On-Line Component Map Adaptive Procedure Based on Sensor Data

Volume 1: Aircraft Engine; Fans and Blowers ◽

10.1115/gt2020-16242 ◽

2020 ◽

Author(s):

Xuesen Yang ◽

Xiaofeng Guo ◽

Wei Dong

Keyword(s):

Finite Difference ◽

Gas Turbine ◽

Optimization Procedure ◽

Measured Data ◽

Sensor Data ◽

Mode Switching ◽

Correction Factors ◽

Adaptive Procedure ◽

Primal Dual ◽

On Line

Abstract A key challenge in the gas turbine community is to adapt the engine model by matching measured data with simulation data. This study presents a procedure aiming to calibrate a certain type of gas turbine for power generation. To reproduce degradation, disturbance is injected into the healthy components maps at different time. Subsequently, six correction factors along with measured data and unmeasured parameters are coupled together using cooperative working equations and optimized based on primal-dual interior point method. When performing the adaptive procedure, Jacobian and hessian matrices are calculated using finite difference since the component maps have external, mapped, functions implemented as lookup-tables, and mode-switching statements. To improve the accuracy of first-order and second-order partial derivatives, the finite difference is enhanced by Richardson extrapolation method. The search scope of correction factors and unmeasured parameters are determined by the whole working conditions. Meanwhile, an adaptive update method of initial solution is proposed to make sure the convergence of the optimization procedure as quickly as possible. Finally, the proposed method is further applied to the on-line adaptation in case of performance degradation. The influence of measurement noise on optimization is also studied. It is demonstrated that the procedure is capable of refining the component maps progressively, which is significant for the model-based gas path diagnostics and prognostics.

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On-Line Component Map Adaptive Procedure Based on Sensor Data

10.1115/1.0002472v ◽

2021 ◽

Author(s):

Xuesen Yang ◽

Xiaofeng Guo ◽

Wei Dong

Keyword(s):

Sensor Data ◽

Adaptive Procedure ◽

On Line ◽

Component Map

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Enhancing finite difference approximations for double barrier options: mesh optimization and repeated Richardson extrapolation

Computational Management Science ◽

10.1007/s10287-021-00394-9 ◽

2021 ◽

Author(s):

Luca Vincenzo Ballestra

Keyword(s):

Finite Difference ◽

Optimization Procedure ◽

Richardson Extrapolation ◽

Mesh Optimization ◽

Option Prices ◽

Barrier Option ◽

Double Barrier ◽

Finite Difference Approximations ◽

Barrier Option Pricing ◽

Richardson Extrapolation Technique

AbstractWe show that the performances of the finite difference method for double barrier option pricing can be strongly enhanced by applying both a repeated Richardson extrapolation technique and a mesh optimization procedure. In particular, first we construct a space mesh that is uniform and aligned with the discontinuity points of the solution being sought. This is accomplished by means of a suitable transformation of coordinates, which involves some parameters that are implicitly defined and whose existence and uniqueness is theoretically established. Then, a finite difference scheme employing repeated Richardson extrapolation in both space and time is developed. The overall approach exhibits high efficacy: barrier option prices can be computed with accuracy close to the machine precision in less than one second. The numerical simulations also reveal that the improvement over existing methods is due to the combination of the mesh optimization and the repeated Richardson extrapolation.

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DOLARS, a Distributed On-Line Activity Recognition System by Means of Heterogeneous Sensors in Real-Life Deployments—A Case Study in the Smart Lab of The University of Almería

Sensors ◽

10.3390/s21020405 ◽

2021 ◽

Vol 21 (2) ◽

pp. 405

Author(s):

Marcos Lupión ◽

Javier Medina-Quero ◽

Juan F. Sanjuan ◽

Pilar M. Ortigosa

Keyword(s):

Real Time ◽

Activity Recognition ◽

Real Life ◽

Recognition System ◽

Machine Learning Algorithms ◽

Sensor Data ◽

Heterogeneous Sensors ◽

On Line ◽

The University

Activity Recognition (AR) is an active research topic focused on detecting human actions and behaviours in smart environments. In this work, we present the on-line activity recognition platform DOLARS (Distributed On-line Activity Recognition System) where data from heterogeneous sensors are evaluated in real time, including binary, wearable and location sensors. Different descriptors and metrics from the heterogeneous sensor data are integrated in a common feature vector whose extraction is developed by a sliding window approach under real-time conditions. DOLARS provides a distributed architecture where: (i) stages for processing data in AR are deployed in distributed nodes, (ii) temporal cache modules compute metrics which aggregate sensor data for computing feature vectors in an efficient way; (iii) publish-subscribe models are integrated both to spread data from sensors and orchestrate the nodes (communication and replication) for computing AR and (iv) machine learning algorithms are used to classify and recognize the activities. A successful case study of daily activities recognition developed in the Smart Lab of The University of Almería (UAL) is presented in this paper. Results present an encouraging performance in recognition of sequences of activities and show the need for distributed architectures to achieve real time recognition.

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The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

Journal of Engineering for Power ◽

10.1115/1.3446412 ◽

1978 ◽

Vol 100 (4) ◽

pp. 640-646 ◽

Cited By ~ 2

Author(s):

P. Donovan ◽

T. Cackette

Keyword(s):

Gas Turbine ◽

Pressure Ratio ◽

Turbine Engines ◽

Inlet Temperature ◽

Gas Turbine Engines ◽

Correction Factors ◽

Oxides Of Nitrogen ◽

Ambient Conditions ◽

Nitrogen Emission ◽

Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

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On-Line Simulation of 2D Resonators with Reduced Dispersion Error using Compact Implicit Finite Difference Methods

2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07 ◽

10.1109/icassp.2007.366672 ◽

2007 ◽

Cited By ~ 2

Author(s):

Konrad Kowalczyk ◽

Maarten van Walstijn

Keyword(s):

Finite Difference ◽

Finite Difference Methods ◽

Dispersion Error ◽

On Line ◽

Implicit Finite Difference ◽

Difference Methods

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Accommodation of Multi-Shaft Gas Turbine Switching Control Gain Tuning Problem to IGV Position

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4052559 ◽

2021 ◽

Author(s):

Yujia Ma ◽

Liu Jinfu ◽

Linhai Zhu ◽

Qi Li ◽

Huanpeng Liu ◽

...

Keyword(s):

Gas Turbine ◽

Guide Vane ◽

Optimization Procedure ◽

Switching Control ◽

Inlet Guide Vane ◽

Multi Objective ◽

Control Gain ◽

Controller Gain ◽

Compressor Inlet ◽

Comprehensive Indicator

Abstract This article aims to discuss the influence of compressor Inlet Guide Vane (IGV) position on gas turbine switching control system gain tuning problem. The distinction between IGV and normally reckoned working conditions is differentiated, and an improved double-layer LPV model is proposed to estimate the protected parameters under various IGV positions. Controller gain tuning is conducted with single and multi-objective intellectual optimization algorithms. Simulation results reveal that normally used multi-objective optimization procedure is unnecessary and time-consuming. While with the comprehensive indicator introduced in this paper, the calculation burden can be greatly eased. This improvement is especially advantageous when tuning work is carried out under multiple IGV positions.

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How to Get Component Maps for Aircraft Gas Turbine Performance Calculations

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; General ◽

10.1115/96-gt-164 ◽

1996 ◽

Cited By ~ 20

Author(s):

Joachim Kurzke

Keyword(s):

Gas Turbine ◽

High Speed ◽

Measured Data ◽

Turbine Performance ◽

The Many ◽

Map Data ◽

Performance Calculation ◽

Excellent Tool ◽

Very High ◽

Drawing Program

Precise simulations of gas turbine performance cannot be done without component maps. In the early days of a new project one often has to use scaled maps of similar machines. Alternatively one can calculate the component partload characteristics provided that the many details needed for such an exercise are available. In a later stage often rig tests will be done to get detailed information about the behavior of the compressors respectively turbines. Performance calculation programs usually require the map data in a specific format. To produce this format needs some preprocessing. Measured data cannot be used directly because they show a scatter and they are not evenly distributed over the range of interest. Due to limitations in the test equipment often there is lack of data for very low and very high speed. With the help of a specialized drawing program available on a PC one can easily eliminate the scatter in the data and also inter- and extrapolate additional lines of constant corrected speed. Many graphs showing both the measured data and the lines passing through the data as a function of physically meaningful parameters allow to check whether the result makes sense or not. The extrapolation of compressor maps toward very low speed, as required for the calculation of starting, idle and windmilling performance calculations, is discussed in some detail. Instead of true measured data one can use data read from maps published in open literature. The program is also an excellent tool for checking and extending component maps one has derived from sparse information about a gas turbine to be simulated.

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Determination of Cycle Configuration of Gas Turbines and Aircraft Engines by Optimization Procedure

Volume 2: Aircraft Engine; Marine; Microturbines and Small Turbomachinery ◽

10.1115/90-gt-115 ◽

1990 ◽

Author(s):

Yoshiharu Tsujikawa ◽

Makoto Nagaoka

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Specific Impulse ◽

Optimization Procedure ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Aircraft Engines ◽

Scramjet Engine ◽

Aero Engines

This paper is devoted to the analyses and optimization of simple and sophisticated cycles, particularly for various gas turbine engines and aero-engines (including scramjet engine) to achive the maximum performance. The optimization of such criteria as thermal efficiency, specific output and total performance for gas turbine engines, and overall efficiency, non-dimensional thrust and specific impulse for aero-engines have been performed by the optimization procedure with multiplier method. The comparisons of results with analytical solutions establishes the validity of the optimization procedure.

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