After taking into account the different types of engine cowlings & exhaust pipes, and the different pylon designs and mounting configurations ......... my guess would be that the affect of disturbance on both the hot core gases and the by-pass airflow (as mentioned in your topic's title), would be between none and .000005%.
I'm going to try to read your mind a bit!
If you were to look at the first 2 photos of the B747 & B767 below, you might be wondering about whether or not the pylon affects the bypass airflow because the by-pass air exits the engine beside the pylon .... several feet ahead of the pylon's trailing edge. In this case, the pylon may actually help the by-pass airflow (not disturb it), by straightening it out a bit ... just a guess. (engine types anyone? - RB211, PW4000, CFM, GE
The situation in the case above wouldn't be an issue on airliners with engines that have one full length cowling with both the by-pass air and hot core gases exiting from the same single jet pipe ....... like the engines on the B757 & A320 in these 2 photos. (engine types anyone? - RB211, PW4000, CFM, GE
I don't believe the engine/pylon designs of some older clasics with their low by-pass engines would cause any airflow disturbance problems ...... such as on the DC-8 & 737-2.
I think airliners with aft/side mounted engines are exempt from this issue too ..... such as the ERJ-145.
View Large View Medium
Photo © Justin Wood
>> You asked ......... "Are there any sections inside the engine (besides the mounting points) designed considering the disturbance the pylon creates on the airflow?"
I don't know, but I don't think so. On a side note, the jet engines on MD
-80s have guide vanes inside the intake infront of the fan which I believe are for re-directing the intake air to make the fan more efficient ..... but that's got nothing to do with your questions. Sorry!
View Large View Medium
Photo © Bruce Leibowitz
Finally, if by saying ..."the disturbance the pylon creates on the airflow"
, you are talking about any "turbulence" that is created by the pylons, on any airliner regardless of the engine/pylon mounting design, then I would have to say ...... I doubt it!
By the time any turbulence caused by the pylon reached the by-pass & hot core airflow behind the engine, the airflow's work (thrust!) would have already been done ...... thus there would be no disturbance affect.
Just my thoughts.