When the turboprop engine is active, the propeller shaft rotates and causes the propeller to rotate as well, which in turn generates thrust. The propeller shaft rotates because of the torque (or twisting moment) created by the turbines of the engine and then which is conveyed to the propeller shaft. My question is that if I am trying to conduct a FEA analysis for the mount at which this engine is attached, should I also apply this torque on it or not? I was thinking that I shouldn't apply any kind of torque at this engine mount since I don't think that engine itself is rotating at all because of any twisting moment, but it is recommended that the torque should always be taken into account while conducting such analysis. Moreover, I believe that there exists some bearings somewhere inside the engine which makes the engine mount to not take any kind of torque generated by the engine.
For every action there is an equal, but opposite, reaction.
Never found a case that this is not true.
Torque reaction on the P51 even caused uneven tire wear: https://www.aopa.org/news-and-media/all-news/2007/august/pilot/north-american-aviation-p-51d-mustang
So, if you open the bonnet or hood of a car and run the engine with it in neutral, then blip the throttle you will see the engine try to rotate in the opposite direction to that which it runs. Yet another example and it’s not connected to the output…
Yes, indeed it creates a reaction torque equal and in opposite direction in the frame of the airplane. All the engine mounts have diagonal braces designed to transfer the propeller's torque to the wing or mount.
It is immediately noticeable in a helicoper with a disabled rudder propeller and will cause imminent danger of crash because it causes the copter to spin.
I am a private pilot and especially in single-engine airplanes like Cessna 182 the torque of the propeller causes significant loss of authority on the yoke and has to be dealt with. We need to control the roll and yaw (rotation of the plane on the horizontal plane about the Z-axis) it causes with the ailerons combined with the rudder. Thi procedure is different for each airplane and the pilot must follow the manufacturer's instructions. Here is a link to torque reaction.
after some comments I googled specifically jet engines' torque. and summing up the statement the answer is yes they do create torque.
unless in exceptional cases like in vertical lifiting Harrier fighter jet were there is no stream of air at take off to counter the torqu they have added a fan on the front, turning the opposite direction of the jet engine with revrse torque to cancel the engine torque.
The engine mount (connection) is responsible for the maximum horizontal force on the plane including the effect of the thrust, and its weight.
The pictures below show how the engine is attached (mounted) to the pylon, which is attached to the wing. The simple connections (19a & 19b) make me hesitate to think they can resist the torque (rotated about the axis of travel). Or maybe the torque is rather small.