Experimental Analyses of a Static to Static Flex Seal and a Honeycomb Seal

2016 ◽  
Author(s):  
Thomas Zierer ◽  
Cyrille Bricaud ◽  
Marcos Escudero-Olano ◽  
Joshua McNally ◽  
Afzal Pasha Mohammed
Keyword(s):  
Engine Performance ◽  
Performance Tests ◽  
Low Leakage ◽  
Turbine Performance ◽  
Honeycomb Seal ◽  
Higher Temperature ◽  
Honeycomb Seals ◽  
Secondary Air ◽  
Component Interface ◽  
Wide Usage

Improvements in turbine performance are increasingly driven by the need to control leakage both in the main gas path as well as in the secondary air flow system. Seals for static to static interfaces have a wide usage in gas turbine for component interface locations and are becoming more important as engines reach higher temperature targets and compressor pressure ratios. Both flex and honeycomb seals have been used for many years during other OEM seal service upgrades. These seals are designed to be capable of sustaining low leakage operation whilst achieving long lifetimes. To determine the sealing capability of honeycomb and flex seals an advanced hydraulically actuated rig was designed and constructed. A series of leakage performance tests were carried out that accurately simulate engine conditions, including pressure and relative axial and radial movements. The results of these tests are compared against previously presented data on standard membrane seals. Compared to the membrane seal, the flex seal has approximately 60% lower equivalent clearance when tested with uneven (triangular) grooves. This reduction was due to the bending of the seal and subsequent closing of the seal gap under pressure. The flex and membrane seal performed similarly well under more nominal conditions. The honeycomb seal achieved a consistently low leakage under all pressure loadings. All three sealing types have their place in the required technology mix which is essential when aiming for maximized engine performance and lifetime.

Numerical and Experimental Investigation of Secondary Flows and Influence of Air System Design on Heavy-Duty Gas Turbine Performance

2012 ◽  
Author(s):  
Luca Bozzi ◽  
Enrico D’angelo
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Combined Cycle ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Turbine Performance ◽  
Air System ◽  
Secondary Air

High turn-down operating of heavy-duty gas turbines in modern Combined Cycle Plants requires a highly efficient secondary air system to ensure the proper supply of cooling and sealing air. Thus, accurate performance prediction of secondary flows in the complete range of operating conditions is crucial. The paper gives an overview of the secondary air system of Ansaldo F-class AEx4.3A gas turbines. Focus of the work is a procedure to calculate the cooling flows, which allows investigating both the interaction between cooled rows and additional secondary flows (sealing and leakage air) and the influence on gas turbine performance. The procedure is based on a fluid-network solver modelling the engine secondary air system. Parametric curves implemented into the network model give the consumption of cooling air of blades and vanes. Performances of blade cooling systems based on different cooling technology are presented. Variations of secondary air flows in function of load and/or ambient conditions are discussed and justified. The effect of secondary air reduction is investigated in details showing the relationship between the position, along the gas path, of the upgrade and the increasing of engine performance. In particular, a section of the paper describes the application of a consistent and straightforward technique, based on an exergy analysis, to estimate the effect of major modifications to the air system on overall engine performance. A set of models for the different factors of cooling loss is presented and sample calculations are used to illustrate the splitting and magnitude of losses. Field data, referred to AE64.3A gas turbine, are used to calibrate the correlation method and to enhance the structure of the lumped-parameters network models.

scholarly journals The Influence of the Axial Rub Added in the Radial Rub on the Wear of the Seal Fins during the High Speed Rub of Labyrinth-Honeycomb Seal

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1997
Author(s):  
Bin Lu ◽  
Haijun Xuan ◽  
Xiaojian Ma ◽  
Fangjun Han ◽  
Weirong Hong ◽  
...  
Keyword(s):  
Wear Rate ◽  
High Speed ◽  
State Of The Art ◽  
Negative Influence ◽  
Axial Thrust ◽  
Cross Sectional ◽  
Honeycomb Seal ◽  
Aero Engine ◽  
Honeycomb Seals ◽  
Clearance Change

Labyrinth-honeycomb seals are a state-of-the-art sealing technology commonly used in aero-engine interstage seal. The undesirable severe rub between the seal fins and the honeycomb due to the clearance change may induce the cracking of the seal fins. A pervious study investigated the wear of the seal fins at different radial incursion rates. However, due to the axial thrust and mounting clearance, the axial rub between the seal fins and the honeycomb may occur. Hence, this paper focuses on the influence of the axial rub added in the radial rub on the wear of the seal fins. The rub tests results, including rubbing forces and temperature, wear rate, worn morphology, cross-sectional morphology and energy dispersive spectroscopy results, are presented and discussed. Overall, the participation of the axial rub leads to higher rubbing forces, temperature, and wear rate. The tribo-layer on the seal fin is thicker and the cracks are more obvious at high axial incursion rate. These phenomena indicate the axial rub has a negative influence on the wear of the seal fins and should be avoided.

Training Future Gas Turbine Performance Engineers

2007 ◽  
Author(s):  
V. Pachidis ◽  
P. Pilidis ◽  
I. Li
Keyword(s):  
Gas Turbine ◽  
Thermal Power ◽  
Engine Performance ◽  
Gas Turbine Engine ◽  
Performance Simulation ◽  
Turbine Engine ◽  
Turbine Performance ◽  
Auxiliary Power ◽  
Engine Testing ◽  
The Uk

The performance analysis of modern gas turbine engine systems has led industry to the development of sophisticated gas turbine performance simulation tools and the utilization of skilled operators who must possess the ability to balance environmental, performance and economic requirements. Academic institutions, in their training of potential gas turbine performance engineers have to be able to meet these new challenges, at least at a postgraduate level. This paper describes in detail the “Gas Turbine Performance Simulation” module of the “Thermal Power” MSc course at Cranfield University in the UK, and particularly its practical content. This covers a laboratory test of a small Auxiliary Power Unit (APU) gas turbine engine, the simulation of the ‘clean’ engine performance using a sophisticated gas turbine performance simulation tool, as well as the simulation of the degraded performance of the engine. Through this exercise students are expected to gain a basic understanding of compressor and turbine operation, gain experience in gas turbine engine testing and test data collection and assessment, develop a clear, analytical approach to gas turbine performance simulation issues, improve their technical communication skills and finally gain experience in writing a proper technical report.

scholarly journals Annular Honeycomb Seals: Test Results for Leakage and Rotordynamic Coefficients; Comparisons to Labyrinth and Smooth Configurations

1989 ◽  
Vol 111 (2) ◽  
pp. 293-300 ◽  
Author(s):  
D. Childs ◽  
D. Elrod ◽  
K. Hale
Keyword(s):  
Labyrinth Seal ◽  
Test Results ◽  
Rotordynamic Coefficients ◽  
Damping Coefficients ◽  
Stiffness Coefficients ◽  
Shaft Rotation ◽  
Honeycomb Seal ◽  
Cell Dimensions ◽  
Honeycomb Seals ◽  
Rotordynamic Coefficient

Test results are presented for leakage and rotordynamic coefficients for seven honeycomb seals. All seals have the same radius, length, and clearance; however, the cell depths and diameters are varied. Rotordynamic data, which are presented, consist of the direct and cross-coupled stiffness coefficients and the direct damping coefficients. The rotordynamic-coefficient data show a considerable sensitivity to changes in cell dimensions; however, no clear trends are identifiable. Comparisons of test data for the honeycomb seals with labyrinth and smooth annular seals shows the honeycomb seal had the best sealing (minimum leakage) performance, followed in order by the labyrinth and smooth seals. For prerotated fluids entering the seal, in the direction of shaft rotation, the honeycomb seal has the best rotordynamic stability followed in order by the labyrinth and smooth. For no prerotation, or fluid prerotation against shaft rotation, the labyrinth seal has the best rotordynamic stability followed in order by the smooth and honeycomb seals.

An Investigation on Performance of an Asymmetric Twin-Scroll Turbine With a Small Scroll Bypass Wastegate for a Heavy-Duty Diesel Engine

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Jianjiao Jin ◽  
Jianfeng Pan ◽  
Zhigang Lu ◽  
Qingrui Wu ◽  
Lizhong Xu ◽  
...  
Keyword(s):  
Engine Performance ◽  
Performance Tests ◽  
Turbine Efficiency ◽  
Flow Parameters ◽  
Matching Process ◽  
Heavy Duty Diesel Engine ◽  
Computational Fluid Dynamics Cfd ◽  
Heavy Duty Diesel ◽  
And Performance ◽  
Prediction Efficiency

Abstract In this paper, a novel one-dimensional matching method of an asymmetric twin-scroll turbine (ATST) with a small scroll bypass wastegate is initially presented for energy improvement. The developed method presents further insights into efficiency prediction of the ATST and the small scroll exhaust bypass in the matching process of model characterization. The efficiency of the small and large scroll turbines was approximately assessed with two times flow parameters of the small and large scroll turbines, respectively, as well as according to turbine efficiency prediction curves. Subsequently, given the matching results of a 9-L engine, a targeted ATST was developed; its effectiveness was verified by computational fluid dynamics (CFD) and the performance tests of a turbine and an engine. As revealed from the results, the prediction efficiency of the ATST well complies with that of the numerical calculation and performance tests of turbines and engines. Compared with the common large scroll exhaust bypass wastegate, the small one exhibits better engine performance and can save nearly 0.5–1.5% fuel consumption at middle and high engine speeds. Moreover, the reasons of which were explored for better understanding of the mechanism accordingly.

scholarly journals Turbine Rebuild Effects on Gas Turbine Performance

1992 ◽  
Author(s):  
J. D. MacLeod ◽  
B. Drbanski
Keyword(s):  
Gas Turbine ◽  
National Research Council ◽  
Engine Performance ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
New Methods ◽  
Turbine Performance ◽  
Turboprop Engine ◽  
Project Objectives ◽  
Performance Variations

The Engine Laboratory of the National Research Council of Canada (NRCC), with the assistance of Standard Aero Ltd., has established a program for the evaluation of component deterioration on gas turbine engine performance. As part of this project, a study of the effects of turbine rebuild tolerances on overall engine performance was undertaken. This study investigated the range of performance changes that might be expected for simply disassembling and reassembling the turbine module of a gas turbine engine, and how these changes would influence the results of the component fault implantation program. To evaluate the effects of rebuilding the turbine on the performance of a single spool engine, such as Allison T56 turboprop engine, a series of three rebuilds were carried out. This study was performed in a similar way to a previous NRCC study on the effects of compressor rebuilding. While the compressor rebuild study had found performance changes in the order of 1% on various engine parameters, the effects of rebuilding the turbine have proven to be even more significant. Based on the results of the turbine rebuild study, new methods to improve the assurance of the best possible tolerances during the rebuild process are currently being addressed. This paper describes the project objectives, the experimental installation, and the results of the performance evaluations. Discussed are performance variations due to turbine rebuilds on engine performance characteristics. As the performance changes were significant, a rigorous measurement uncertainty analysis is included.

Moisture Condensation Effect on Turbine Performance Tests

2004 ◽  
Author(s):  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Turbine Engines ◽  
Performance Tests ◽  
Gas Turbine Engines ◽  
Performance Parameters ◽  
Atmospheric Air ◽  
Turbine Performance ◽  
Working Medium ◽  
Component Test ◽  
Moisture Condensation ◽  
Condensation Effect

Water is always present in the atmospheric air in the form of vapour, affecting the operation of turbomachinery components in gas turbine engines. Due to water presence in the working medium, condensation may occur, which can influence the thermal performance of the component and alter the measurements taken for calculations. This can lead to erroneous evaluation of component performance parameters during development performance tests. Procedures to detect condensation and if possible to correct the measurements during engine or component test should be used to avoid such situations. A method allowing the prediction of condensation and the correction of the measurements for low speed expansion is presented. The method is implemented in turbine testing measurements where condensation occurs and the results show that condensation may be predicted and its effects corrected.

Alternative Microturbine Fuels Feasibility Study Through Thermal Stability, Material Compatibility, and Engine Testing

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Sergio Arias Quintero ◽  
Joshua Schmitt ◽  
Richard Blair ◽  
Jayanta Kapat
Keyword(s):  
Thermal Stability ◽  
Alternative Fuels ◽  
Low Cost ◽  
Chemical Properties ◽  
Engine Performance ◽  
Negative Effects ◽  
Operation Costs ◽  
Turbine Performance ◽  
Engine Testing ◽  
Physical And Chemical

Historically, gas turbine fuels have been procured based on availability and low cost criteria. However,in the past few decades, with the growing concern over the negative environmental impacts produced by emissions, alternative fuels have been developed and tested under the objective of reducing such negative effects. The physical properties and broad chemical composition of fuels, including trace elements, may result in engine performance issues found only after extensive operation. This, in turn, results in higher maintenance and operation costs. This paper studies the feasibility of several renewable fuels for microturbine application, identifying key relationships between the physical and chemical properties, thermal stability, materials compatibility, and turbine performance.

A Theoretical and Experimental Analysis of the Sealing Capability of a Membrane Seal

2014 ◽  
Author(s):  
Stacie Tibos ◽  
Randhir Aujla ◽  
Przemyslaw Pyzik ◽  
Martin Lewis ◽  
Sascha Justl
Keyword(s):  
Gas Turbines ◽  
Surface Condition ◽  
Test Results ◽  
Actuation System ◽  
Thermal Growth ◽  
Precise Adjustment ◽  
Wide Range ◽  
Performance Curves ◽  
Secondary Air ◽  
Component Interface

Improvements in turbine performance are increasingly being driven by the need to control leakage both in the main gas path as well as secondary air flow systems. Membrane seals have long been established as a method of sealing in some of the harshest of environments found in gas turbines. The membrane seal has a wide usage in gas turbines for stationary component interface sealing. The geometry is of plate construction with bulbous ends, the seals are assembled vertically and are retained by the component grooves. The grooves allow relative sliding and rotation against their surfaces a necessary feature, since during operation the seal needs to withstand relative movements due to thermal growth, vibratory forces, excitation and assembly loads. However, more accurate leakage estimates are required. Thus, in order to evaluate the complete performance characteristics of the seal for a wide range of working conditions, a theoretical and experimental campaign was undertaken. The membrane seal performance curves were created based on a series of tests performed in a specially designed rig. The rig utilised an actuation system that allowed for the precise adjustment of the seal’s relative position in two directions while performing the tests at a given working condition. It was noted that not only the movement and deformation of the membrane but also, assembly clearances and surface condition of the components have an impact on the seal’s performance. To assist in the understanding of the influence of the changing parameters on the performance of the seal an FEA study was undertaken employing known data to aid the understanding and improve the knowledge of how the seal behaves under specific engine conditions. The evaluation gives confidence in the experimental test results.

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