BACKGROUND

Contemporary engines used in aircraft produce substantial amounts of heat that must be transferred away from the engine in one way or another. Heat exchangers provide a way to transfer heat away from such engines.

Oil can be used to dissipate heat from engine components, such as engine bearings, electrical generators, and the like. Heat is typically transferred from the oil with heat exchangers to maintain oil temperatures at a desired range from approximately 100° F. to 300° F. In many instances, an external environment can be as low as −65° F. or the temperature of the aircraft fuel can be significantly lower than the oil temperatures. In such an example, a flow of cool air can be used to cool the oil at the heat exchanger with force convection. For example, high temperature (>700° F.) and high pressure bleed air can be cooled with ambient bypass air. Other applications utilize air, fuel, and oil to both cool and heat one another, depending on the need.

Additionally, heat exchangers can be placed in the aircraft for dissipating heat generated by electrical systems, such as within an avionics chassis. The heat exchangers can include a plurality of elements, such as conduits, to draw heat from the electrical components. The heat exchanger can be used to dissipate the heat drawn from the electrical components.

BRIEF DESCRIPTION

In one aspect, the present disclosure relates to a method of forming a heat exchanger including: forming a monolithic core having a first set of flow passages; and additively manufacturing onto the monolithic core a first manifold, where the first manifold defines a first fluid inlet that is in fluid communication with the first set of flow passages and at least a portion of the first manifold has a coefficient of thermal expansion less than a coefficient of thermal expansion of the monolithic core.

In another aspect, the present disclosure relates to a method of forming a heat exchanger including: forming a monolithic core having a first set of flow passages from a first material having a first coefficient of thermal expansion; and additively manufacturing a first manifold from a second material different than the first material onto the monolithic core in fluid communication with the first set of low passages having a second coefficient of thermal expansion lower than the first coefficient of thermal expansion.

In yet another aspect, the present disclosure relates to a heat exchanger including monolithic core body having a first set of flow passages and a first coefficient of thermal expansion. A first manifold is unitarily formed with the monolithic core body in fluid communication with and defining a first fluid inlet for the first set of flow passages, and having a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion.

