It's a bit tangent but are there any differences between F110-GE-129 engines that powers aircrafts in twin-engine configuration and single engine configuration? Any difference in dimensions, ECUs, software etc.? In essence, can the engine power an F16 if it was dismounted from an F15 and vice versa?
There are differences but not dimensional w.r.t physical interface and attachment points etc.
One engine can 100% substitute another, but in practice this is rarely done as there are optimisations done on the production + qualification side (w.r.t the inlet, FADEC tuning, trim etc) given their different airflow requirements and dynamic thrust responses etc.
i.e push come to shove yes you could switch between GE and PW on almost any F-16 AFAIK, but there will be trade-offs and performance losses involved. Not ideal, but its an idea being explored for example retiring engines early and providing these to both platforms:
Changing the export rules to make the engines available to like-minded countries with F-15 and F-16 fighter jets benefits Japan in ways well beyond the money.
japan-forward.com
Originally the main reason to bring GE into the F-15 powerplant (and thus F-16 downstream too given these were bound together by the original economy of scale argument) was for the pentagon to be able to apply pressure on PW to quickly find solutions for the original engine issues.
@Nutuk ,
I think you will find that with twin engined jet propulsion, both engines rotate in the same direction. If memory serves it is generally anti clockwise looking at the engine from the front. Yet almost all RR engines and CFM engines rotate clockwise. Almost all GE and P&W engines rotate anti clockwise. This is valid, be it single or multiple engines.
What makes a difference is the FADEC system they use. A single engined plane’s FADEC is very different to a twin engined plane’s FADEC. (Full Authority Digital Engine Control)
Also F16 has fixed inlets and F15 has variable inlets.
F15 Eagle air intakes are movable and change their angle during flight to give the optimal air flow for the engines under current conditions of airspeed, altitude, and throttle setting
GE produces F110-129 engines in A,C and E versions for F15 twin engine
GE produces F110-129 engines in B and D versions for F16 single engine
These engines are produced to perform to spec in the platform they were meant to fly.
The latest spec F15 engine is F110GE129-E version that flies F15EX. This is the engine we have on KAAN.
Again we should ask this question to
@Nilgiri for further insight in to difference.
Yes you are more or less correct.
The "doubling" gyroscopic, torque, jetwash effects et al. are minimal given the size of the aircraft involved relative to the powerplant dimensions, weight and moment distributions involved.
When the % is intense enough (say a small enough aircraft with say large enough propellers with sizeable rotatable moments of inertias etc relative to the overall weight/positioning/dampening of the system)....then you build the argument for counter-rotation.
That's why its a fairly common feature on propeller aircraft as propellers notably have far larger relative diameters to the aircraft.
i.e the issue is important for say a V-22 to take the extreme, that the props rotate counter to each other (even for level cruise flight, as its even more clear for VTOL/hover as a tail rotor is done away with). Its same issue in lot of propeller aircraft, having 2 gearboxes (one for each direction) is a cost, but is worth it to address the issue at this %intensity and helping counter as much of the "combined" propwash effects at various flight conditions as possible too (that are not as prevalent in jetwash given the jet velocity and downstream distance away from a/c etc the issue starts to crop up which tends to be irrelevant)
Otherwise its not economical to make two sets of production and MRO support lines for clockwise and counterclockwise rotation for one engine. i.e just pick one. That covers almost any jet aircraft, single or double engine.
There is the issue of spin for double and multi engined jet aircraft (especially commercial where they can be spread quite far from the center of mass).....with regards to the (combined) gyro effect being able to add to it and hampering spin recovery compared to having it neutral (by counter rotating engines) and not hampering this. But these cases are very rare to consider and are more economical to address in the larger control system to begin with. The issue materialises more significantly with propeller aircraft and hence often is addressed by counter rotation becoming more relevant again relative to production+MRO costs.
There are however a few exceptions where the intensity issue becomes severe enough for jet aircraft like the Harrier given its relative small size, large engine involved, large diameter fan involved etc and its peculiar requirements imposed at low speed (the vertical portion and pilot weight distribution etc) that made it easy to upset if the engine was adding its torque and gyroscopic effect (especially in the pitch - yaw coefficient in the stability control matrix). Hence the Pegasus engine had to be specially designed to have the LP spool rotate in opposite direction to the HP spool to get the net torque and gyro effect as low as possible.
But these exceptions are rare...generally the effects are minimal to the larger control-stability, aeroelasticity and aerodynamic matrices (specifically their eigenvectors) involved in jet aircraft...so the economics of having just one cookie cutter design w.r.t rotation overrides it easily.
Apologies for any typos/errors, its off top of my head and I proof read just once.
Edit: changed contra to counter (these are two different things).
