Smell of Diesel in the Morning

What happens when you put sixteen men in a house after asking them not to have drank alcohol for the last 24 hours and no smoking or caffeine in the last 4 hours. No this isn't the next reality TV show. One at a time and every two weeks subjects underwent two hours of testing with a stationary bike in a chamber that may or may not have been pumping diesel engine exhaust fumes into the room with them. 10% of the exhaust gas from a 2.2L diesel engine was diluted with air and fed into the room in such a way that there was a 300 μg/m^3 concentration which is supposedly similar to high traffic areas or especially congested and polluted cities. In another configuration they passed this concentration through a teflon filter and in another they had a concentration of carbon nanoparticles.

It's no secret diesel technology is of great interest to me. Over at Engineer Blogs one of my earliest posts was on the Military's Love Affair with Diesel. I also just talked a few days about how the Chevy Cruze might have a diesel version coming to America. So it's interesting to see where we go forward as we worry about emissions and cardiovascular health. Also what kind of technology might move us forward in the direction we want.

When the research team filtered the exhaust gas they ended up with a much lower concentration. Their exhaust gas averaged 348 μg/m^3 and regular, filtered air was less than 1 but the filtered exhaust averaged 6.

So what's the end result? Well a lot of things were, perhaps surprisingly, not affected by the fumes. No difference in resting heart rate or blood flow. Systolic blood pressure took a hit up, but diastolic did not. What their carbon-only concentration was useful for is that it could be it's not the parts of diesel exhaust that we need be concerned about but something about the whole. Something that's happening in combustion might be making these nanoparticles more harmful.

Their conclusion is this: diesel exhaust fumes in the concentration tested impaired vasomotor vascular function. Filtered exhaust and the carbon nanoparticles did not affect vascular function. What they showed is a filter than can reduce concentration effectively can make a big difference. But they admit at the end that these kinds of filters are pricey and not applicable to a lot of commercial applications where those filters would have to be tested separately. Being an engineer, I keep thinking about the engine sitting in another room idling for two hours. Still the implications for design work on reducing the environmental impact of diesel exhaust is there. And there's the lesson that individual pollutants can't always be used to draw conclusions from as it's important to test the whole system and see what a difference that makes. The combustion was obviously a key factor in making this combination of elements dangerous, and possibly more dangerous than the sum of its parts.

Mills, N., Miller, M., Lucking, A., Beveridge, J., Flint, L., Boere, A., Fokkens, P., Boon, N., Sandstrom, T., Blomberg, A., Duffin, R., Donaldson, K., Hadoke, P., Cassee, F., & Newby, D. (2011). Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation European Heart Journal DOI: 10.1093/eurheartj/ehr195

In Development: Detroit Diesel

So far American car manufacturers have been hesitant to adopt diesel for small cars. That might start to change as technology for clean diesel improves, the US continues to set high fleet standards for MPG, and the efficiency of diesel can sometimes far outdo that of petrol.

GM is planning to bring diesel into the US by having a diesel version of it's Chevrolet Cruze. It's rumored to be capable of 50 MPG and might hit showrooms in 2013.

Future Engineers

A couple of links for easy weekend reading.
A summer camp in San Jose teaching kids hands on civil engineering skills.
Will there some day be a 5-stroke petrol combustion engine that does better than a diesel engine?
Bob Gower CEO of United Memories gives a tour of the place that does chip testing for the semiconductor industry right in Colorado Springs before he retires. They gloss lightly over outsourcing, the quality of US engineers, and the worth of keeping jobs here.

Design Fridays: Volvo's new flywheel

Volvo's claiming their new flywheel design will be able to give a four cylinder the equivalent of six cylinder power as well as save 20% of combustion energy.

 

A flywheel is just a name for a rotational device that's able to store energy. It does this by using inertia and saving rotational energy. The amount of energy that can be stored is based on the moment of inertia and rotational speed, where moment of inertia is based on mass and radius of the wheel. Typical flywheel designs might include differing weights at certain points in the wheel that help keep the rotational speed more consistent and higher.

 

In your typical automotive application, a flywheel sits on the end of your crankshaft and converts the energy and movement of the crankshaft into a more consistent rotational speed.

 

Volvo is claiming that their flywheel will be able to store so much energy that when the engine is idling it can actually turn off and the energy stored in the wheel is enough to start combustion again. If so that could explain their 20% fuel savings number as engine idling is a well known waster of energy (why electrical cars and the Prius shut off at a stop). The flywheel also sounds like it is using aspects popular in hybrids and electric cars: regenerative braking. There've been a lot of attempts to incorporate regenerative braking into designs, the idea that you can get back part of the energy you're wasting to brake. But generally these designs haven't been efficient enough to be practical (plus once you add complications, you add more room for failure, and the more components the heavier your car thus reducing your energy savings).

 

They're supposed to start field testing this sometime later this year.

Design Fridays: Engine Runs on your Dreams

Cyclone Power is developing the Mark V engine and claiming it can run on "almost any fuel." In actuality it looks a little like a lawnmower engine in size. In principle it runs off a rankine cycle or regenerative heat cycle or, they claim, a Schoell Cycle named after the inventor who originally developed the cyclone engine. Rankine follows a four step process:

• 1 ->2 Fluid in liquid stage pumped to high pressure
• 2 ->3 Heated at constant pressure, becomes a saturated vapor
• 3 ->4 Vapor goes through a turbine, generates power
• 4 ->1 Vapor enters a condenser and becomes a saturated liquid

I'm a bit skeptical as to their claim of this being anything "new" or being able to run on "any fuel." I talked a bit on Engineer Blogs about diesel and the way a compression ignition engine versus a spark ignition engine functions are pretty different. Just because their engine might have some flexibility does not mean it wouldn't lose a lot of its efficiency depending on what the working fluid is. They're claiming they can use algae or waste oil as fuel but honestly this is nothing new. Most diesel engines can be easily (or fairly easily given you have time and know what you're doing and have a little money for parts) modified to run on many other kinds of fuel. That's the whole point of biofuel, it runs in engines we've already designed and are using. Especially in large vehicles and trucks which still account for a huge percentage of our transportation costs for shipping product in this country.

 

Getting all that aside, I do think it's interesting. You don't see a whole lot of radial engines these days. Combining it with a rankine-type cycle and focusing on growing demand for biofuel power generation devices is probably pretty prescient. But there's reasons we don't use external combustion engines in our cars or airplanes so we need to keep looking for practical solutions for that fit our society for both cost and environmental reasons. And maybe something like this can be a part of it.

 

I think hydrogen engines are promising (maybe that's a whole future post?) and while small, solar powered stations might work for individual's cars it won't serve as a substitute for the whole power structure. Clearly we need diversity in our power solutions and maybe this clever little engine can be a part of that.

Cold Weather and Hard Facts

It's time for some cold weather driving. Break out your snow tires, flip on your AWD, and remember to steer into the spin. The Canton Daily Ledger answers several car myths about oil changes, work from the dealership, and even washing your car with dishwashing soap. However, my favorite is this cold weather classic:

- Myth: My car engine needs to warm up before driving.

During winter months, it is a common practice for drivers to warm their vehicles up inside, but a cold engine will warm up faster when it is being driven instead of idling. If you use your car infrequently, take a few minutes to warm up your car before you drive away. This allows cold, thick oil to warm up, protecting your engine from damage. For cold weather starts, all you need is 30 seconds to ensure proper oil flow and lubrication. In the event of frigid temperatures, driving at a slower speed for a few miles will give your car enough time to warm up.

I'm not saying we trust all our car advice to some yahoo who lives in Illinois (Junior Damato, the Talking Cars columnist) but I wish my neighbors would read his advice. Because I'm sick of hearing their "pimped out", muffler tuned little POS car idling and being revved up for 30-40 minutes every night usually while I'm trying to enjoy dinner or even better while I'm trying to sleep. It doesn't even sound like a proper car. It sounds like someone's mowing their lawn, but then irritatingly revving their lawnmower, and of course it's obnoxious noise is also likely tuned to carry some distance so it's a really loud lawnmower.

It's great they take their car seriously, and it appears they race other vehicles of theirs (which must be how they pay the mortgage since none of them ever seem to leave to go to work, coke dealer also comes to mind). I'm not a specifically automotive engineer, but it's my understanding engine idle is one of the most wearing portions of an engine's life. An engine wants to be in cruise speed. It does make me wonder why so many aircraft engines require such extensive warm-up periods in comparison, but honestly it doesn't get that cold where I'm at, and they don't even drive it anywhere afterwards. Automative engines are pretty hardy stuff. So stop idling your lawnmower all night. Thanks.

Great Risk, Great Responsibility

Almost twelve years ago NASA launched the Deep Space 1 Probe. The first interplanetary device to demonstrate successful ion propulsion in space. Ion engines were by no means new. In fact, they are the given explanation for how the Star Trek shuttlecraft are powered in the original series. The idea is to use electric power to accelerate ions, something only possible in an engine in the vacuum of space. What results is a much higher specific impulse, a measure used to define the efficiency of chemical propelled rockets. The more impulse per mass of propellant used, the more efficient the propulsion.

 

The ion propulsion system is what specifically gave DS1 its efficiency, allowing it to travel at the same speed for about half the mass of conventional space propulsion. However, its launch was not without problems. On board it carried a multitude of different payload devices, most of which had never been tested in space. The engine also failed soon after it first started though they were able to restart it successfully and the engine continued thrust for almost two years.

 

As someone who has dealt with aircraft payload devices as well as engine hiccups its hard to imagine what this is like. Of course you do as much software simulation and ground testing as possible, but if the conditions at high altitude are different enough from those at ground, I'm sure there's magnitudes of difference between ground and lab testing versus space. Then how do you troubleshoot? There are some serious advantages to being able to take pieces of your hardware and inspect them or replace them. The advantages of being able to look everything over visually, then pull things apart. Your satellite likely doesn't even have an arm or anything you could use on itself. At least a deep sea robot device you could potentially get it to surface in order to work on it, but your satellite or space probe is never coming back.

 

Seems like the pure basics of exploration. Before humans went out in ships or on trade missions early tribes moved and explored mostly when they needed to migrate. When food or resources were scarce they journied on, not knowing what lay ahead only to find new places to survive, how they theorize Easter Island was originally settled. Technology gives us the advantage of not risking human life in many of these endeavors, but the payoff is still enormous.

 

Since DS1 numerous other devices have employed ion propulsion in space. It will be interesting to see how far this technology will take us; physically, and to what limits of our dreams.

 

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Happy Horsepower

Fiat is making a 57 mpg car from a TwinAir engine. It will be a two cylinder with up to 110 hp for the turbo version, or as little as 65 hp. That might be more than you need given how small the car looks. Wired is speculating on whether this will be introduced in the US. I sincerely doubt it, though it's possible work on this engine may lead to introduction to other smaller, more fuel efficient engines from Fiat in the future.

 

GM is upping their game by letting Corvette buyers assemble their own engine (for a price of course). They're charging $5,800 for it which is pennies compared to the price of the Z06 or ZR1 engine. If I were a Corvette buyer (and had that kind of cash laying around) I'd definitely take them up on this. How neat for the engine enthusiast but non-expert.

BBQ Tips and Quickies

Ok this has nothing to do with BBQ. In an effort to jump on the 4th of July holiday bandwagon a few people are misunderstanding the spirit of summer. First, Paul La Monica of CNN Money says our recovery will be a "BBQ Recovery: Low and slow". Haha, I get my kicks from timely summertime headlines.

In other more explodey news, some coolant company decided to melt an engine block in an effort to advertise their coolant. It's cute because it's on a grill. Get it, summertime, grillin? No? Well just look at the burning and then buy some coolant. Personally I prefer my engines more on the rare side.