Sökning: "RANS"
Visar resultat 1 - 5 av 120 avhandlingar innehållade ordet RANS.
1. Methodologies for RANS-LES interfaces in turbulence-resolving simulations
Sammanfattning : Hybrid Reynolds-Average Navier-Stokes (RANS)-Large-Eddy Simulations (LES) techniques are now seen by the aeronautical industry as the most promising turbulence-resolving approaches for complex high-Reynolds-number turbulent flows with regard to cost and accuracy. However, connecting RANS and LES simulated flows is a challenging task and needs special attention in order to increase simulation robustness and accuracy. LÄS MER
2. Development of a Free Surface Capability in a RANS Solver with Coupled Equations and Overset Grids
Sammanfattning : This thesis is a result of investigations carried out during the implementation of a free surface capturing method in a RANS solver. The work consists of two distinct parts which complement each other, and the purpose is to improve the free surface interface sharpness and to reduce numerical diffusion of the gravity waves. LÄS MER
3. Assessment and Some Improvements of Hybrid RANS-LES Methods
Sammanfattning : Motivated by numerical analysis of a shock/boundary-layer interacting (SBLI) flow in a duct, where some typical existing hybrid RANS-LES methods become awkward to give accurate predictions of the shock-induced corner separation bubble, a new hybrid RANS-LES method, has been proposed. The model is based on a low-Reynolds-number (LRN) $k-\omega$ RANS model, which is one of the few models that are capable of giving reasonable predictions for the SBLI flow in RANS computations. LÄS MER
4. Efficient Full-Scale CFD for Ship Hydrodynamics
Sammanfattning : An efficient numerical approach for ship hydrodynamics, involving a hybrid free-surface potential flow/RANS method, is explored. The work focuses on estimating the delivered power of ships in calm water and in waves, highlighting the benefits of full-scale simulations, particularly for ships with Energy Saving Devices. LÄS MER
5. Analytical and Numerical Studies of Internal Swirling Flows
Sammanfattning : Swirling flows are common in technical applications, e.g. turbines, pumps, fans, compressors and combustors. LÄS MER