From a Convair manual.
The augmenter system of engine cooling was used on the CV-240 throughCV-440 aircraft - they are the two large "exhaust pipes" that come out of the rear of the nacelle.
"Exhaust System:
The exhaust system of each engine includes an exhaust manifold assembly and two augmentor assemblies. Each manifold assembly consists of eight siamese stacks and two single stacks that collect the exhaust gases and direct them into the bell mouth of two heat-exchanger type augmentor ducts (a muff surrounding each augmentor catches engine-cooling air which is heated in the muff for use with the anti-icing and cabin heat system). Two augmentor ducts in each nacelle extend aft from the fire wall to the nacelle afterbody where the exhaust gases are ejected into the atmosphere. The cross-sectional area of each augmentor duct is considerably greater than the combined area of the siamese and single stacks which lead into it and, since the exhaust gases from the engine enter the augmentors at a speed of approximately 1475 knots, a low pressure condition is created, causing cooling air to be drawn across the engine. Thus jet exhaust thrust augmentation is utilized to effect low-drag cooling, as conventional cowl flaps are not required and the airplane is therefore, subject to less drag. It is estimated that use of the augmentor type exhaust system, in addition to its value as a heat exchanger, adds 7-11 knots to airspeed.
High surface winds should not be allowed to blow into the tail end of the augmentor tubes while on the ground"
I think
Defenestrator may be too young to have seen a 310 with tubes.
See
https://en.wikipedia.org/wiki/Cessna...al_Airport.jpg