Investigation on Variable Guide Vane (VGV) Unsteady Flow Characteristic of Axial Turbine

Numerical Study on the Internal Flow Field of a Reversible Turbine during Continuous Guide Vane Closing

The unsteady flow field in a reversible pump-turbine is investigated during the continuous load rejection using a 3D computational fluid dynamic analysis. Numerical calculations are carried out using the detached eddy simulation (DES) turbulence model and a new approach involving automatic mesh motion. In this way, the instability of the flow field is analyzed by continuously changing the guide...

Flow and Thermal Performance of a Gas Turbine Nozzle Guide Vane with a Leading Edge Fillet

Complex three-dimensional vortex flows develop at the junction of a gas turbine airfoil and its casing (endwall). These flows increase the transfer of heat from the combustion gases to the metal parts and contribute to reduced aerodynamic efficiency. Past studies have shown that the use of a large fillet at the airfoil-endwall junction can reduce or eliminate the endwall vortex flow pattern. To...

Flow and Thermal Performance of an Airfoil-endwall Fillet for a Gas Turbine Nozzle Guide Vane

Gas turbine engines are used in a variety of power generation applications, including providing thrust for the F-35 Lightning II Joint Strike Fighter, turning electrical generators in combined-cycle power plants, and powering the M1 Abrams Main Battle Tank. In the high-temperature region of the turbine section, a complex vortical (swirling) flow present near the junction of a turbine airfoil an...

Modelling a Tidal Turbine in Unsteady Flow

A brief review of the literature is provided on the characteristics of marine currents and the approaches used for simulating tidal turbines. The feasibility of using CFD models to simulate time-dependent turbulent flow around a tidal turbine is then explored. Two different approaches for specifying the structure of the turbulent inflow conditions in CFD models are compared: the von Kármán spec...

Blade-loading effects on the propagation of unsteady flow and on forcing functions in axial-turbine cascades