The Application of Non-axisymmetric Endwall Contouring in a Single Stage, Rotating Turbine

Snedden, G; Dunn, D; Ingram, GL; Gregory-Smith, DG

Abstract

As turbine manufacturers strive to develop machines that are more efficient, one area of focus has been the control of secondary flows. To a large extent these methods have been developed through the use of computational fluid dynamics and detailed measurements in linear and annular cascades and proven in full scale engine tests. This study utilises 5-hole probe measurements in a low speed, model turbine in conjunction with computational fluid dynamics to gain a more detailed understanding of the influence of a generic endwall design on the structure of secondary flows within the rotor. This work is aimed at understanding the influence of such endwalls on the structure of secondary flows in the presence of inlet skew, unsteadiness and rotational forces. Results indicate a 0.4% improvement in rotor efficiency as a result of the application of the generic non-axisymmetric endwall contouring. CFD results indicate a clear weakening of the cross passage pressure gradient, but there are also indications that custom endwalls could further improve the gains. Evidence of the influence of endwall contouring on tip clearance flows is also presented.

Citation

Snedden, G., Dunn, D., Ingram, G., & Gregory-Smith, D. (2009). The Application of Non-axisymmetric Endwall Contouring in a Single Stage, Rotating Turbine.

• Conference Name: Proceedings of ASME Turbo Expo 2009: Power for Land, Sea and Air
• Conference Location: Orlando, Florida, USA
• Publication Date: 2009-06
• Publisher: American Society of Mechanical Engineers
• Volume: GT2009-59169