This paper summarizes a rational approach to minimizing degradation. It involves three elements. The first is quantifying and trending the degradation of the components that make up the gas turbine. The second is determining how much this degradation is impairing heat rate and capacity. The third, and perhaps most important, is to identify the physical changes in the gas turbine hardware that a...

The present study is concerned with the effect of exciting boundary layer on cooling process in a gas-turbine blades. The cooling process is numerically investigated. Observations show cooling the first row of moving or stable blades leads to increase their life-time. Results show that minimum temperature in cooling line with exciting boundary layer is lower than without exciting. Using block i...

This paper describes the design concepts and object-oriented architecture of Onyx, an extensible domain framework for computational simulation of gas turbine engines. Onyx provides a flexible environment for defining, modifying and simulating the component-based gas turbine models described in Part I of this paper. Using advanced object-oriented technologies such as design patterns and framewor...

In this paper we describe ongoing research in the areas of maintenance and warranty decision-making for gas turbines used in power plants. We first frame the problem within a larger context of equipment monitoring, diagnostics and maintenance. We then focus on describing and modeling economic issues related to warranty maintenance service from the perspectives of both the consumer (power plant ...

Supervision of performance in gas turbine applications is important in order to achieve: (i) reliable operations, (ii) low heat stress in components, (iii) low fuel consumption, and (iv) efficient overhaul and maintenance. To obtain good diagnosis performance it is important to have tests which are based on models with high accuracy. A main contribution of the thesis is a systematic design proc...

Several fundamental concepts with respect to the second-law analysis (SLA) of the turbulent flows in gas turbines are discussed in this study. Entropy and exergy equations for compressible/incompressible flows in a rotating/non-rotating frame have been derived. The exergy transformation efficiency of a gas turbine as well as the exergy transformation number for a single process step have been p...

Many studies have demonstrated the benefits of wave rotor application in gas turbine engines. The general performance trends have been generated; however, there is a question of where the most appropriate design space is. The aim of this investigation is to answer this question by showing the generalized performance trends of several four-port wave rotortopping configurations in a multi-dimensi...

A combustion instability in a combustor terminated by a nozzle is analysed and modelled based on a low order Helmholtz solver. A Large Eddy Simulation (LES) of the corresponding turbulent, compressible and reacting flow is first performed and analysed based on Dynamic Mode Decomposition (DMD). The mode with the highest amplitude shares the same frequency of oscillation as the experiment (approx...

OBJECTIVE Tuberculosis transmission in healthcare facilities contributes significantly to the TB epidemic, particularly in high HIV settings. Although improving ventilation may reduce transmission, there is a lack of evidence to support low-cost practical interventions. We assessed the efficacy of wind-driven roof turbines to achieve recommended ventilation rates, compared to current recommende...

An ensemble of case-based reasoning systems was created to diagnose unplanned shutdowns of large gas turbines. One case-based reasoning system was created for each of the four most common causes of the shutdowns. Each of these reasoners determines its confidence that the root cause it diagnoses is the actual root cause or not. A fusion module combines these confidence values into a single diagn...