High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the m...

This paper presents a robust crack detection algorithm for wind turbine blades using vibroacoustic modulation and the area under the curve of the frequency spectrum of the sidebands. In a previous paper it was shown how the operational vibration of the turbine could be used as a pumping signal in vibro-acoustic modulation. However, the sources of the operational vibration frequencies are many a...

(2006) Laser-optical investigation of stator-rotor interaction in a transonic turbine, 1 ABSTRACT This paper presents research in a highly-loaded cold-flow transonic turbine under continuous and engine like conditions. Special focus was placed on blade row interaction at app. 10600 rpm. While the first step was the investigation of a single stage machine (stator-rotor), the second step extended...

This paper presents the results of simulations of the complete three-dimensional fluid flow through the Spiral Casing, Stay Vane, Guide Vane, and then through the Francis turbine runner of the Derbendikan power station. To investigate the flow in the Francis turbine and also to identify the loads acting on the turbine blades, a three-dimensional model was prepared according to specifications pr...

To clarify the behavior of the blade tip vortices of a wind turbine equipped with a brimmed-diffuser shroud, called a “Wind-Lens turbine”, we conducted a three-dimensional numerical simulation using a large eddy simulation (LES). Since this unique wind turbine consists of not only rotating blades but also a diffuser shroud with a broad-ring brim at the exit periphery, the flow field around the ...

This work concerns the root-cause investigation of the blade damage in a steam turbine bladed disk of a thermoelectric power plant. The purpose of this work is to investigate the low cycle fatigue problem by determining the natural frequencies and the associated modes of vibrations of a bladed disk and comparing with the operational rotation of the turbine and its harmonics. The bladed disk is ...

Turbine balancing is an important and regular maintenance operation at airline companies. Because of manufacturing inaccuracies, variations occur in the weights of the blades that can, in turn, lead to significant out-of-balance forces on the engine. The overall time required for balancing can be significantly decreased if the best placement of turbine blades is first determined mathematically....

The long-term reliability of tidal turbines is critical if these structures are to be cost effective. Optimized design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades, but there are few data available to predict material behaviour under coupled environmental and cycling loading. The present study addresses this pro...

Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated in a wind tunnel. The duct is shaped using rolling steel sheets on a sloping surface and finally...

Vertical axis wind turbines (VAWT) are an alternative to horizontal axis wind turbines (HAWT) for wind and tidal energy harvesting applications. Studies of vertical axis wind turbines have heavily invested in understanding the behaviour of the complete turbine, but often with only cursory assessment of the contributions of unsteady aerodynamics of individual blades. This paper experimentally ex...