Probabilistic Remaining Creep Life Assessment for Gas Turbine Components under Varying Operating Conditions

2002 ◽  
Author(s):  
Zhimin Liu ◽  
Vitali Volovoi ◽  
Dimitri Mavris
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Life Assessment ◽  
Creep Life ◽  
Creep Life Assessment

Application of Surrogate Models and Probabilistic Design Methodology to Assess Creep Growth Limit of an Uncooled Turbine Blade

2018 ◽  
Author(s):  
Armin Hadadian ◽  
Sairam Prabhakar ◽  
Bjorn Sjodin ◽  
Keith Taylor
Keyword(s):  
Turbine Blade ◽  
Model Development ◽  
Engine Performance ◽  
Operating Conditions ◽  
Life Assessment ◽  
Creep Life ◽  
Validation Data ◽  
Data Set ◽  
Creep Life Assessment ◽  
The Impact

Predictive lifing with probabilistic treatment of key variables represents a promising approach to realizing the digital gas turbine of the future. In this paper, we present a predictive model for creep life assessment of an uncooled turbine blade. The model development methodology draws on well-established machine learning principles to develop and validate a surrogate model for creep life from engine performance parameters. Verified creep life results, obtained from 3D non-linear thermo-mechanical finite element simulation for varying engine operating conditions are used as the basis for model development. The selection of model response surface order is studied over a range of models by evaluating normalized residual error on training and uncorrelated validation data sets. A model that is fully quadratic in the data set features is shown to have excellent predictive capability, yielding nominal creep life predictions to within ± 3% on the validation data set. This work then considers probabilistic techniques to evaluate the impact of uncertainty associated with each key factor on the predicted nominal creep life in order to achieve a mandated life target with a defined probability of failure.

The Influence of Humidity on the Creep Life of a High Pressure Gas Turbine Blade: Part II—Case Study

2012 ◽  
Author(s):  
S. Eshati ◽  
P. Laskaridis ◽  
A. Haslam ◽  
P. Pilidis
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Life Assessment ◽  
Coolant Temperature ◽  
Creep Life

The determination of the rate of heat transfer from the turbine blade in a cross flow is important in hot section gas turbine life assessment. For design purposes, the rate of heat transfer is normally fixed by semi-empirical correlations. These correlations require knowledge of fluid properties which depend on temperature. For gases these properties are normally available only for the dry state, thus the possible effect of the water vapour content has been overlooked. Many gas turbines operate in environments in which air humidity is very low and therefore has little influence on gas turbine performance. However humidity becomes more important in hot, humid climates where there are large variations in ambient absolute humidity, especially in hot and humid climates. The aim of this paper is to investigate and present the effect of humidity at different operating conditions on the turbine blade coolant heat transfer and blade creep life. The effect of humidity was considered only on the air coolant side. he The heat transfer coefficient on the hot side was calculated for dry hot gas. This avoided the balancing effect of each other (heat transfer coefficient coolant side and hot side). The WAR at each operating point is quantified based on the ambient temperature and the relative humidity (0%–100%). Results showed that with increasing WAR the blade inlet coolant temperature reduced along the blade span. The blade metal temperature at each section was reduced as WAR increased, which in turn increased the blade creep life. The increase in WAR increased the specific heat of the coolant and increased the heat transfer capacity of the coolant air flow. Different operating points were also evaluated at different WAR and Tamb to identify the effect of WAR on the creep life. The results showed that an increase in WAR increased the blade creep life. The creep life of the blade at each section of interest was obtained as a function of the blade section stress and the blade metal section temperature using the LMP approach.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

AbstractTemperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

Abstract Temperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Creep life assessment of distribution transformers

2010 ◽  
Vol 17 (5) ◽  
pp. 1077-1085 ◽  
Author(s):  
N.S. Beniwal ◽  
D.K. Dwivedi ◽  
H.O. Gupta
Keyword(s):  
Life Assessment ◽  
Creep Life ◽  
Distribution Transformers ◽  
Creep Life Assessment

Marine Gas Turbine Performance Model for More Electric Ships

2011 ◽  
Author(s):  
George M. Koutsothanasis ◽  
Anestis I. Kalfas ◽  
Georgios Doulgeris
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Operating Conditions ◽  
Prime Mover ◽  
Creep Life ◽  
Hull Fouling ◽  
Turbine Performance

This paper presents the benefits of the more electric vessels powered by hybrid engines and investigates the suitability of a particular prime-mover for a specific ship type using a simulation environment which can approach the actual operating conditions. The performance of a mega yacht (70m), powered by two 4.5MW recuperated gas turbines is examined in different voyage scenarios. The analysis is accomplished for a variety of weather and hull fouling conditions using a marine gas turbine performance software which is constituted by six modules based on analytical methods. In the present study, the marine simulation model is used to predict the fuel consumption and emission levels for various conditions of sea state, ambient and sea temperatures and hull fouling profiles. In addition, using the aforementioned parameters, the variation of engine and propeller efficiency can be estimated. Finally, the software is coupled to a creep life prediction tool, able to calculate the consumption of creep life of the high pressure turbine blading for the predefined missions. The results of the performance analysis show that a mega yacht powered by gas turbines can have comparable fuel consumption with the same vessel powered by high speed Diesel engines in the range of 10MW. In such Integrated Full Electric Propulsion (IFEP) environment the gas turbine provides a comprehensive candidate as a prime mover, mainly due to its compactness being highly valued in such application and its eco-friendly operation. The simulation of different voyage cases shows that cleaning the hull of the vessel, the fuel consumption reduces up to 16%. The benefit of the clean hull becomes even greater when adverse weather condition is considered. Additionally, the specific mega yacht when powered by two 4.2MW Diesel engines has a cruising speed of 15 knots with an average fuel consumption of 10.5 [tonne/day]. The same ship powered by two 4.5MW gas turbines has a cruising speed of 22 knots which means that a journey can be completed 31.8% faster, which reduces impressively the total steaming time. However the gas turbine powered yacht consumes 9 [tonne/day] more fuel. Considering the above, Gas Turbine looks to be the only solution which fulfills the next generation sophisticated high powered ship engine requirements.

scholarly journals Influence of thermal-varying material properties on stress calculation for creep life assessment of seamless medium-carbon steel boiler tubes

2020 ◽  
Vol 844 ◽  
pp. 012029
Author(s):  
L M Castellanos-González ◽  
H Hernández Herrera ◽  
R Goytisolo Espinosa ◽  
L M Castellanos Molina ◽  
E E Vergara Verbel ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Material Properties ◽  
Medium Carbon Steel ◽  
Life Assessment ◽  
Creep Life ◽  
Medium Carbon ◽  
Stress Calculation ◽  
Boiler Tubes ◽  
Creep Life Assessment ◽  
Steel Boiler
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