BIM-based immersive virtual reality framework for understanding hydraulic transients in pressurized pipelines

This paper presents a BIM-based virtual reality (VR) framework for the immersive visualization of hydraulic transients in pressurized hydropower systems. The approach integrates three-dimensional geometries derived from BIM models with hydraulic simulations based on the Method of Characteristics. The hydraulic model is implemented in an external computational environment and accounts for key boundary conditions, including upstream reservoir levels, surge tank oscillations, and turbine-related orifice flow at the downstream boundary. Simulation outputs are exported as time-dependent datasets and mapped onto discretized pipeline segments within a game engine platform. Dynamic visualization is achieved through real-time modification of textures and color encoding driven by custom scripts, enabling the representation of pressure wave propagation and flow variations. The framework is applied to a real hydropower plant case study, where users can simulate valve closure maneuvers within an immersive VR environment accessed through head-mounted displays. Results derived from a user study involving 29 participants with diverse backgrounds suggest a high level of perceived usefulness, highlighting how the integration of BIM models, numerical simulations, and immersive VR can support the understanding and visualization of complex hydraulic phenomena in engineering contexts.