Experimental investigations directed towards improving the performance of a biplane Wells turb1ne for wave power generator are reported. Tested are three turbine configurat1ons cons1stlng of (1) biplane rotor with outer guide vanes, (2) biplane rotor with inner guide vanes, (3) triplane rotor. The results have been compared from the viewpoints of starting characteristics, running characteristics and stall margin. Most of the configurations tested have shown improvements in the operation range mainly by postponement of stall. The best configuration is the biplane turbine with outer guide vanes from a viewpoint of overall characteristics, for which a suitable choice of design factors has been suggested.
The self rectifying Wells air turbine is a simple and efficient turbine for energy conversion from wave energy devices of oscillating water/air column type. To utilize more available energy the pressure drop across the Wells rotor should match with the available pressure drop in the oscillating column. When the ava1lable pressure drop is more than the pressure which a Wells turbine can accommodate for its efficient operation, a multiplane Wells turbine is adopted (Grant, et al., 1980, Raghunathan, et al., 1983, Inoue, et al., 1986a). According to these results, a biplane Wells turbine can accommodate twice the pressure drop of a monoplane Wells turbine w1th a small sacrifice in peak efficiency, and can operate over a wider range of flow rates without stall. In addition to the advantage, it is also reported by Inoue, et al.(1986a) that the biplane Wells turbine has a better starting characteristics and stall margin than a monoplane Wells turbine. This paper includes experimental investigations directed towards improving the performance of the biplane Wells turbine. Several configurations of model turbine have been tested: these are
biplane turbine with outer guide vanes,
biplane turbine with inner guide vanes,