stinsonbr said:Without any of the math, my guess is it would be very inefficient. Jets consume a lot of fuel. While their thrust can be impressive, when you scale them down to the size of a loaf of bread they become rather ineffective at producing thrust compared to a propeller.
Energy loss might also be an issue. Using the thrust from jets to spin a wheel in order to turn something might mean your output is significantly lower than your input, since the little jets are gas guzzlers.
As an example, I ran a small jet engine in a lab, about half the size of a football (American). We used kerosene as fuel, and it produced about 4 to 5 lbs as max thrust. When we took the same jet and slapped a propeller on the front of it, it produce about 20 lbs. It also went through a gallon of fuel (3.8L) in just over 20 minutes of run time (I'm sure however there are much better designs, by no means was it a state of the art engine).
The efficiency of a jet-powered rotor engine is typically between 70-80%. This means that 70-80% of the energy produced by the engine is converted into useful work, while the remaining percentage is lost as heat or through other inefficiencies.
The efficiency of a jet-powered rotor engine is typically measured by taking the ratio of the engine's output power to its input power. This can be calculated by dividing the thrust produced by the engine by the fuel flow rate.
The efficiency of a jet-powered rotor engine can be affected by a variety of factors, including the design and size of the engine, the type and quality of fuel used, and the operating conditions such as altitude and air temperature.
Yes, the efficiency of a jet-powered rotor engine can be improved through ongoing research and advancements in technology. For example, improvements in engine design, materials, and fuel efficiency can lead to higher overall efficiency.
Compared to other types of engines, such as piston engines or turboprop engines, the efficiency of a jet-powered rotor engine is generally higher. This is due to the continuous flow of air and fuel through the engine, allowing for more efficient energy conversion. However, the efficiency of a jet-powered rotor engine may be lower than other types of jet engines, such as turbofan engines, which have additional features for increased efficiency.