So, I’ve been thinking a lot about radiators lately. When you’re driving in a very low car, sometimes all you see of the vehicle behind you is the big chrome grille designed to let air through to reach the radiator. Even cars with excellent aerodynamics are forced to have this component that, by its very nature, requires wind resistance to operate. There is even a fan to expend more energy to make sure that air is passing over the radiator at all times. If there was a way to get rid of the radiator, fuel efficiency in vehicles would be increased. Maybe not a lot, but a measurable amount that would certainly add up.
The only catch is that the radiator is really important. Owners of old air-cooled Volkswagens can testify to that; those engines had no radiators and were not terribly reliable — plus, they paid the same aerodynamic price to have the air pass through the engine compartment.
Internal combustion engines produce a lot of heat; in fact, thermodynamics says that the hotter they burn, the more efficient they are. My clever nephew Gerald, when presented with the Radiator Conundrum, realized immediately that one solution is simply to embrace the heat rather than get rid of it. If one builds the engine out of materials that can withstand much higher heat than modern engines, then you can let that sucker get really, really hot and actually burn more efficiently at the same time. It’s win-win! I know that there are experimental ceramic engines built around this principle, and it’s about time to get them into production vehicles.
Superhot engines may be good, but superhot engine compartments are not. There’s still going to be some waste heat to manage, if only for safety. My thoughts turned to ways to take at least some of the waste heat and make use of it. By converting the heat energy into some other form of energy, say, electricity, we can simultaneously cool the engine and reclaim some of the waste. Perhaps we could even do away with the alternator, which costs a typical car a couple of horsepower. By reducing the load on the engine once again we can increase efficiency.
Unfortunately, that’s easier said than done (or it would be done already). However, with a really hot ceramic engine, I think it would be possible to use the thermoelectric effect. All you need to do is embed series of different metals along the heat gradient within the engine to create thermopiles. (More modern thermopiles are used to power deep-space probes.) Thermopiles can supply large amounts of current, but only at low voltages. With enough of them, however, you would have a cooling system that simultaneously recharged the car’s battery. If the system worked really well, you could even use surplus current to power a small electric helper motor.
So, anyone up for investing in Jer’s Radiatorless Engine? If it works, we’d make a fortune!