MRC_Hans
Penultimate Amazing
- Joined
- Aug 28, 2002
- Messages
- 24,961
The last thing first.. Germans (and allied) wanted jets mainly because they were fast and powerful. Easy to build they were not. Strictly speaking, a turbine engine is simpler than a piston engine of simiar output, but the technology involved, because of the high revolutions and temperatures, is difficult. -And was not mastered fully by Germany during WW2; their jet engines had a life expectancy of about 50 hours!
Now, turbines. The main reason for using turbine engines almost exclusively for aircraft (even propeller aircraft), is the excellent weight to power ratio. This affects ecomomy also, because in an aircraft, you obviously have to lug the engines into to air too, so a lighter engine means more payload, thus better economy, even if the turbine is basically not quite as economic as a piston engine. Another advantage of the turbine is that it uses a less sophisticated fuel. Jet fuel is either JP1, which is much like diesel fuel, or the military JP4, which is more like kerosene.
Steam turbines for ships and power plants can be made quite effective, I have not looked this up recently, but I believe they are as good as piston steam engines, and much simpler.
Turbine negined have been tried for cars, both for racing and in the street, but there are a number of problems:
- Delayed throttle reaction.
- Low efficiency (the light weight only partly compensates this on a surface vehicle)
- Complex maintenance.
- Narrow useful RPM range.
It seems that the versatile and rugged old piston engine is going to stay with us for quite some time to come.
Hans
Now, turbines. The main reason for using turbine engines almost exclusively for aircraft (even propeller aircraft), is the excellent weight to power ratio. This affects ecomomy also, because in an aircraft, you obviously have to lug the engines into to air too, so a lighter engine means more payload, thus better economy, even if the turbine is basically not quite as economic as a piston engine. Another advantage of the turbine is that it uses a less sophisticated fuel. Jet fuel is either JP1, which is much like diesel fuel, or the military JP4, which is more like kerosene.
Steam turbines for ships and power plants can be made quite effective, I have not looked this up recently, but I believe they are as good as piston steam engines, and much simpler.
Turbine negined have been tried for cars, both for racing and in the street, but there are a number of problems:
- Delayed throttle reaction.
- Low efficiency (the light weight only partly compensates this on a surface vehicle)
- Complex maintenance.
- Narrow useful RPM range.
It seems that the versatile and rugged old piston engine is going to stay with us for quite some time to come.
Hans