A straight and simple review

This is my attempt in trying to review things that seem to get a lot of attention - especially in the engineering world. Not necessarily bad reviews, more like constructive criticism. I provide reasons why I make the claims and make equivocal arguments. I typically pick topics that I have a background in, or have gathered a lot of information. 2 articles a week is my goal - will keep it that way .

Saturday, June 03, 2006

Traffic Congestion : Slow Down

At last, a topic I know something about. We all know air traffic is a tricky thing. There are a lot of statistics that show how much money is lost because of traffic congestion etc. The main area where air traffic congestion originates is the airport zone. Around the airport is where the congestion is maximum. This figure shows the area around Chicago O’Hare.

Where the congestion is high, the probability of collision is high (no rocket science). So, to avoid this, my friend had a research proposal. The main reason for this congestion is because planes tend to slow down near the airport – as they wait for gates to open in the airport, or until the run way clears up. Her study was trying to reduce the delay in the area immediately surrounding the airport.

This figure shows a conceptual idea. Zone 1 surrounds the airport – the delay here is maximum, and so is the congestion. From Zone 2 to 5, the congestion reduces. Zone 5 is the cruise zone – there is almost no delay here. The plane’s velocity (cruise speed) is about 0.75- 0.79 Mach. This is the best velocity as it consumes minimum fuel for commercial aircrafts. So, when these planes are made to slow down in Zone 1, the airlines don’t like that – it consumes more fuel - it costs a lot of money.

This research tried to reduce the delay in the red zone, by splitting the delay to all the other zones (?) Let me explain. Lets say for a journey from A to B, the delay expected near the airport is 10 minutes. Rather than spending 10 minutes in the Red zone (which is what happens now), it was suggested the 10 minutes be split up and distributed in all the 5 zones.

Lets say, you decide to slow down in Zone 5, then the cruise speed will reduce from 0.79 to say 0.75. As mentioned earlier - around 0.75 Mach is good cruise speed - the drag is minimum and hence fuel needed is also minimum. So now, the time spent in the red zone is reduced - which is the objective of the research study. Currently - the system works differently. In the red zone, when the planes circle as they await a spot to land, the speed is about 0.4 Mach. This is a lot slower and basically consumes a lot more fuel. Airlines don't like this - as they have to blow a lot of money doing nothing - just for waiting around. They would much rather slow down to 0.75 M in Zone 5.

The risk here is this – lets say it has been calculated that the delay is 10 minutes and 8 minutes of those have been split in to Zone 2,3,4, and 5. Only 2 minutes remains to be burnt in the red zone. But for some unexpected reason there is further delay of about 8 minutes in the red zone. Then what has happened is your total delay is 20 minutes – which might have been avoided if this new algorithm wasn’t implemented.

A lot of work remains to be done in this area – but I hope you get the picture. The idea is that by fully utilizing Zone 5 (which is very vast), congestion can be minimized in Zone 1. This is good for every one – the passengers reach destination on time; the airlines waste less time and spend less fuel; the air space is a bit safer due to reduced congestion. Well the challenge of course is implementing the system in a national scale. There are lot of studies being conducted, just to see if this system will really help. There have been many such ideas which have been rejected as they actually seem to make it more complex; but NOT THAT 1 - this system I think, will be implemented in the near future.

Pretty dry blog actually – sorry about that ! My interest in this area is mainly triggered by one of my professor Dr Eric Feron in Georgia Tech - Aerospace. His research is in this area and he is considered an "expert" in it. He is a prof from MIT and recently moved to GT. I don't think he will be my guide - definitely wouldn't mind though.

Thursday, June 01, 2006

Bridging the gap

S'il vous plaît

OK - no one I know of, is a fan of France. I love Wines and French Vanilla, but those are the TOP French products. In the world of engineering, we might think of 2 achievements – The Airbus (which is a conglomerate with UK) and Renault – which is an awesome car company. I guess, there is something that I over looked in this country.


Millau is a town in Southern France – not famous for anything. It has an insect museum and a glove museum (really) , and then there is paragliding. Although, it is famous for traffic jams. Near Millau , there is this lovely valley and all automobiles have to go down this valley and come back up to travel to Millau. To avoid that, the government built this bridge. More over, this valley is a preserved area or something – which means the govt. is happy to build a bridge to divert the traffic.


Viaduct is I think French (or European – they use it everywhere) for a channel or a tunnel through a valley. This is somewhat a flawed usage – they tried to make it resemble aquaduct – which is a common expression for water tunnel. This is the highest bridge in the world and definitely a piece of wonder. It is a smart bridge – raises and dips up to 10 meters depending on the weather. It took I think about 4-5 years to build it – which is fast. Click on this link http://mywebsite.bigpond.com/johndeutscher/Ian/Photos/Millau_Bridge/

to see photos of different construction stages (a must see for engineers) . I am going to skip the technical mumbo jumbo. Its taller than the Eiffel Tower and about 4 kms long I think – that’s all the numbers. The pictures explain the construction better than I can. Its called a cable-stayed bridge- as opposed to a suspension bridge.

Bridging a generation gap

We all know bridges are wonderful engineering. The truth is, we haven’t seen a brilliant bridge in a long time. Most bridges we know of, are many years old – London, San Francisco Golden Gate etc. I mean, they have always been there, they are nice but nothing ‘break-through’ about them.

The Millau Viaduct is about a year old now – its truly a new bridge. It makes use of modern technology and innovative methods. Everything from the concrete used, to the cranes you see in the picture in the link are things that didn’t exist 10 years ago. More over, this bridge is a piece of architecture – not just engineering. There was a British architect who designed it – and the engineers enforced it. Look at the shape in the top view. Also, the rise and dip principle is a new concept (Also being used in Japan).

I think this bridge has truly bridge a gap in the generations of technology and engineering. There are not too many bridges that can boast this true wonder (Oresund can – will write about that in a later blog). More over, what makes this truly remarkable is the fact that it was constructed in a valley in almost no where. It didn’t link big cities or popular tourist destinations. The French govt. was surprisingly sensible enough to approve such a project in such a remote place, just so that they can have a super structure. They could have made it much low lying with RSJs; used suspension cables or utilize struts – but no. They actually pulled off a huge cable stayed bridge. They collect I think about 10 Euros as toll and reduced for frequent usage – but if this was some where near Toulouse or Paris, I am sure they would make much much more money,

So I guess, more than the world-record height; the 100-year warranty; minimum maintenance design; the real achievement here is the investments in a modern engineering wonder. It reaffirms strength in engineering – rather than computers and software and spacecrafts….and most surprisingly , it has been developed in the middle of no where in France. A lot of things suck in France, but NOT THAT 1.

(Photo Credit : http://viaduc.midilibre.com/)

Monday, May 29, 2006

Prius the Lord

The Toyota Legacy

Toyota is good auto company. They make good engines primarily; hence all cars that carry these engines seem to work very well. Another achievement is the cost – Toyotas are relatively inexpensive, cars costing mostly in the range of 12,000$ - 35,000$. The SUVs , Trucks and mini vans uphold this reputation as well. The Toyota Hi-Lux (a variation is Tacoma in USA) is one of the toughest trucks in the world as shown in an episode of Top Gear (BBC UK). The new FJ Cruiser is a 2001 concept car that was successfully converted to road vehicle.

…and this happened

The Prius is probably Toyota’s worst piece of engineering. This is a science project converted to a road vehicle. At a cost of more than 22,000 $ , the Prius uses 2 engines – a 76hp 1.5l DOHC gasoline and a 67hp 500v electric engine. Having two engines clearly boosts the cost ( ..a lot) + the added intelligent technology of switching between the engines. Hence, Toyota has decided the cut corners in all the other parts in the Prius.
The engine is a no brainer – very low power. The acceleration, 0-60 mph time is 12 seconds and a top speed of 99 mph only. Let me not pick on that – too easy. Lets look at some other features that make the Prius , a toy.

(-) Rear suspension – nothing there , so makes the drive feel like an amusement park ride.
(-) The interiors are cheap recycled ultra light plastic – somewhat like Nilkamal chairs. Nothing in the interior makes you feel specifically majestic, looks just like every other Japanese interior. One special feature though – a screen that provides data about performance of the hybrid data. A Hybrid 101 sort, with a lot of graphics and sounds and color - an entertainment piece basically. Ofcouse, a definite selling point, especially to auto novice, who has no clue what ICE is.
(-) Transmission – CVT, worse than automatic. No manual gearbox option.
(-) Handling is , hmmm what can I say – a challenge. It was the runner up for the worst handling experience by BBC’s Top Gear (beaten by SMART fortwo). This is principally due to the low power and horrible traction on the wheels.
(-) Costs a lot of money! About 10,000$ more than a good Toyota Camry. For this price, you can buy a much better VW Golf or Jetta or the new GTI; a mini Cooper which has high mpg as well; or some of the several Hondas which reflect Toyotas achievements.
(-) It takes 5 years for you to profit from the mileage. So basically, you are not saving a lot on gas either.

Save the planet ?

Nope – not this one. It averages about 48 mpg. An old VW Golf Diesel averages at 65 mpg. Infact, the Audi/VW Diesel engine lies in the band of 55-75 mpg. Ofcouse, it matters how you drive the car. With Prius, it is hard to cross 70 mph, and with the Audi’s – you can cross 90 and lose some “efficient-performace”.
So if its not fuel that makes this car such a fashion statement – then what is it ?

(+) In many US states (including glamorous CA,FL,NY), Prius owners are allowed to drive on car pool lanes, not have to pay in selected parking lots, avoid a few taxes etc. (hmm)
(+) Less noisy – so gives the picture of a calm, tranquil mode of transport. Celebrities have it – many of them – so now it carries a Hollywood Drive of Fame.
(+) Easy political statement – can it get any easier than that? Buy a Prius and now you are captain planet Di’Caprio (who owns 3 Prius’ but drives around in an Escalade 4x4)
(+) Family 4 door, 5 seater – another added selling point. Ofcouse, if 5 people travel in it, the electric engine will never kick in – and you will be driving an 22,000$ Yaris (a 12,000$ non-hybrid car with the similar gasoline engine).
(+) The odd shape (based on a fish) is actually very aerodynamics at low speeds (abt 60mph). It has a drag coefficient of 0.24, which is very good and actually helps the mileage significantly.

In Conclusion

If you own a Prius (or considering to get one),

(*)then you probably own atleast 2 other vehicles for back up (good).
(*)you are a celebrity that needs attention cause you suck at what you do
(*)you are very rich, live in the city, need to buy milk from the next street
(*)you are the only occupant of the car, you don’t mind the low power, and have no where to go.

Don’t buy a Prius if

(*)you go on long distance travel (more than 20 miles/day) . Its good on the gas, but not on your back.
(*)you enjoy driving and the feel of mechanical power
(*)you are not the only passenger – and you plan on carrying SOME luggage at least.

Cars like the Mini Cooper, VW Golf and Honda Accord are more powerful, cheaper, have a high gas mileage and are truly wonderful driving experience. Infact, several Toyota cars including the new Yaris are very good alternatives for this science project they call – the Prius. The idea of Hybrid cars are good, but NOT THAT 1.