In recent years two general methods for flow analysis in turbomachinery have been developed, one generally called the Streamline Curvature Method, the other the Matrix Through-Flow Method. Both methods solve the same flow equations but the differences in technique introduce different operational constraints and difficulties. A comparative assessment of the relative merits of the two methods has been difficult because the various authors did not use similar cascade models to represent cascade loss and deviation, a necessary adjunct to each technique. This paper outlines the two methods, and a common cascade model for both, and compares two programs written to implement the two techniques for ease of use, computer time and storage requirements, flexibility and inherent limitations. The programs are used to compute the flow field in three axial flow compressor applications: an interconnecting duct, a transonic fan, and three stage axial compressor. The predicted performance for the above machines was fairly good, although no attempt was made to “tune” the cascade model for the specific type of machine, as the relative merits of each method were of interest. It is concluded that there is a small operational advantage to the matrix method.

Computational Fluid Dynamics (CFD) plays an ever increasingly important role in the design and analysis of racing sailboats and in particular America's Cup yachts. The pervasiveness of CFD in the design process is demonstrated by a wide range of applications, concentrating on hull and underwater appendage design, from two of the US syndicate entries, Young America and AmericaOne, from just completed America's Cup 2000 races in Auckland, NZ. The CFD methods employed generally span a wide range, but the freesurface panel method SPLASH and the overset NavierStokes code Overflow are highlighted here. Discussion includes the CFD tools employed, how they are made to fit into the design process, and specific applications directed at hull and appendage design.

An integral entrainment computation technique is presented for the three-dimensional boundary-layer growth on the stationary end-walls of centrifugal turbomachinery. The analytical model assumes axisymmetric inviscid core flow and viscous flow in the wall region, and the interaction between the two layers is considered. A novel form of the three-dimensional boundary-layer equations is presented. The form is physically appealing for this axisymmetric application and provides distinct advantages in the prediction of boundary-layer growth. It is demonstrated that it is essential to use the meridional boundary-layer profile to compute the Head entrainment function for this type of flow, as opposed to the streamwise velocity profile, as is more commonly done. Comparison with experimental measurements shows good agreement in the integral parameters. In addition, good agreement with experimental velocity profiles was achieved for a separating and reattaching flow.

There has been an increased concentration of effort recently in the understanding of the complex flow in centrifugal turbomachines, especially industrial machines. Although it is impossible at this time, to model all the phenomena existing in a real machine, it is felt that a systematic approach which makes use of recent advances in computational fluid dynamics, and extends these as further developments occur, will significantly improve our understanding of the flow, and our ability to predict performance and improve efficiency. In this paper, a new general finite difference technique for solving the flow field in the hub-to-shroud plane of any component of a centrifugal turbomachine is described. The technique uses a quasi-orthogonal finite-difference net, and solves the resulting system of equations using a matrix method. Thus the technique offers a stable, accurate computational method, combined with a fixed grid which may be simply applied to the most complex annular passage shape. The results for three numerical examples are presented, a radial to axial inlet, a vaneless radial diffuser and an interstage return bend.

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