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> The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fue

by anamax 15y ago

> The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fuel efficient than typical combustion engines. I'm skeptical. Thermodynamic limits apply. While piston engines aren't near the limits, I'm pretty sure that they're around 50% of the limit and would be very surprised if this engine is over 80% of carnot. So, the only way this engine can be 2x as efficient is if it runs at a significantly higher temperature (which moves the limit). And, the only way that it can run without a transmission is if it has a very wide operating range. That's hard to do with combustion. And, unless the engine is both reversible and has torque at zero RPM, they'll need both a clutch and a reverse gear. If they use it to run a generator, they need to account for the electric motor, said generator, and maybe batteries. See diesel-electric locomotives. The prius combines the electric motor and the generator, but needs a transmission.

ent 15y ago
50% sounded like a lot to me so I checked wikipedia, according to which, most internal combustion engines have an average efficiency of 18-20%. So I guess it could be true if the Wave Disk Generator lives up to those promises. http://en.wikipedia.org/wiki/Internal_combustion_engine#Energy_efficiency http://en.wikipedia.org/wiki/Internal_combustion_engine#Ener...
- anamax 15y ago
  > 50% sounded like a lot to me so I checked wikipedia, according to which, most internal combustion engines have an average efficiency of 18-20%. From the wikipedia article that you cited: "Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%." I wrote that IC engines are running about 50% of the thermodynamic limits because 18/37 is around 50%. 18x2 is about 37, so there's no way for wave engines to be more than 2x as efficient as current engines unless they run at much higher temperatures. Since the relevant temperature is determined by the fuel.... Getting close to the thermodynamic limit is really hard. You didn't read the wiki article very carefully The 18-20% is of the total energy in the fuel. Heat engines, which includes both wave and piston engines, are subject to thermodynamic limits. The thermodynamic limits tell us the maximum efficiency, which is about 40% for the temperature at which ther

by anamax 15y ago

ent 15y ago

50% sounded like a lot to me so I checked wikipedia, according to which, most internal combustion engines have an average efficiency of 18-20%. So I guess it could be true if the Wave Disk Generator lives up to those promises. http://en.wikipedia.org/wiki/Internal_combustion_engine#Energy_efficiency http://en.wikipedia.org/wiki/Internal_combustion_engine#Ener...

anamax 15y ago
> 50% sounded like a lot to me so I checked wikipedia, according to which, most internal combustion engines have an average efficiency of 18-20%. From the wikipedia article that you cited: "Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%." I wrote that IC engines are running about 50% of the thermodynamic limits because 18/37 is around 50%. 18x2 is about 37, so there's no way for wave engines to be more than 2x as efficient as current engines unless they run at much higher temperatures. Since the relevant temperature is determined by the fuel.... Getting close to the thermodynamic limit is really hard. You didn't read the wiki article very carefully The 18-20% is of the total energy in the fuel. Heat engines, which includes both wave and piston engines, are subject to thermodynamic limits. The thermodynamic limits tell us the maximum efficiency, which is about 40% for the temperature at which ther