US Patent 10041741 Heat exchanger for gas turbine engines

A heat exchanger defines an annulus divided by a plurality of radial plates extending longitudinal along the annulus, into a plurality of channels. A first group of the channels form an oil passage and a second group of channels form a fuel passage. The channels in the respective first and second groups are circumferentially alternately positioned one to another, and heat transfer from the oil passage to the fuel passage takes place through the radial plates.