An Experimental Analysis of Flow Through Annular Diffuser With and Without Struts

2006 ◽  
Author(s):  
R. Prakash ◽  
P. Sudhakar ◽  
N. V. Mahalakshmi
Keyword(s):  
Gas Turbine ◽  
Static Pressure ◽  
Structural Members ◽  
Pressure Development ◽  
Annular Diffuser ◽  
Fundamental Research ◽  
Flow Through ◽  
Gas Turbine Exhaust ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

This paper presents the static pressure development and the effect of struts on the performance of an annular diffuser. A typical exhaust diffuser of an industrial gas turbine is annular with structural members, called struts, which extend radially from the inner to the outer annulus wall. An annular diffuser model, primarily intended for fundamental research, has been tested on a wind tunnel. Similar conditions that prevail in an industrial gas turbine have been generated in the diffuser. Measurements were made using a five holed Pitot probe. The research had been carried out to make a detailed investigation on the effect of struts and to advance computational and design tools for gas turbine exhaust diffusers.

CFD Analysis of Industrial Gas Turbine Exhaust Diffusers

2002 ◽  
Author(s):  
V. Vassiliev ◽  
S. Irmisch ◽  
S. Florjancic
Keyword(s):  
Gas Turbine ◽  
Measurement Data ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Cfd Modelling ◽  
Gas Turbine Exhaust ◽  
Key Aspects ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

The key aspects for the reliable CFD modelling of exhaust diffusers are addressed in this paper. In order to identify adequate turbulence models a number of 2D diffuser configurations have been simulated using different turbulence models and results have been compared with measurements. An automated procedure for a time- and resource-efficient and accurate prediction of complex diffuser configuration is presented. The adequate definitions of boundary conditions for the diffuser simulation using this procedure are discussed. In the second part of this paper, the CFD procedure is being applied to investigate the role of secondary flow on axial diffusers. Prediction results are discussed and compared with available measurement data.

OPTIMIZING CERAMIC KILN OPERATION UTILIZING INDUSTRIAL GAS TURBINE EXHAUST GASES

Clean Air ◽  
2004 ◽  
Vol 5 (3) ◽  
pp. 243-266
Author(s):  
L. M. Fletcher ◽  
D. K. Iatridis ◽  
A. N. Katsanevakis ◽  
A. A. Lappas ◽  
O. Monachos ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Exhaust Gases ◽  
Gas Turbine Exhaust ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

Aerodynamic Design and Experimental Study of Marine Gas Turbine Exhaust Volutes

1981 ◽  
Author(s):  
Lu Xingsu ◽  
Pan Kunyuan ◽  
Wu Zuomin
Keyword(s):  
Gas Turbine ◽  
Exhaust System ◽  
Aerodynamic Characteristics ◽  
Basic Design ◽  
Aerodynamic Design ◽  
Engine Room ◽  
Annular Diffuser ◽  
Gas Turbine Exhaust ◽  
Selection Of ◽  
Turbine Exhaust

The aerodynamic characteristics of the exhaust system have an important bearing on the economic aspects of the marine gas turbine. The exhaust volute is an important component of the exhaust system. The design of turbine exhaust volutes must take into account the structural demands of the gas turbine, the layout of the exhaust system as a whole in the engine room and the hull as well as its overall dimension requirements. This paper discusses the design principles of exhaust volutes. Given the hub-tip ratio dl/D1 of turbine exit (volute entry), a method is developed to rationally select the axial length L and radial width B. The selection of an annular diffuser and the relevant parameters along with the coordination of diffuser and collector are analyzed. On the basis of an analysis of experimental data the basic design criteria of exhaust volutes are proposed.

Study of Gas Turbine Exhaust Diffuser Performance and Its Enhancement by Shape Modifications

2010 ◽  
Author(s):  
A. M. Pradeep ◽  
Bhaskar Roy ◽  
V. Vaibhav ◽  
D. Srinuvasu
Keyword(s):  
Gas Turbine ◽  
Leading Edge ◽  
Recovery Coefficient ◽  
Performance Improvements ◽  
Flow Swirl ◽  
Conical Diffuser ◽  
Annular Diffuser ◽  
Significant Performance ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

In this paper, results of studies on typical gas turbine exhaust diffuser geometry have been reported. This diffuser consists of an annular diffuser followed by a conical diffuser. The annular diffuser has 5 radial, backward swept struts. The studies were carried out at a Reynolds number of 7.7 × 105 based on the diffuser inlet diameter (hydraulic). Two inflow boundary conditions corresponding to (i) full load (low swirl) and (ii) part load (high swirl) operations of a typical gas turbine exit were separately simulated. The performance of the diffuser was assessed in terms of total pressure loss and static pressure recovery coefficient along the diffuser. It was observed that the baseline diffuser geometry had substantial losses owing to separation of the boundary layer, beginning as early as in the annular diffuser and continuing all the way up to the exit of the conical diffuser. The performance was found to worsen with higher inlet swirl. It was observed that the divergence angle in the annular part of the diffuser plays an important role in the initiation of flow separation. Interaction of inlet flow swirl with the struts also initiates considerable asymmetry in the flow pattern within the conical diffuser. Based on observations from the baseline geometry, several new annular diffuser geometries with different divergence angles and shapes were numerically studied. The shroud shapes were manipulated at specific locations like the plane of the strut leading edge, maximum airfoil thickness and the trailing edge of the struts. Significant performance improvements were observed in these simulated diffuser configurations. Two such annular diffuser geometries have been discussed in detail in this paper.

Cast Iron-Nickel Alloy for Industrial Gas Turbine Engine Applications

2005 ◽  
Author(s):  
Jeffrey R. Neyhouse ◽  
Jose M. Aurrecoechea ◽  
J. Preston Montague ◽  
John D. Lilley
Keyword(s):  
Gas Turbine ◽  
Ductile Iron ◽  
Gas Turbine Engine ◽  
Austenitic Steels ◽  
Nickel Steel ◽  
Turbine Engine ◽  
Gas Turbine Exhaust ◽  
Nodular Graphite ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

Austenitic ductile iron castings have traditionally been used for gas turbine exhaust components that require castability, good machinability, low thermal expansion, and high strength at elevated temperatures. The achievement of optimum properties in austenitic ductile irons hinges on the ability of the foundry to produce nodular graphite in the microstructure throughout the component. In large, complex components, consistently producing nodular graphite is challenging. A high-nickel steel alloy that is suitable for sand castings has been recently developed for industrial gas turbine engine applications. The alloy exhibits similar mechanical and physical properties to austenitic ductile irons, but with improved processability and ductility. This alloy is weldable and exhibits no secondary graphite phase. This paper presents the results of a characterization program conducted on a 35% nickel, high-alloy steel. The results are compared with an austenitic ductile iron of similar composition. Tensile and creep properties from ambient temperature to 760°C (1400°F) are included, along with fabrication experience gained during the manufacture of several sand cast components at Solar Turbines Incorporated. The alloy has been successfully adopted for gas turbine exhaust system components and other applications where austenitic ductile irons have traditionally been utilized. The low carbon content of austenitic steels permits improved weldabilty and processing characteristics over austenitic ductile irons. The enhancements provided by the alloy indicate that additional applications, as both austenitic ductile iron replacements and new components, will arise in the future.

Effects of struts profiles and skewed angles on the aerodynamic performance of gas turbine exhaust diffuser

2021 ◽  
pp. 095765092098520
Author(s):  
Yuxuan Dong ◽  
Zhigang Li ◽  
Jun Li ◽  
Liming Song
Keyword(s):  
Gas Turbine ◽  
Static Pressure ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Pressure Recovery ◽  
Recovery Coefficient ◽  
Flow Field Characteristics ◽  
Gas Turbine Exhaust ◽  
Pressure Recovery Coefficient ◽  
Turbine Exhaust

The strut structure directly affects the flow field characteristics and aerodynamic performance of the gas turbine exhaust diffuser. The effects of the strut profiles and strut skewed angles on the aerodynamic performance of the exhaust diffuser at different inlet pre-swirls were numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes(RANS) and Realizable k-ε turbulence model. The numerical static pressure recovery coefficient of the exhaust diffuser is in agreement with the experimental data well. The reliability of the numerical method for the exhaust diffuser performance analysis was demonstrated. Exhaust diffusers with four kinds of vertical strut profiles obtain the highest static pressure recovery coefficient at the inlet pre-swirl of 0.35. The similar static pressure recovery coefficient of exhaust diffusers with four kinds of vertical strut airfoils are observed when the inlet pre-swirl is less than 0.48. The static pressure recovery coefficient of exhaust diffusers with vertical b1 and b2 struts are higher than that with the a1 and a2 struts when the inlet pre-swirl is greater than 0.48. At the inlet pre-swirl of 0.35, The static pressure recovery coefficient of the exhaust diffuser with the a1 strut decreases with the increasing of the strut skewed angles. The static pressure recovery coefficient of the exhaust diffuser with the b1 strut increases with the increasing of the strut skewed angles, and the static pressure recovery coefficient increases by 3.6% compared with the vertical design when the skewed angle of b1 strut is 40[Formula: see text]. At the inlet pre-swirl of 0.64. The static pressure recovery coefficient of the exhaust diffuser with the a1 strut increases by 8.7% compared with the vertical design when the skewed angle of a1 strut is greater than 20°. In addition, the static pressure recovery coefficient of the exhaust diffuser with the b1 strut decreases by 3.8% compared with the vertical design when the skewed angle of b1 strut is 40°. The method to improve the aerodynamic performance of the exhaust diffuser by appropriate increase the strut maximum thickness and design the strut skewed angle is proposed in this work.

scholarly journals Flow Distribution in a Model Recuperator of an Intercooled-Recuperative Marine Gas Turbine

1990 ◽  
Author(s):  
Robert A. Uhlig ◽  
Robert L. Kiang ◽  
Janet L. Buyer
Keyword(s):  
Gas Turbine ◽  
Power Level ◽  
Flow Distribution ◽  
Brayton Cycle ◽  
Velocity Measurements ◽  
Turbine Engine ◽  
Flow Through ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust ◽  
Engine Power

An intercooled-recuperative Brayton cycle is known to have a significantly higher thermal efficiency and hence a lower specific fuel consumption. The success of an ICR gas turbine engine, however, depends heavily on the performance of the recuperator. Uniform flow leading into the recuperator is usually assumed in the recuperator design. This experimental work represents an initial effort to understand and to improve the flow distribution in a marine gas turbine exhaust diffuser/recuperator configuration. Velocity measurements immediately downstream of the recuperator show that the flow through the recuperator is nonuniform; but the nonuniform flow distribution remains invariant with respect to the engine power level.

scholarly journals Flow Field Measurements in an Annular Gas Turbine Exhaust Diffuser With Struts

1999 ◽  
Author(s):  
Umberto Desideri ◽  
Stefano Ubertini
Keyword(s):  
Gas Turbine ◽  
Field Measurements ◽  
Axial Direction ◽  
Mean Velocity ◽  
Measuring Point ◽  
Turbulence Characteristics ◽  
Inlet Velocity ◽  
Annular Diffuser ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

This paper presents the velocity and turbulence characteristics of the flow in an annular diffuser, which is a model of a gas turbine exhaust diffuser with six struts. The diffuser where the measurements were made is a scaled down model of a 10 MW gas turbine, built by GE/Nuovo Pignone. In a previous paper (Desideri and Manfrida, 1995) 2-D turbulence and velocity measurements were presented with axial inlet velocity conditions. In this paper a more detailed 3-D analysis of the design and off design behavior of the diffuser is presented. Turbulence characteristics were determined by means of two hot split-film probes, which allowed measuring axial, radial and tangential components of the mean velocity and their fluctuating components. The measuring point is moved inside the diffuser by means of two step-motors, which allow the rotation of the hub and the radial displacement of the probe. Off-design behavior of the annular diffuser was determined by changing the inlet velocity angle of 10° from axial direction. The effect of swirl on the performance of the diffuser will be presented. Turbulence microscales were also calculated in regions of interest inside the diffuser, with particular attention to the strut wake.

Acoustic Characteristics of a Gas Turbine Exhaust Model

1974 ◽  
Vol 96 (3) ◽  
pp. 181-184 ◽  
Author(s):  
J. R. Cummins
Keyword(s):  
Gas Turbine ◽  
Acoustic Radiation ◽  
Flow Path ◽  
Scale Model ◽  
Temperature Ratio ◽  
Acoustic Characteristics ◽  
Gas Turbine Exhaust ◽  
Acoustical Data ◽  
Turbine Exhaust

To investigate the sources of acoustic radiation from a gas turbine exhaust, a one-seventh scale model has been constructed. The model geometrically scales the flow path downstream of the rotating parts including support struts and turning vanes. A discussion and comparison of different kinds of aerodynamic and acoustic scaling techniques are given. The effect of the temperature ratio between model and prototype is found to be an important parameter in comparing acoustical data.

Prediction of Pressure Rise in a Gas Turbine Exhaust Duct Under Flameout Scenarios While Operating On Hydrogen and Natural Gas Blends

2021 ◽  
Author(s):  
Orlando Ugarte ◽  
Suresh Menon ◽  
Wayne Rattigan ◽  
Paul Winstanley ◽  
Priyank Saxena ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Model ◽  
Computational Domain ◽  
Cfd Model ◽  
Exhaust Duct ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Abstract In recent years, there is a growing interest in blending hydrogen with natural gas fuels to produce low carbon electricity. It is important to evaluate the safety of gas turbine packages under these conditions, such as late-light off and flameout scenarios. However, the assessment of the safety risks by performing experiments in full-scale exhaust ducts is a very expensive and, potentially, risky endeavor. Computational simulations using a high fidelity CFD model provide a cost-effective way of assessing the safety risk. In this study, a computational model is implemented to perform three dimensional, compressible and unsteady simulations of reacting flows in a gas turbine exhaust duct. Computational results were validated against data obtained at the simulated conditions in a representative geometry. Due to the enormous size of the geometry, special attention was given to the discretization of the computational domain and the combustion model. Results show that CFD model predicts main features of the pressure rise driven by the combustion process. The peak pressures obtained computationally and experimentally differed in 20%. This difference increased up to 45% by reducing the preheated inflow conditions. The effects of rig geometry and flow conditions on the accuracy of the CFD model are discussed.

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