: what if the Volt were to lose to a high school team, how would that make GM look?

So, that leave us with the original question. Whaddya think?

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