Thermal-fluid-structural response and POD-RBF stress-field reconstruction of a high-temperature high-pressure control valve

High-temperature, high-pressure control valves in steam systems experience coupled flow acceleration, heat transfer, pressure loading, and constrained deformation, making repeated structural assessment expensive. A one-way thermal-fluid-structural procedure is established for a normally open control valve, and a POD-RBF reduced-order model is developed to reconstruct the stress field along a measured heat-up and pressurization path. Wall pressure and temperature from the CFD model are transferred to the solid domain, and stress snapshots from six training conditions are aligned on a common reference mesh before modal reduction and radial-basis interpolation. The representative 17.2 MPa/575 °C condition gives a maximum velocity of 15.926 m/second, maximum equivalent stress of 244.96 MPa, and maximum deformation of 0.61765 mm. For the unseen G7 condition, the maximum-stress error is 0.80%. Extreme-condition stress classification identifies the passage transition as the location with the lowest safety margin, although the calculated stresses remain within the allowable limits.