Numerical Simulation of Aerodynamic Losses of Nozzle Guide Vanes

2019 ◽  
Author(s):  
◽  
Kynan Schilling
Keyword(s):  
Numerical Simulation ◽  
Guide Vanes ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Aerodynamic Losses

Characteristics of Volcanic Ash in a Gas Turbine Combustor and Nozzle Guide Vanes

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Lei-Yong Jiang ◽  
Yinghua Han ◽  
Prakash Patnaik
Keyword(s):  
Gas Turbine ◽  
Volcanic Ash ◽  
Inlet Temperature ◽  
Gas Turbine Combustor ◽  
Flow Passage ◽  
Guide Vanes ◽  
Cooling Flow ◽  
Cooling Passage ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

To understand the physics of volcanic ash impact on gas turbine hot-components and develop much-needed tools for engine design and fleet management, the behaviors of volcanic ash in a gas turbine combustor and nozzle guide vanes (NGV) have been numerically investigated. High-fidelity numerical models are generated, and volcanic ash sample, physical, and thermal properties are identified. A simple critical particle viscosity—critical wall temperature model is proposed and implemented in all simulations to account for ash particles bouncing off or sticking on metal walls. The results indicate that due to the particle inertia and combustor geometry, the volcanic ash concentration in the NGV cooling passage generally increases with ash size and density, and is less sensitive to inlet velocity. It can reach three times as high as that at the air inlet for the engine conditions and ash properties investigated. More importantly, a large number of the ash particles entering the NGV cooling chamber are trapped in the cooling flow passage for all four turbine inlet temperature conditions. This may reveal another volcanic ash damage mechanism originated from engine cooling flow passage. Finally, some suggestions are recommended for further research and development in this challenging field. To the best of our knowledge, it is the first study on detailed ash behaviors inside practical gas turbine hot-components in the open literature.

Forced responses on a radial turbine with nozzle guide vanes

2014 ◽  
Vol 23 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Yixiong Liu ◽  
Ce Yang ◽  
Chaochen Ma ◽  
DaZhong Lao
Keyword(s):  
Guide Vanes ◽  
Radial Turbine ◽  
Nozzle Guide ◽  
Forced Responses ◽  
Nozzle Guide Vanes

Degradation of Aerodynamic Performance of an Intermediate-Pressure Steam Turbine Due to Erosion of Nozzle Guide Vanes and Rotor Blades

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Koichi Yonezawa ◽  
Tomoki Kagayama ◽  
Masahiro Takayasu ◽  
Genki Nakai ◽  
Kazuyasu Sugiyama ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Steam Turbine ◽  
Rotor Blade ◽  
Rotor Blades ◽  
Flow Angle ◽  
Guide Vanes ◽  
Intermediate Pressure ◽  
Pressure Steam ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

Deteriorations of nozzle guide vanes (NGVs) and rotor blades of a steam turbine through a long-time operation usually decrease a thermal efficiency and a power output of the turbine. In this study, influences of blade deformations due to erosion are discussed. Experiments were carried out in order to validate numerical simulations using a commercial software ANSYS-cfx. The numerical results showed acceptable agreements with experimental results. Variation of flow characteristics in the first stage of the intermediate pressure steam turbine is examined using numerical simulations. Geometries of the NGVs and the rotor blades are measured using a 3D scanner during an overhaul. The old NGVs and the rotor blades, which were used in operation, were eroded through the operation. The erosion of the NGVs leaded to increase of the throat area of the nozzle. The numerical results showed that rotor inlet velocity through the old NGVs became smaller and the flow angle of attack to the rotor blade leading edge became smaller. Consequently, the rotor power decreased significantly. Influences of the flow angle of at the rotor inlet were examined by parametric calculations and results showed that the angle of attack was an important parameter to determine the rotor performance. In addition, the influence of the deformation of the rotor blade was examined. The results showed that the degradation of the rotor performance decreased in accordance with the decrease of blade surface area.

Validation and Comparison of Strip Seal Designs for Gas Turbine Engine Nozzle Guide Vanes

2008 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Gas Turbine Engine ◽  
Experimental Comparison ◽  
Cfd Modelling ◽  
Guide Vanes ◽  
Turbine Engine ◽  
Seal Design ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

Strip seals are commonly used to prevent or limit leakage flows between nozzle guide vanes (NGV) and other gas turbine engine components that are assembled from individual segments. Leakage flow across, for example, a nozzle guide vane platform, leads to increased demands on the gas turbine engine internal flow system and a rise in specific fuel consumption (SFC). Careful attention to the flow characteristics of strip seals is therefore necessary. The very tight tolerances associated with strip seals provides a particular challenge to their characterisation. This paper reports the validation of CFD modelling for the case of a strip seal under very carefully controlled conditions. In addition, experimental comparison of three types of strip seal design, straight, arcuate, and cloth, is presented. These seals are typical of those used by competing manufacturers of gas turbine engines. The results show that the straight seal provides the best flow sealing performance for the controlled configuration tested, although each design has its specific merits for a particular application.

Failure Analysis of Heavy Industrial Gas Turbine Engine First Stage Nozzel Guide Vane

2012 ◽  
Vol 445 ◽  
pp. 1047-1052
Author(s):  
Alaaeldin H. Mustafa
Keyword(s):  
Failure Analysis ◽  
Gas Turbine ◽  
Guide Vane ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Guide Vanes ◽  
X Ray ◽  
Nozzle Guide ◽  
Industrial Gas Turbine ◽  
Nozzle Guide Vanes

Failure analysis investigation was conducted on 70 MW set of 1st stage turbine nozzle guide vanes (NGVs) of heavy industrial gas turbine. The failure was investigated using the light optical microscope (LOM), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDS) in an environmental scanning electron microscope (ESEM). The results of the analysis indicate that the NGVs which were made of Co base superalloy FSX-414 had been operated above the recommended operating hours under different fuel types in addition to inadequate repair process in previous repair removal. The XRD analysis of the fractured areas sample shows presence ofwhich might indicate the prolonged operation at high temperature. Keywords: cobalt-base; nozzle guide vanes, gas turbine.

Nozzle Guide Vane Static Strip Seals

2006 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Turbines ◽  
Guide Vane ◽  
Main Stream ◽  
Guide Vanes ◽  
Advantages And Disadvantages ◽  
Air System ◽  
Improved Performance ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Assembly Constraints

Sealing of components where there is no relative motion between the elements concerned remains a significant challenge in many gas turbine engine applications. Loss of sealing and cooling air from the internal air system through seals impacts on specific fuel consumption and can lead to undesirable flow interactions with resultant cost implications. For gas turbines, various strip seal types have been developed for use between Nozzle Guide Vanes in order to limit the flow of gas between the main stream annulus and the internal air system. Many different types of design have been proposed for overcoming strip seal problems such as misalignment of the grooves due to manufacturing and assembly constraints. In this paper various methods, with a particular focus on patents, for minimising the amount of leakage caused by such problems for strip seals between nozzle guide vanes are reviewed. By considering the advantages and disadvantages of each technique it is concluded that although apparently new strip seal designs for NGVs have improved performance, none of them can be considered to be ideal. This paper reviews the techniques and makes recommendations for future designs.

Film Cooling Research on the Endwall of a Turbine Nozzle Guide Vane in a Short Duration Annular Cascade: Part 1—Experimental Technique and Results

1992 ◽  
Vol 114 (4) ◽  
pp. 734-740 ◽  
Author(s):  
S. P. Harasgama ◽  
C. D. Burton
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Guide Vane ◽  
Density Ratio ◽  
Suction Side ◽  
Coolant Temperature ◽  
Guide Vanes ◽  
Nozzle Guide ◽  
Annular Cascade ◽  
Nozzle Guide Vanes

Heat transfer and aerodynamic measurements have been made on the endwalls of an annular cascade of turbine nozzle guide vanes in the presence of film cooling. The results indicate that high levels of cooling effectiveness can be achieved on the endwalls of turbine nozzle guide vanes (NGV). The NGV were operated at the correct engine nondimensional conditions of Reynolds number, Mach number, gas-to-wall temperature ratio, and gas-to-coolant density ratio. The results show that the secondary flow and horseshoe vortex act on the coolant, which is convected toward the suction side of the NG V endwall passage. Consequently the coolant does not quite reach the pressure side/casing trailing edge, leading to diminished cooling in this region. Increasing the blowing rate from 0.52 to 1.1 results in significant reductions in heat transfer to the endwall. Similar trends are evident when the coolant temperature is reduced. Measured heat transfer rates indicate that over most of the endwall region the film cooling reduces the Nusselt number by 50 to 75 percent.

scholarly journals Investment casting of nozzle guide vanes from nickel-based superalloys: part II – grain structure prediction

2014 ◽  
Vol 3 (1) ◽  
pp. 369-384 ◽  
Author(s):  
Agustin Jose Torroba ◽  
Ole Koeser ◽  
Loic Calba ◽  
Laura Maestro ◽  
Efrain Carreño-Morelli ◽  
...  
Keyword(s):  
Investment Casting ◽  
Structure Prediction ◽  
Grain Structure ◽  
Guide Vanes ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

scholarly journals Technical Feasibility of Laser Dissimilar Welding of Superalloys on Casted Nozzle Guide Vanes

Procedia CIRP ◽  
2016 ◽  
Vol 41 ◽  
pp. 963-968 ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Vincenzo Sergi ◽  
Andrea Tartaglia ◽  
Michele Di Foggia ◽  
...  
Keyword(s):  
Dissimilar Welding ◽  
Technical Feasibility ◽  
Guide Vanes ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes
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