The discussion revolves around the efficiency of a jet-powered rotor engine, specifically comparing it to traditional engines like gas turbines and exploring the feasibility of using jets for propulsion in a rotating machine similar to an aeolipile, but powered by petrol combustion.
Participants do not reach a consensus on the efficiency of the proposed jet-powered rotor engine. There are competing views regarding its practicality and efficiency compared to existing technologies like gas turbines and propellers.
Some limitations include the lack of mathematical analysis and the dependence on specific design assumptions. The discussion also highlights the challenges in deriving thermodynamic equations for those not specialized in the field.
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).