Topology optimisation of conformal cooling channels in injection moulding: a scaling strategy for forced convection in high Reynolds number flows

Abstract Conformal cooling channels for injection moulds play a vital role in improving the efficiency and quality of the moulding processes by enabling more uniform heat removal. This study develops an integrated framework for optimising such cooling channels by topology optimisation, addressing key challenges in heat transfer under turbulent flow conditions. A scaling strategy is proposed to approximate high velocity turbulent heat transfer using a lower velocity laminar flow model. The scaling strategy overcomes the limitations of traditional Darcy potential flow models by incorporating inertial effects, which are critical for designing complex cooling layouts. Verification against high-fidelity Reynolds-Averaged Navier–Stokes simulations confirms the effectiveness of the scaling model in delivering reliable and physically accurate optimisation results. The optimisation process explores multiple performance and manufacturability constraints. Pressure drop constraints reveal the trade-offs between cooling efficiency and fluid resistance. Temperature uniformity constraints significantly reduce surface temperature deviations, particularly in critical regions such as corners and protrusions. Length scale constraints ensure manufacturability by regulating feature sizes, balancing structural simplicity with thermal performance. By combining these innovations, the proposed methodology establishes a robust foundation for designing advanced conformal cooling channels, offering practical solutions for thermal management in industrial applications.