Transonic Axial Turbine Stage Research Articles

The efficiency of a pulsed detonation combustor–axial turbine integration

The paper presents a detailed numerical investigation of a pulsed detonation combustor (PDC) coupled with a transonic axial turbine stage. The time-resolved numerical analysis includes detailed chemistry to replicate detonation combustion in a stoichiometric hydrogen–air mixture, and it is fully coupled with the turbine stage flow simulation. The PDC–turbine performance and flow variations are analyzed for different power input conditions, by varying the system purge fraction. Such analysis allows for the establishment of cycle averaged performance data and also to identify key unsteady gas dynamic interactions occurring in the system. The results obtained allow for a better insight on the source and effect of different loss mechanisms occurring in the coupled PDC–turbine system. One key aspect arises from the interaction between the non-stationary PDC outflow and the constant rotor blade speed. Such interaction results in pronounced variations of rotor incidence angle, penalizing the turbine efficiency and capability of generating a quasi-steady shaft torque.

Finite Volume Analysis of Inviscid Interaction for Two-Dimensional Transonic Axial Turbine Stage Using Multi-block Hybrid Grids

Article Finite Volume Analysis of Inviscid Interaction for Two-Dimensional Transonic Axial Turbine Stage Using Multi-block Hybrid Grids was published on September 1, 2002 in the journal International Journal of Turbo & Jet-Engines (volume 19, issue 3).

On the choice of variables and matching criteria for the steady simulation of transonic axial turbine stages

A transonic axial turbine stage is computed by solving the time-averaged Navier-Stokes equations in the turbulent flow regime. The stator and rotor rows are interfaced using a mixing plane. The sensitivity of the stator-rotor coupling to the boundary conditions and mixing strategies is investigated. The mass or area tangential averaging is found to have slight impact on the stator-rotor match. The relative and absolute formulation of the rotor inlet boundary condition is found to alter the match of the two rows. The computations indicate that both relative and absolute boundary conditions should be used to estimate and control part of the uncertainty in the stator-rotor match, which can be greatly reduced by an iterative procedure, based on the stator exit pressure. The area averaging allows a unique matching point to be estimated for both absolute and relative properties.

Calculation of the Three-Dimensional, Steady, Inviscid Flow in a Transonic Axial Turbine Stage

The aim of this paper is to develop an approach to compute the three-dimensional, rotational, adiabatic, inviscid flow of a perfect gas in a transonic axial turbine stage. The time-dependent Euler equations, expressed in a cylindrical coordinate system, are solved using a time-marching method and a finite volume approach. The absolute flow is calculated in the stator, whereas the relative flow is computed in the rotor. A time-averaged blade row interaction is assumed. The method is applied to a transonic single-stage turbine. The calculated results agree well with the measured performance and three-dimensional aspects of the flow appear clearly.