Saturday, April 18, 2009

"Multi-core" car engine

The Green Multi-core

I was talking to my roommate who is a Mechanical Engg major. I learned that the car's combustion engine, say of 1600cc combustion capacity, does not have all this volume in one chamber. It has multiple "cylinders", each with two valves, which share this capacity equally. So if the engine is label V8, it has 4 cylinders, each of 400cc volume. Each of these cylinders also has a dedicated spark plug which ignites it's fuel injection, and is, in turn, connected to the crankshaft through a piston.

I know that sometimes the car seems less powerful (and may drive slightly bumpy) because a cylinder went down (the spark plug, usually). If the car can still operate almost fine with a cylinder down, why cannot the engine be designed to operate in dual (or multiple) modes where different number of cylinders are active in the two modes, say half and all. The all-mode can be the regular, full power mode while the half-mode can be the less powerful but more fuel-efficient mode, analogous to a multi-core processor chip.

I have not tried to do a technology/literature survey. Such a design may already be underway. I would be happy to learn about it.


The Green Hybrid

Some time back, while in India, I had the idea of a car that could operate in both the fuel-mode and the electric-mode, so that at traffic crossings and jams, it would operate in the pollution-free electric-mode and in sparser outskirts with higher speeds, would automatically switch to the regular fuel-mode. While I was discussing this with a Mechanical Engg friend, I came to the US, only to see hybrid cars already on the streets. Rest is just implementing a speed-mode transition policy, which will eventually happen as the need becomes more prominent here. (The need is surely more prominent in India, where pollution is more severe. A low-cost implementation would thrive as a business in one of the biggest markets of the world.)


The Green Recycler


It's interesting how I have "Green" in all three parts of this post. For two of these, that was not a part of the original idea at all. I was just trying to design something more efficient and economical. It's rewarding to see Green and Economical rhyme. Or maybe not. One could as well ask why Green is the most important of our economic problems today. It's a punishment to one and all. But I would like to stick with the reward-view, since that's future and hope.

The Green Recycler goes like this. Every time we take pickup from the engine, we burn fuel, generate energy and pump it into the car. Some of it is lost as heat, but a major portion is used to accelerate the vehicle. Why then, when we brake, do we not recover that energy, only to reuse to pickup again? All we need is to apply brakes electromagnetically instead of mechanically, using magnetic force to brake instead of friction. The reverse current thus generated can be stored and reused. The answer again came from my roommate, who told me that the MagLev train in Japan does exactly this. Perhaps it's not yet economical enough to do this for vehicles. But yeah, the idea is already there, and will make it's way as we develop. It seems we (our generation, that is) are now educated enough so that our ideas are at par with or leading the state of the art/development. We are ready to contribute.

1 comment:

Unknown said...

I just realized that the Hybrid cars today (Toyota Prius and Honda Civic Hybrid being two such) do exactly the "green recycling" thingie to give that high mpg. Good.