An Additively Manufactured Two-Fluid Heat Exchanger Designed With Topology Optimization Tools

Abstract Heat exchangers are widely used in gas turbine plants for several purposes, with traditional designs including shell and tube or plate-fin coolers. Recent developments in additive manufacturing techniques such as laser powder bed fusion have led to interest in the use of alternative heat exchanger designs, such as those generated with topology optimization techniques. These design techniques can result in more efficient heat exchangers with complex internal structures which can only be manufactured using additive techniques. Nevertheless, manufacturing heat exchangers for gas turbine applications with additive techniques is not straightforward. Two of the primary difficulties in the use of laser powder bed fusion are the printing of materials with high thermal conductivity such as copper alloys as well as powder cleaning from any complex internal channels such as those which may be generated by topology optimization tools. To investigate the feasibility of combining topology optimization techniques with additive manufacturing to design novel heat exchangers a proprietary topology optimization software is used to design an oil/air cooler with significantly reduced size and pressure drop compared to an equivalent one based on a conventional design. In a potential future application on oil circuits, this could consequently result in an optimization of the lubricant oil circuit components, for example pumps, piping, console dimensions and weight. The design was also optimized to consider manufacturability constraints such as overhang angles and minimum thickness as well as to correct in line with feedback from initial trial prints. The cooler was manufactured using additive manufacturing techniques.