Turbine Disc Retaining Nut Cooling Passage Design

The patent employs curved and rounded passage geometries rather than sharp corners or abrupt transitions. The cooling passages feature smooth bends and gradual diameter changes, which eliminate stress concentration points that would otherwise occur at sharp edges or sudden geometric transitions. This curved geometry maintains effective cooling flow paths while significantly reducing localized stress concentrations in the disc material.

The patent optimizes the parameters of the cooling passages, including their diameter, length, spacing, and curvature radius, to achieve a balance between cooling efficiency and stress distribution. By carefully selecting these parameters, the design ensures adequate cooling coverage while maintaining structural integrity and minimizing stress concentrations in the surrounding disc material.

The patent divides the cooling system into multiple separate cooling passages distributed throughout the disc structure, rather than relying on a single large cooling channel. This segmentation allows for more uniform heat removal across the reduced disc volume, as each passage can independently cool its local region. The multiple smaller passages provide adequate total cooling surface area and heat transfer capacity even in a compact disc design.

The patent utilizes three-dimensional cooling passage routing that exploits the volumetric space within the disc rather than relying solely on two-dimensional surface cooling. By creating passages that extend radially, axially, and tangentially through the disc thickness and radius, the design achieves efficient heat removal from the entire volume of the reduced-size disc, ensuring adequate cooling performance despite the smaller overall dimensions.