Development trends and prospects of biomimetic structure design for precooled heat exchange cores of aspirated precooled engines

Abstract

The air precoolers of existing pre-cooled combined cycle engines for hypersonic aircraft are generally composed of multiple sets of micro tube bundles, and there are problems such as high flow induced vibration and high processing requirements during the working process. Therefore, it is necessary to redesign the heat exchange core of the precooler and conduct further flow heat transfer research on it. The modification demand of precooler heat exchange core based on biomimetic fractals is analyzed, and its applications of honeycomb-like fractals, treelike fractals, and mixed structures on biological surfaces are sorted out, so as to the biomimetic concave-convex surface structures and hydrophobic structures applied to reduce surface flow resistance and suppress frosting. Three design examples of“cylindrical”biomimetic precooling heat exchange cores are given, which can be applied to the aerospace field. The development prospects of combining biomimetic microchannel heat exchange structures with precooler heat exchange core design are looked forward.

Keywords

• precooler
• heat exchange structure
• biomimetic fractal
• enhanced heat transfer
• flow resistance reduction