# Thrust by turbo fan jet engine

How much thrust can I produce with a turbofan jet engine without injection of fuel and with just compression of air, which will be heated by convection if initial temperature of air of 20 oC and its temperature after compression is 1400 oC, which is then diffused through nozzle of the jet.

I want to produce approximately 6.8 kN of thrust.

• You don't get anything out with the compressor. You have an electric or diesel motor turning a ducted fan and turning a compressor. If you don't need the compressed air, get rid of the compressor and just turn the fan. A jet engine burns fuel just like a diesel. No fuel, no power. Some of the heat of compression will always be lost to the environment and not recoverable, so it is always lossy without fuel burn. Feb 26 '20 at 11:39
• That wasn't my downvote, btw. Feb 26 '20 at 11:41
• What if i power compressor using a motor or some other source, and compress air and heat it using some source, then alow it to expend while keeping the cross section area content, and let ut flow out of nozzle, Feb 26 '20 at 11:44
• I want compressor to suck and compress air, then i want to expand air by heating it using some source but not fuel, its discharge will be same but volume will be increased, so velocity of air coming out of jet will be more, i think thrust is proportional to velocity of air coming out of jet, so there will be some thrust, Feb 26 '20 at 11:46
• I am compressing air for reducing cross section area of duct through which it is flowing and to increase its temperature, then i have some source of heat. In the next part or section of jet AKA combustion chamber., if temperature in the combustion chamber is 1400 degree C, and them i have a diffuser or nozzle to diffuse air out at greater velocity, volume will increase due to temperature, and its discharge must be constant so velocity must be high, now tell me how much thrust roughly it can produce. I just want 6.8 KN of thrust. If temperature raise if 1380 degree C, and what will be minimum c Feb 26 '20 at 11:53