COMPLEX HEAT EXCHANGERS – THE COMBINATION OF FRACTAL GEOMETRY AND ADDITIVE MANUFACTURING

Complex structures for heat exchangers in high-temperature applications are developed in the research project instaf. The driving force behind these developments is the new design freedom given by the additive manufacturing (AM) of ceramics. With this technology, the complexity of form is no longer an obstacle for profitable solutions. The application of fractals in this context is very promising, since it takes advantage of the new freedom while on the other hand the algorithms for the generation of such forms are relatively easy to handle. This paper presents some proposals for heat exchangers or mixing structures, which are inspired by natural formations. The underlying assumption is: the efficiency of a heat exchanger increases with the surface area of the wall between the fluids. The surfaces here are derived from a series of fractal curves within a given outer shape. The algorithms for the curves use the Lindemayer system (Lsystem), which allows for steering a large variety of curves systematically