Detection and Localization of Fouling in a Gas Turbine Compressor From Aerothermodynamic Measurements

2004 ◽  
Author(s):  
Knox T. Millsaps ◽  
Jon Baker ◽  
Jeffrey S. Patterson
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Total Pressure ◽  
Axial Flow ◽  
Pressure Losses ◽  
Sensitive Parameter ◽  
Influence Coefficients ◽  
Gas Turbine Compressor ◽  
Detection And Localization ◽  
The Impact

This paper presents a new method for condition assessment of axial flow compressors that provides a tool for specifying the magnitude and location of degradation due to fouling. A simple, meanline, stage-stacking analysis is developed, which includes the impact of blade roughness on the mass flow, work coefficient, and efficiency. The performance of a baseline, three-stage compressor with hydrodynamically smooth blades is calculated. Using the baseline geometry, the influence of roughness of the blade surfaces in the front, middle and rear stages are calculated. Empirical data for the increased total pressure losses and greater turning deviation that occurs due to rough blades are used. This analysis indicates that airfoil fouling in different stages, produce characteristic aerothermodynamic signatures, and hence the faults can be localized by the magnitudes of the various influence coefficients. This analysis also predicts that the most sensitive parameter for predicting fouling in the front stages is the percentage change in mass flow and the most sensitive parameter for predicting fouling in the rear stages is the adiabatic efficiency.

Leakage flow analysis in the gas turbine shroud gap

2019 ◽  
Vol 91 (8) ◽  
pp. 1077-1085 ◽  
Author(s):  
Filip Wasilczuk ◽  
Pawel Flaszynski ◽  
Piotr Kaczynski ◽  
Ryszard Szwaba ◽  
Piotr Doerffer ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Mass Flow ◽  
Labyrinth Seal ◽  
Leakage Flow ◽  
Original Design ◽  
Reference Case ◽  
Content Type ◽  
Flow Through ◽  
The Impact

Purpose The purpose of the study is to measure the mass flow in the flow through the labyrinth seal of the gas turbine and compare it to the results of numerical simulation. Moreover the capability of two turbulence models to reflect the phenomenon will be assessed. The studied case will later be used as a reference case for the new, original design of flow control method to limit the leakage flow through the labyrinth seal. Design/methodology/approach Experimental measurements were conducted, measuring the mass flow and the pressure in the model of the labyrinth seal. It was compared to the results of numerical simulation performed in ANSYS/Fluent commercial code for the same geometry. Findings The precise machining of parts was identified as crucial for obtaining correct results in the experiment. The model characteristics were documented, allowing for its future use as the reference case for testing the new labyrinth seal geometry. Experimentally validated numerical model of the flow in the labyrinth seal was developed. Research limitations/implications The research studies the basic case, future research on the case with a new labyrinth seal geometry is planned. Research is conducted on simplified case without rotation and the impact of the turbine main channel. Practical implications Importance of machining accuracy up to 0.01 mm was found to be important for measuring leakage in small gaps and decision making on the optimal configuration selection. Originality/value The research is an important step in the development of original modification of the labyrinth seal, resulting in leakage reduction, by serving as a reference case.

Effect of Divergence Angle on Flow Through Inlet Section of Diffuser of a Gas Turbine Combustion Chamber: The CFD Approach

2006 ◽  
Author(s):  
Digvijay B. Kulshreshtha ◽  
S. A. Channiwala ◽  
Jitendra Chaudhary ◽  
Zoeb Lakdawala ◽  
Hitesh Solanki ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Total Pressure ◽  
Divergence Angle ◽  
Velocity Head ◽  
Turbine Engine ◽  
Inlet Velocity ◽  
Pressure Losses ◽  
Flow Through ◽  
Mach Numbers

In the combustor inlet diffuser section of gas turbine engine, high-velocity air from compressor flows into the diffuser, where a considerable portion of the inlet velocity head PT3 − PS3 is converted to static pressure (PS) before the airflow enters the combustor. Modern high through-flow turbine engine compressors are highly loaded and usually have high inlet Mach numbers. With high compressor exit Mach numbers, the velocity head at the compressor exit station may be as high as 10% of the total pressure. The function of the diffuser is to recover a large proportion of this energy. Otherwise, the resulting higher total pressure loss would result in a significantly higher level of engine specific fuel consumption. The diffuser performance must also be sensitive to inlet velocity profiles and geometrical variations of the combustor relative to the location of the pre-diffuser exit flow path. Low diffuser pressure losses with high Mach numbers are more rapidly achieved with increasing length. However, diffuser length must be short to minimize engine length and weight. A good diffuser design should have a well considered balance between the confliction requirements for low pressure losses and short engine lengths. The present paper describes the effect of divergence angle on diffuser performance for gas turbine combustion chamber using Computational Fluid Dynamic Approach. The flow through the diffuser is numerically solved for divergence angles ranging from 5 to 25°. The flow separation and formation of wake regions are studied.

Aerodynamic Performance Evaluation of Axial Flow Fan Using Numerical Techniques

2021 ◽  
Author(s):  
Raghuvaran D. ◽  
Satvik Shenoy ◽  
Srinivas G
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Total Pressure ◽  
Axial Flow ◽  
High Mass ◽  
Ansys Fluent ◽  
Industrial Sectors ◽  
Mass Flow Rates

Abstract Axial flow fans (AFF) are extensively used in various industrial sectors, usually with flows of low resistance and high mass flow rates. The blades, the hub and the shroud are the three major parts of an AFF. Various kinds of optimisation can be implemented to improve the performance of an AFF. The most common type is found to be geometric optimisation including variation in number of blades, modification in hub and shroud radius, change in angle of attack and blade twist, etc. After validation of simulation model and carrying out a grid independence test, parametric analysis was done on an 11-bladed AFF with a shroud of uniform radius using ANSYS Fluent. The rotational speed of the fan and the velocity at fan inlet were the primary variables of the study. The variation in outlet mass flow rate and total pressure was studied for both compressible and incompressible ambient flows. Relation of mass flow rate and total pressure with inlet velocity is observed to be linear and exponential respectively. On the other hand, mass flow rate and total pressure have nearly linear relationship with rotational speed. A comparison of several different axial flow tracks with the baseline case fills one of the research gaps.

scholarly journals Cold Flow Computations for the Diffuser-Combustor Section of an Industrial Gas Turbine

1996 ◽  
Author(s):  
Dadong Zhou ◽  
Ting Wang ◽  
William R. Ryan
Keyword(s):  
Gas Turbine ◽  
Total Pressure ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Complex Flow ◽  
Pressure Losses ◽  
Structured Grid ◽  
Computational Fluid Dynamics Cfd ◽  
Enhance Efficiency ◽  
Industrial Gas Turbine

In the first part of a multipart project to analyze and optimize the complex three-dimensional diffuser-combustor section of a highly advanced industrial gas turbine under development, a computational fluid dynamics (CFD) analysts has been conducted. The commercial FEA code I-DEAS was used to complete the three-dimensional solid modeling and the structured grid generation. The flow calculation was conducted using the commercial CFD code PHOENICS. The multiblock method was employed to enhance computational capabilities. The mechanisms of the total pressure losses and possible ways to enhance efficiency by reducing the total pressure losses were examined. Mechanisms that contribute to the nonuniform velocity distribution of flow entering the combustor were also identified. The CFD results were informative and provided insight to the complex flow patterns in the reverse flow dump diffuser, however, the results are qualitative and are useful primarily as guidelines for optimization as opposed to firm design configuration selections.

Valveless-Gas-Turbine Combustors With Pressure Gain

1958 ◽  
Author(s):  
Carroll D. Porter
Keyword(s):  
Steady Flow ◽  
Gas Turbine ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Products ◽  
Efficiency Gain ◽  
Developmental Problems ◽  
Gas Turbine Combustors ◽  
Turbine Inlet ◽  
Gas Turbine Compressor

A valveless combustor has been developed which has been tested at one to three atmospheres of pressure. It discharged combustion products at practical turbine-inlet temperatures and at a total pressure above that of the inlet. Developmental problems encountered and results are discussed. The smooth combustor cycle, a phased system of combustor tubes and pulsation traps, achieves steady flow at the inlet and outlet of the combustor system to preserve the high efficiency of today’s turbines and compressors. The combustor will soon be tested on a gas-turbine compressor to verify efficiency gain estimates.

The impact of gas turbine compressor rotor bow on aircraft operations

2017 ◽  
Vol 121 (1246) ◽  
pp. 1808-1832 ◽  
Author(s):  
E.O. Smith ◽  
A.J. Neely ◽  
H. Palfrey-Sneddon
Keyword(s):  
Gas Turbine ◽  
Thermal Gradient ◽  
Aircraft Engine ◽  
Turbine Engine ◽  
Operational Capability ◽  
Compressor Rotor ◽  
Hot Air ◽  
Gas Turbine Compressor ◽  
The Impact ◽  
Do So

ABSTRACTWhen a gas turbine engine is shut down it will develop a circumferential thermal gradient vertically across the compressor due to hot air rising from the cooling metal components and pooling at the top. As the hot compressor rotor drum and casing cool and contract in the presence of this thermal gradient, they do so non-uniformly and therefore will bend slightly, in a phenomenon known as rotor bow. Starting an engine under bowed conditions can result in damage, representing a risk to both airworthiness and operational capability. This study consolidates some preliminary findings by the authors relating to the drivers for rotor bow, such as engine geometry, aircraft-engine integration and rotor temperature on shutdown. The commercial and military operational considerations associated with rotor bow are also discussed, including limitations which may result from a bowed rotor; the influence of operations including the final flight and descent profiles, taxi procedures and rapid turnaround requirements; as well as some practical solutions which may be implemented to reduce the impact of rotor bow.

Investigation of an Axial Flow Compressor With Variable Reynolds Number and Inlet Casing Geometry

1978 ◽  
Author(s):  
B. Becker ◽  
O. von Schwerdtner ◽  
J. Günther
Keyword(s):  
Reynolds Number ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Flow Distribution ◽  
Pressure Level ◽  
Symmetric Flow ◽  
Flow Compressor ◽  
Gas Turbine Compressor ◽  
Theoretical Results

In the course of developing the compressor of a 100-MW gas turbine, extensive measurements took place on a test compressor provided with the four front stages scaled down to 1:4.63. The performance investigations have been supplemented by measurements of flow distribution down- and upstream of the blading, as well as at various intermediate axial positions. The test stand, operating in a closed circuit, allowed for the variation of the Reynolds number by changing the pressure level. The geometry of the inlet casing was variable as well, thus enabling the comparison of results with axial, two- and one-sided inlet flows. In this connection, the vibrational behavior of the rotating blades, besides the aerodynamics of the compressor, have been investigated. In case of the inlet casing with a two-sided inflow, additional flow field analyses have been performed using a model without compressor blading. The theoretical results calculated under the assumption of a rotational-symmetric flow, as well as the measurements at the gas turbine compressor itself, are used for comparison. The gas turbine compressor operating with a mass flow of 483 kg/s at ISO-conditions and a pressure ratio of 10 is running in the highest performance range of single-shaft compressors in operation today.

Aerodynamic Optimization of the Radial Inflow Turbine for a 100kW-Class Micro Gas Turbine Based on Metamodel-Semi-Assisted Method

2013 ◽  
Author(s):  
Shuai Shao ◽  
Qinghua Deng ◽  
Zhenping Feng
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Total Pressure ◽  
Objective Functions ◽  
Aerodynamic Optimization ◽  
Micro Gas Turbine ◽  
Static Efficiency ◽  
Radial Inflow Turbine

In this paper, an aerodynamic optimization of the radial inflow turbine for a 100kW-class micro gas turbine is conducted based on the metamodel-semi-assisted idea. The idea is applied by first using the metamodel as a rapid exploration tool and then switching to the accurate optimization without metamodel for further exploration of the design space [1]. The non-dominated sorting genetic algorithm (NSGA-II) is used to drive the optimization process and the BP neural network is used to construct the metamodel. The optimization of this radial inflow turbine is divided into two parts, the stator optimization and the rotor optimization. The stator optimization is based on the accurate optimization strategy. The minimum total pressure loss of the stator and the maximum isentropic total-to-static efficiency of the stage are considered as the objective functions with constant mass flow rate as a constraint. The rotor optimization is conducted through the metamodel-semi-assisted idea. The maximum power output and isentropic total-to-static efficiency of the stage are considered as objective functions while keeping the mass flow rate to be constant. The accurate optimization system is demonstrated to be effective for the stator optimization, and the total pressure loss is reduced by 11.6% while the mass flow rate variation is less than 1%. The rotor optimization is conducted based on the metamodel-semi-assisted optimization and the results confirm the effectiveness of this new idea. The output power of the rotor increased by 1.5%, the isentropic total-to-static efficiency of the stage increased by 1.19% and the mass flow variation is less than 1%.

scholarly journals Fitting a Pitch

2009 ◽  
Vol 131 (12) ◽  
pp. 38-42 ◽  
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Airline Industry ◽  
Axial Flow ◽  
Jet Engines ◽  
Jet Engine ◽  
Rotating Blades ◽  
Fuel Savings ◽  
Turbine Efficiency ◽  
Gas Turbine Compressor ◽  
Air Carriers

This article discusses gas turbine efficiency, which is an essential but often unappreciated aspect of turbomachine design pitch. To an engineer, the pitch of a turbo machinery blade is the angle at a representative blade cross-section between the blade chord line and the plane of the blade’s rotation. An axial flow gas turbine consists of many rows of rotating blades, interspersed with rows of stationary airfoils, called vanes or stators. The gas turbine compressor (whose first row of rotating blades in a jet engine may be a fan) draws in air, which after passing through a combustor to add energy to the air flow, powers the turbine which drives the compressor. Most modern commercial jet engines are turbofan, with a front mounted fan, whose size is indicated by the bypass ratio. During the 1990s, jet engine companies developed and tested variable pitch turbofans, with cycle studies showing between 6 and 14% fuel savings. If fuel savings could spread through the airline industry, changing the pitch could lead to air carriers singing a happier tune.

scholarly journals Gas turbine outlets: test results

2020 ◽  
Vol 4 (394) ◽  
pp. 121-128
Author(s):  
Nikolay N. Ponomarev
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Mutual Influence ◽  
Engineering Calculation ◽  
Total Pressure Loss ◽  
Flow Section ◽  
Pressure Losses ◽  
Flow Parameters

Object and purpose of research. The object of this work is gas turbine outlet consisting of axial-radial diffuser with the struts and the volute. The purpose is to create a methodology for engineering calculations, taking into account the mutual influence of the diffuser and the volute. Materials and methods. Experimental study of the flow in the models of outlets by measuring total and static pressure in characteristic sections. Calculation of integral and averaged flow parameters in measurement sections. Visualization of boundary flows. Based on the experimental results, development of regression models for the correction factors to be applied in the theoretical model, with selection of relevant factors. Main results. An experimental study of 23 variants of models with a total volume of 112 experimental points (modes) was carried out. On the basis of the experiment, methodology and program for engineering calculation of total pressure losses in the outlets were developed. It was found that the installation of guide blades and radial ribs in the diffuser in order to reduce local expansion angles with the ultimate purpose of mitigating total pressure losses actually does not lead to this result due to the because the flow in the diffuser becomes asymmetric due to its interaction with the volute. Visualization of boundary flows in the diffusers and the volutes has been performed, which makes it possible to identify the locations of separations causing increased pressure losses. Conclusion. An engineering method for calculating the total pressure loss in gas turbine outlet has been developed. The technique makes it possible, taking size restrictions into account, to select the geometry of the flow section that ensures minimum total pressure loss.

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