Time-Accurate Three-Dimensional Navier-Stokes Analysis of One-and-One-Half Stage Axial-Flow Turbine

Anew three-dimensionalNavier–Stokesmethod for the analysisof the unsteady  ow inmultiple turbomachinery blade rows is presented. To take into account turbulent effects, a low-Reynolds-numberk–2model is used. Smooth wave propagationaccross the sliding rotor/stator interfaces is accomplished with a fully conservative interface  ux algorithm. The use of physically motivated time-step scales is enabled by an implicit relaxation strategy, where Newton subiterations are applied to provide time accuracy. The code system is validated for a one-and-one-halfstage axial- ow turbine, which is documented as an ERCOFTAC SIG test case. Detailed experimental data are exploited to evaluate the predictive capability of the code. The analysis focuses on typical unsteady effects such as negative jets in the wakes, general effects of unsteadiness, as well as the representation and the unsteady generation of losses.