Computational Analysis of the Cooling Channel Performance of a Plasma Transferred Arc Nozzle Incorporating Gyroid Lattice Structures

The thermal loading experienced by Plasma Transferred Arc (PTA) welding nozzles places stringent demands on internal cooling performance, often limiting component life and process stability. Additive manufacturing enables the incorporation of triply periodic minimal surface (TPMS) lattice structures into internal channels, potentially improving heat extraction without compromising flow efficiency. This work presents a purely computational study of a PTA nozzle redesigned to integrate gyroid lattice structures within its cooling channel. Conjugate heat transfer (CHT) simulations were performed to compare the original machined channel with two lattice configurations (walled and offset), evaluated at different unit-cell sizes. The models simultaneously captured the coolant flow, external shielding-gas convection, and fixed temperature applied to the nozzle's frontal face. Results indicate that the inclusion of lattice structures significantly enhances heat transfer (the convective coefficient increases by ۷۸.۳ % compared to the baseline channel in the best configuration), reducing mean nozzle temperatures by widening the effective heat-exchange area and promoting internal flow mixing. Among the evaluated architectures, the offset gyroid with a ۳ mm unit cell size provided the best compromise between thermal performance and pressure drop. Conversely, larger cell sizes or walled configurations increased hydraulic losses to unfeasible levels without a commensurate thermal benefit. The findings demonstrate the potential of lattice-integrated cooling channels to improve PTA nozzle reliability and provide a computational framework for guiding future experimental validation and AM-based fabrication.

کلیدواژه ها:

Plasma transferred arc nozzle ، Cooling channel design ، Triply periodic minimal surface gyroid lattice ، Additive manufacturing ، Conjugate Heat Transfer ، Computational fluid dynamics