Three-Dimensional Rotational Flow in Transonic Turbomachines: Part II — Full 3D Flow in CAS Rotor Obtained by Using a Number of S1 and S2 Stream Filaments

Abstract

The general theory for three–dimensional flow in subsonic and supersonic turbomachines has recently been extended to transonic turbomachines. In Part II of the paper, quasi– and full three–dimensional solutions of the transonic flow in the CAS rotor are presented. The solutions are obtained by iterative calculation between a number of S1 stream filaments and, respectively, a central S2 stream filament and a number of S2m stream filaments. Relatively simple methods developed recently for solving the transonic flow along S1 and S2 stream filaments are used in the calculation. The three–dimensional flow fields in the CAS rotor obtained by the present method are presented in detail with special emphasis on the converging process for the configuration of the S1 and S2 stream filaments. The three–dimensional flow fields obtained in the quasi– and full 3D solutions are quite similar, but the former gives a lower peak Mach number and a smaller circumferential variation in Mach number than the latter. A comparison between the theoretical solution and the Laser–2–Focus measurement shows that the character of the transonic flow including the 3D shock structure is in good agreement, but the measured velocity is slightly higher than the calculated one over most of the flow field.