Chiung-Lin Chu

Cooling-water intake basins in coastal power plants may experience particle retention and sediment deposition when complex inlet geometry produces large-scale recirculation and low-velocity zones near intake structures. This study examines the use of submerged barriers to mitigate particle retention in a de-identified coastal power-plant intake basin using hydraulic model experiments and hydraulic-model-supported three-dimensional computational fluid dynamics (CFD). A geometrically consistent model-scale configuration, including the inlet channel, main basin, three intake openings, and two outlet passages, was used to preserve site confidentiality while retaining the essential hydraulic mechanisms. Surface-flow patterns, water-depth variations, and sediment-deposition behavior were measured in the physical model and used to assess the numerical model. The numerical results, supported by the available hydraulic-model observations, reproduced the dominant counterclockwise recirculation and a broadly similar retention-prone region. The simulated water depths agreed closely with the measurements, with relative errors below 0.50% for the finest mesh. A water-depth-based grid-sensitivity assessment using 1,221,165; 2,414,216; and 3,378,840 computational cells further showed that the predicted mean water depths remained within 1.15% of the experimental measurements. The assessed numerical model was then applied to examine submerged-barrier configurations installed near the inlet-to-basin transition, with the barrier-performance interpretation limited to the tested mesh, the assumed representative particle condition, and the available qualitative flow/deposition evidence. Under this assumed particle-tracking condition, the original configuration retained 6989 particles at t = 200 s, whereas the 6 cm submerged barrier reduced the retained-particle count to 4956, corresponding to a reduction of approximately 29.1%. In contrast, the 15 cm emergent barrier increased the retained-particle count to 7573 because it blocked overtopping flow and induced new separated low-velocity regions. These results indicate that, among the tested configurations and under the assumed representative particle condition, the 6 cm submerged barrier yielded the lowest retained-particle count, whereas an excessively high barrier may deteriorate the internal flow structure and increase particle accumulation.

Forced convection in incompressible viscous flows is a fundamental heat transfer mechanism encountered in a wide range of engineering applications. In this study, a meshless numerical framework is proposed for the simulation of two-dimensional forced convection problems by coupling the generalized finite difference method (GFDM) with the projection method. The governing incompressible Navier–Stokes equations and the energy equation are discretized in space using the GFDM, which approximates spatial derivatives on scattered nodes through local Taylor series expansions and moving least squares techniques, thereby completely avoiding mesh generation and numerical integration. Temporal advancement is performed using a classical projection method to efficiently decouple the velocity and pressure fields while strictly enforcing the incompressibility constraint. The proposed GFDM–projection method is validated through several benchmark problems with different geometrical complexities. Detailed comparisons of velocity profiles, streamline patterns, temperature distributions, and local Nusselt number variations with previously published numerical and experimental results demonstrate excellent agreement. The results indicate that the proposed meshless method provides an accurate, stable, and computationally efficient alternative for simulating forced convection heat transfer in complex two-dimensional domains.