A pseudo three-dimensional topology optimization aerodynamic resistance reduction method for industrial flow components

The aerodynamic performance of industrial flow components is crucial in fluid transport systems in buildings, such as Heating, Ventilation and Air Conditioning (HVAC) systems, as excessive flow resistance can lead to increased pressure loss. Most of the existing low-resistance design topology optimization (TO) methods for building fluid distribution systems are based on two-dimensional models, ignoring the resistance in the thickness direction, which limits the optimization accuracy. We propose a pseudo-3D TO method. The nonlinear turbulent friction source term is incorporated into the Navier–Stokes equations to account for friction from the top and bottom walls of the corresponding three-dimensional flow channel, thereby capturing out-of-plane wall-friction effects in the two-dimensional model. The pressure loss coefficient and energy dissipation are set as multi-objectives, comprehensively characterizing resistance through boundary pressure drop and internal viscous dissipation. Z-bend verification shows that the pseudo-3D objective value is 5% lower than the traditional model value and deviates by only 4.5% from the full 3D result. The optimal Z-bend maintained a resistance reduction of 78-81% at different Reynolds numbers and aspect ratios. This pseudo 3D TO method overcomes the limitations of 2D models and provides an approach for low resistance design of industrial flow components. Yan Tian and colleagues propose a pseudo-three-dimensional topology optimization framework for resistance reduction in Z-bend channels. The results show that considering the assumed channel thickness improves the transferability of two-dimensional optimized designs to three-dimensional flow structures.