ThermohydraulikSimulationen

Thermohydraulics is the study of the interaction between heat transfer and fluid flow in a system. It analyzes how temperature fields drive and are driven by fluid motion, including convection, conduction, and radiation, across single-phase and multiphase flows. The core problems involve determining velocity, pressure, temperature, and phase distribution within engineered components such as pipes, reactors, heat exchangers, and cooling circuits. Governing equations include the conservation of mass, momentum (Navier-Stokes), and energy, often supplemented by species transport or phase-change models. Dimensionless parameters such as Reynolds, Prandtl, Grashof, Nusselt, and Weber numbers help characterize regimes and scale results.

Thermohydraulic analysis is essential in power generation and process industries. In nuclear reactors, it informs reactor safety by predicting coolant flow and boiling, critical heat flux, and emergency cooling. In HVAC, it guides air and liquid cooling systems. In chemical processing, it helps design heat exchangers and reactors to ensure efficient transfer and safe operation. Methods range from analytical solutions for simplified geometries to experimental measurements and numerical simulations. Computational fluid dynamics (CFD) enables detailed three-dimensional predictions, including turbulence modeling and, for two-phase flows, annular, slug, or dispersed regimes along with boiling and condensation phenomena.

Challenges include accurately modeling turbulence, multiphase interfaces, and phase-change heat transfer, as well as ensuring numerical stability and validation against experimental data. Ongoing research seeks to improve models for complex geometries, transient behavior, and coupled multi-physics interactions.