Abstract: A method includes additively manufacturing a heat exchanger with a plurality of fluid passages extending in a flow direction through the heat exchanger. The method includes chemical milling interior surfaces of the plurality of fluid passages, wherein chemically milling includes flowing chemical milling fluid through an inlet of and inlet header to an outlet of the inlet header and into the plurality of fluid passages from the outlet of the inlet header. The inlet header includes a diffuser structure in fluid communication between the inlet and the outlet, configured to promote even distribution and flow of the chemical milling fluid from the outlet of the inlet header into the plurality of fluid passages.

Abstract: In accordance with at least one aspect of this disclosure, a system includes a liquid-gas separator. The liquid-gas separator includes: a substantially planar body configured to be seated in a fluid flow to separate a flow of liquid from the fluid flow, one or more apertures disposed in the body configured collect the flow of liquid, and one or more diverters integrally formed on or in the body configured divert the flow of liquid towards the one or more apertures. In certain embodiments, the planar body can be additively manufactured.

Abstract: A method includes additively manufacturing a heat exchanger with a plurality of fluid passages extending in a flow direction through the heat exchanger. The method includes chemical milling interior surfaces of the plurality of fluid passages, wherein chemically milling includes flowing chemical milling fluid through an inlet of and inlet header to an outlet of the inlet header and into the plurality of fluid passages from the outlet of the inlet header. The inlet header includes a diffuser structure in fluid communication between the inlet and the outlet, configured to promote even distribution and flow of the chemical milling fluid from the outlet of the inlet header into the plurality of fluid passages.

Abstract: In accordance with at least one aspect of this disclosure, a system includes a liquid-gas separator. The liquid-gas separator comprises, a substantially planar body configured to be seated in a fluid flow to separate a flow of liquid from the fluid flow, one or more apertures disposed in the body configured collect the flow of liquid, and one or more diverters integrally formed on or in the body configured divert the flow of liquid towards the one or more apertures. In certain embodiments, the planar body can be additively manufactured.