Enhanced TF40B Gas Turbine Engine Design Changes to Improve Resistance to the Landing Craft Air Cushion (LCAC) Operational Environment

2003 ◽  
Author(s):  
Roger Yee ◽  
Lee Myers
Keyword(s):  
Gas Turbine ◽  
Material Selection ◽  
Guide Vane ◽  
The United States ◽  
Life Extension ◽  
Operational Environment ◽  
Guide Vanes ◽  
Service Life Extension ◽  
Air Cushion ◽  
Proper Material

The United States Navy Landing Craft Air Cushion (LCAC) vehicles, under the Service Life Extension Program (SLEP), use the Enhanced TF40B (ETF40B) gas turbine engines for main propulsion and lift. These engines provide the additional engine horsepower needed under high ambient temperature conditions, have an increase in operation reliability, and use modern digital engine control equipment. During craft operations, ETF40B engines are exposed to harsh saltwater and sand environments that will cause severe engine corrosion problems if corrosion resistant design features are not utilized. Proper material selection and utilization of anti-corrosion coatings are extremely important to ensure reliability of ETF40B engines on LCAC. This paper will document and outline the Navy’s efforts to improve the ETF40B engine’s resistance to the LCAC operating environment with a focus on the following components/features: • Carbon and Graphite Free Bushing and Washer Materials for Compressor Guide Vanes; • Coatings between the Compressor Casing and Compressor Guide Vane Bushings; • Use of a Silicone Rubber Abradable Material in the First 4 Stages of the Compressor; • Use of Anti-Corrosion Coatings on all Compressor Guide Vanes and Stems.

Development of the Full Authority Digital Engine Control (FADEC) System for the Enhanced TF40B Gas Turbine Engine on the U.S. Navy’s Landing Craft, Air Cushion (LCAC) Vehicles

2005 ◽  
Author(s):  
Lance Shappell ◽  
Lee Myers ◽  
Roger Yee
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Lessons Learned ◽  
Life Extension ◽  
Development Effort ◽  
Engine Control ◽  
Turbine Engine ◽  
Analog Control ◽  
Service Life Extension ◽  
Air Cushion

The Landing Craft Air Cushion (LCAC) Service Life Extension Program (SLEP) upgrades the current main propulsion engine and analog control system to the Enhanced TF40B (ETF40B) gas turbine configuration with a Full Authority Digital Engine Control (FADEC) system. The FADEC system is an integral part of the ETF40B gas turbine configuration and interfaces with the new LCAC Control and Alarm Monitoring System (CAMS). In addition to increased reliability, the FADEC requires minimal maintenance and can provide uninterrupted engine diagnostic capabilities. The development of the FADEC system has been an ongoing effort among the Navy, Textron Marine & Land Systems (LCAC builder), Vericor Power Systems (ETF40B manufacturer), and Precision Engine Controls Corporation (PECC) (FADEC manufacturer). This paper will outline the FADEC development effort and the lessons learned during the design, environmental qualification, testing and operation for the LCAC.

Material Selection Issues for a Nozzle Guide Vane Against Service-Induced Failure

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Xijia Wu ◽  
Zhong Zhang ◽  
Leiyong Jiang ◽  
Prakash Patnaik
Keyword(s):  
Gas Turbine ◽  
Material Selection ◽  
Guide Vane ◽  
Failure Process ◽  
Inelastic Strain ◽  
Grain Boundary Sliding ◽  
Deformation Mechanisms ◽  
Strain Component ◽  
Combustion Gas ◽  
Nozzle Guide

Nozzle guide vanes (NGV) of gas turbine engines are the first components to withstand the impingement of hot combustion gas and therefore often suffer thermal fatigue failures in service. A lifting analysis is performed for the NGV of a gas turbine engine using the integrated creep–fatigue theory (ICFT). With the constitutive formulation of inelastic strain in terms of mechanism-strain components such as rate-independent plasticity, dislocation glide-plus-climb, and grain boundary sliding (GBS), the dominant deformation mechanisms at the critical locations are thus identified quantitatively with the corresponding mechanism-strain component. The material selection scenarios are discussed with regards to damage accumulated during take-off and cruise. The interplay of those deformation mechanisms in the failure process is elucidated such that an “optimum” material selection solution may be achieved.

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.

U.S. Navy TF Series Engine Commonality and Reutilization Supporting Condition Based Maintenance

2010 ◽  
Author(s):  
Joseph Ranero
Keyword(s):  
Condition Based Maintenance ◽  
Life Extension ◽  
Budget Cuts ◽  
Support Costs ◽  
The Us ◽  
Service Life Extension ◽  
Air Cushion ◽  
Supporting Condition ◽  
Extension Program ◽  
Original Concept

This paper discusses the evolution of marine gas turbine (MGT) maintenance practices on the US Navy landing craft, air cushion (LCAC). This includes the progression from the philosophy of remove, replace and depot repair of engine modules, to a more condition based maintenance (CBM) practice. Included is the original concept of reusing all common TF40B parts, allowing the ETF40B to be created from a kit. The TF40B engine is being retired while the LCAC Service Life Extension Program (SLEP) is implemented. The propulsion part of the SLEP includes an ETF40B engine. Historically, the TF40B engine would be returned to a depot for repair. Supporting this in the past has relied on a costly and time consuming depot repair methodology. This paper will explore repair and overhaul approaches associated with the evolution of the US Navy’s philosophy. It will show the benefits of applying more on-condition type repairs, which will lead into a conditioned based overhaul (CBO) concept. There are discussions of the CBM concept that supports the current fleet. It delivers a large reduction in support costs and time consumption at a time of budget cuts and increased repair turn-around times from industry reductions in available parts and labor.

Material Selection Issues for a Nozzle Guide Vane Against Service Induced Failure

2016 ◽  
Author(s):  
Xijia Wu ◽  
Zhong Zhang ◽  
Leiyong Jiang ◽  
Prakash Patnaik
Keyword(s):  
Gas Turbine ◽  
Material Selection ◽  
Guide Vane ◽  
Failure Process ◽  
Inelastic Strain ◽  
Grain Boundary Sliding ◽  
Deformation Mechanisms ◽  
Strain Component ◽  
Combustion Gas ◽  
Nozzle Guide

Nozzle guide vanes (NGV) of gas turbine engines are the first components to withstand the impingement of hot combustion gas, and therefore often suffer thermal fatigue failures in service. A lifing analysis is performed for the NGV of a gas turbine engine using the integrated creep-fatigue theory (ICFT). With the constitutive formulation of inelastic strain in terms of mechanism-strain components such as rate-independent plasticity, dislocation glide-plus-climb, and grain boundary sliding, the dominant deformation mechanisms at the critical locations are thus identified quantitatively with the corresponding mechanism-strain component. The material selection scenarios are discussed with regards to damage accumulated during take-off and cruise. The interplay of those deformation mechanisms in the failure process are elucidated such that an “optimum” material selection solution may be achieved.

scholarly journals Unsteady phenomena at the combustor-turbine interface

2021 ◽  
Vol 5 ◽  
pp. 202-215
Author(s):  
Faisal Shaikh ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
High Speed ◽  
Guide Vane ◽  
Secondary Flows ◽  
Test Facility ◽  
Unsteady Heat Transfer ◽  
Guide Vanes ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

The combustor-turbine interface in a gas turbine is characterised by complex, highly unsteady flows. In a combined experimental and large eddy simulation (LES) study including realistic combustor geometry, the standard model of secondary flows in the nozzle guide vanes (NGV) is found to be oversimplified. A swirl core is created in the combustion chamber which convects into the first vane passages. Four main consequences of this are identified: variation in vane loading; unsteady heat transfer on vane surfaces; unsteadiness at the leading edge horseshoe vortex, and variation in the position of the passage vortex. These phenomena occur at relatively low frequencies, from 50–300 Hz. It seems likely that these unsteady phenomena result in non-optimal film cooling, and that by reducing unsteadiness designs with greater cooling efficiency could be achieved. Measurements were performed in a high speed test facility modelling a large industrial gas turbine with can combustors, including nozzle guide vanes and combustion chambers. Vane surfaces and endwalls of a nozzle guide vane were instrumented with 384 high speed thin film heat flux gauges, to measure unsteady heat transfer. The high resolution of measurements was such to allow direct visualisation in time of large scale turbulent structures over the endwalls and vane surfaces. A matching LES simulation was carried out in a domain matching experimental conditions including upstream swirl generators and transition duct. Data reduction allowed time-varying LES data to be recorded for several cycles of the unsteady phenomena observed. The combination of LES and experimental data allows physical explanation and visualisation of flow events.

Concrete Bridge Service Life Extension Using Sealers in Chloride-Laden Environments

1996 ◽  
Vol 1561 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jerzy Żemajtis ◽  
Richard E. Weyers
Keyword(s):  
United States ◽  
Service Life ◽  
The United States ◽  
Life Extension ◽  
Concrete Bridge ◽  
Public Funds ◽  
Water Based ◽  
Service Life Extension ◽  
Concrete Service ◽  
Diffusion Properties

The early deterioration of concrete structures in chloride-laden environments is well known. The severity of the deterioration of bridges in the United States has resulted in the development of a large number of corrosion protection and rehabilitation methods for service life extension. For bridge engineers to make best use of public funds, service life, service life extension, and method application costs are needed. A methodology based on diffusion properties is presented for determining the service life (reapplication period) and service life extension of concrete bridge surface treatments and sealers. Consideration is given to traffic wear, degradation by ultraviolet light, and the ability of sealers to reduce the rate of ingress of chlorides into the concrete. Service life extension periods are presented for four sealers: solvent and water-based epoxies, silane, and siloxane. Service life extension periods consider the severity of the environment and the bridge member exposure conditions.

Enhanced TF40B Gas Turbine Engine Bleed Air Anti-Ice System (BAAS) Development

2004 ◽  
Author(s):  
Roger Yee ◽  
Lee Myers
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Lessons Learned ◽  
Life Extension ◽  
Cold Weather ◽  
Development Effort ◽  
Engine Control ◽  
Turbine Engine ◽  
Service Life Extension

The Landing Craft Air Cushion (LCAC) Service Life Extension Program (SLEP) upgrades the current TF40B gas turbine engine and analog control system to an Enhanced TF40B (ETF40B) gas turbine with a Full Authority Digital Engine Control (FADEC) system. This upgrade and enhancement will provide additional engine horsepower, increased engine reliability, modern digital engine control equipment, and a Bleed Air Anti-Ice System (BAAS) for the LCAC during cold weather operations. The original permanent BAAS system for the SLEP configured LCAC has been redesigned as a “removable kit” to reduce overall craft weight and to minimize maintenance for the crews. The development has been an ongoing effort between the Navy, Textron Marine & Land Systems who is the LCAC craft builder, and Vericor Power Systems, who is the ETF40B manufacturer. This paper will document and outline the BAAS development effort and the many lessons learned during the design of a prototype BAAS system for the ETF40B engine.

Enhanced TF40B Gas Turbine Engine Development Program

2002 ◽  
Author(s):  
Roger Yee ◽  
Lee Myers ◽  
Ken Braccio ◽  
Mike Dvornak
Keyword(s):  
Gas Turbine ◽  
Development Program ◽  
Gas Turbine Engine ◽  
Life Extension ◽  
Engine Control ◽  
Turbine Engine ◽  
Analog Control ◽  
Service Life Extension ◽  
Land Systems ◽  
Engine Development

The Navy Landing Craft Air Cushion (LCAC) Service Life Extension Program (SLEP) upgrades the current TF40B gas turbine engine and analog control system on the LCAC to an Enhanced TF40B (ETF40B) gas turbine with a Full Authority Digital Engine Control (FADEC) system. This upgrade and enhancement will provide additional engine horsepower, increased engine reliability, and modern digital engine control equipment to the LCAC. The success of the ETF40B engine development program has been an ongoing effort between the Navy, the LCAC craft builder Textron Marine & Land Systems (TM&LS), and the engine manufacturer Honeywell Engine and Systems. This paper will document and outline the differences between the TF40B and ETF40B and the efforts of the ETF40B 150 hour endurance qualification test.

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