Prediction of Silencer Performance Using Transmission Line Theory

1971 ◽  
Vol 93 (4) ◽  
pp. 404-410
Author(s):  
R. J. Wells ◽  
R. B. Tatge
Keyword(s):  
Gas Turbine ◽  
Transmission Lines ◽  
Low Frequency ◽  
Frequency Range ◽  
Electrical Transmission ◽  
Transmission Line Theory ◽  
One Dimensional ◽  
Line Theory ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

The size and cost of gas turbine exhaust silencers are largely set by low-frequency requirements. In that frequency range, the silencer cross-dimensions are small compared to the wavelength; it can therefore be considered to be one dimensional. Equations analogous to those governing electrical transmission lines can be written to predict the acoustical performance. Agreement between measured and predicted attenuation is good.

scholarly journals On Heaviside's contributions to transmission line theory: waves, diffusion and energy flux

2018 ◽  
Vol 376 (2134) ◽  
pp. 20170457
Author(s):  
Christopher Donaghy-Spargo
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Physical Nature ◽  
Electromagnetic Theory ◽  
Electrical Transmission ◽  
Important Work ◽  
Transmission Line Theory ◽  
Energy Current ◽  
Electrical Transmission Line ◽  
Line Theory

This paper surveys some selected contributions of Oliver Heaviside FRS (1850–1925) to classical electromagnetic theory and electrical engineering science. In particular, the paper focuses on his contributions to the development of electrical transmission line theory and his deep insights into the ‘physical’ nature of the phenomena relating to nineteenth century telegraphic problems. Following a brief historical introduction to the life of Heaviside to put his achievements in context, we explore his contributions to the reformulation of Maxwell's equations and the understanding of electromagnetic wave propagation along the external region of transmission lines. This leads naturally to his researches regarding the electromagnetic diffusion process inside the line conductors and his subsequent realization that the circuital parameters, usually assumed constant, are not always so. Finally, taking both these internal and external viewpoints of the conductors, his important work regarding the flow of energy described by his ‘energy current’ concept is presented. This article is part of the theme issue ‘Celebrating 125 years of Oliver Heaviside's ‘Electromagnetic Theory’’.

Acoustic Characteristics of a Gas Turbine Exhaust Model

1974 ◽  
Vol 96 (3) ◽  
pp. 181-184 ◽  
Author(s):  
J. R. Cummins
Keyword(s):  
Gas Turbine ◽  
Acoustic Radiation ◽  
Flow Path ◽  
Scale Model ◽  
Temperature Ratio ◽  
Acoustic Characteristics ◽  
Gas Turbine Exhaust ◽  
Acoustical Data ◽  
Turbine Exhaust

To investigate the sources of acoustic radiation from a gas turbine exhaust, a one-seventh scale model has been constructed. The model geometrically scales the flow path downstream of the rotating parts including support struts and turning vanes. A discussion and comparison of different kinds of aerodynamic and acoustic scaling techniques are given. The effect of the temperature ratio between model and prototype is found to be an important parameter in comparing acoustical data.

Prediction of Pressure Rise in a Gas Turbine Exhaust Duct Under Flameout Scenarios While Operating On Hydrogen and Natural Gas Blends

2021 ◽  
Author(s):  
Orlando Ugarte ◽  
Suresh Menon ◽  
Wayne Rattigan ◽  
Paul Winstanley ◽  
Priyank Saxena ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Model ◽  
Computational Domain ◽  
Cfd Model ◽  
Exhaust Duct ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Abstract In recent years, there is a growing interest in blending hydrogen with natural gas fuels to produce low carbon electricity. It is important to evaluate the safety of gas turbine packages under these conditions, such as late-light off and flameout scenarios. However, the assessment of the safety risks by performing experiments in full-scale exhaust ducts is a very expensive and, potentially, risky endeavor. Computational simulations using a high fidelity CFD model provide a cost-effective way of assessing the safety risk. In this study, a computational model is implemented to perform three dimensional, compressible and unsteady simulations of reacting flows in a gas turbine exhaust duct. Computational results were validated against data obtained at the simulated conditions in a representative geometry. Due to the enormous size of the geometry, special attention was given to the discretization of the computational domain and the combustion model. Results show that CFD model predicts main features of the pressure rise driven by the combustion process. The peak pressures obtained computationally and experimentally differed in 20%. This difference increased up to 45% by reducing the preheated inflow conditions. The effects of rig geometry and flow conditions on the accuracy of the CFD model are discussed.

scholarly journals General Design Considerations for Gas Turbine Waste Heat Steam Generators

1968 ◽  
Author(s):  
W. V. Hambleton
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Steam Generation ◽  
Steam Generators ◽  
Design Considerations ◽  
Exhaust Heat ◽  
Gas Turbine Exhaust ◽  
Exhaust Heat Recovery ◽  
Turbine Exhaust

This paper represents a study of the overall problems encountered in large gas turbine exhaust heat recovery systems. A number of specific installations are described, including systems recovering heat in other than the conventional form of steam generation.

A Fluidic Technique for Measuring the Average Temperature in a Gas Turbine Exhaust Duct

1968 ◽  
Vol 90 (3) ◽  
pp. 265-270 ◽  
Author(s):  
C. G. Ringwall ◽  
L. R. Kelley
Keyword(s):  
Gas Turbine ◽  
Wave Velocity ◽  
Test Data ◽  
Output Pressure ◽  
Average Temperature ◽  
Phase Discrimination ◽  
Exhaust Duct ◽  
Average Wave ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Circuit concepts and test data for a fluidic system to sense the average temperature in a gas turbine exhaust duct are presented. Phase discrimination techniques are used to sense the average wave velocity in a long tube and to produce an output pressure differential proportional to temperature error.

scholarly journals A Different Approach to Gas Turbine Exhaust Silencing

1974 ◽  
Author(s):  
Marv Weiss
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Unique Method ◽  
Acoustic Testing ◽  
Gas Turbine Exhaust ◽  
Attenuation Values ◽  
Turbine Exhaust

A unique method for silencing heavy-duty gas turbines is described. The Switchback exhaust silencer which utilizes no conventional parallel baffles has at operating conditions measured attenuation values from 20 dB at 63 Hz to 45 dB at higher frequencies. Acoustic testing and analyses at both ambient and operating conditions are discussed.

scholarly journals High-Temperature Profile Monitoring in Gas Turbine Exhaust-Gas Diffusors with Six-Point Fiber-Optic Sensor Array

2020 ◽  
Vol 5 (4) ◽  
pp. 25
Author(s):  
Franz J. Dutz ◽  
Sven Boje ◽  
Ulrich Orth ◽  
Alexander W. Koch ◽  
Johannes Roths
Keyword(s):  
Gas Turbine ◽  
Fiber Optic ◽  
Characteristic Temperature ◽  
Fiber Optic Sensor ◽  
Exhaust Gas ◽  
Radial Temperature ◽  
Temperature Probe ◽  
Steel Protection ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

In this paper, the deployment of a newly developed, multipoint, fiber-optic temperature-sensor system for temperature distribution measurements in a 6 MW gas turbine is demonstrated. The optical sensor fiber was integrated in a stainless steel protection cable with a 1.6 mm outside diameter. It included six measurement points, distributed over a length of 110 mm. The sensor cable was mounted in a temperature probe and was positioned radially in the exhaust-gas diffusor of the turbine. With this temperature probe, the radial temperature profiles in the exhaust-gas diffusor were measured with high spatial and temporal resolution. During a test run of the turbine, characteristic temperature gradients were observed when the machine operated at different loads.

scholarly journals A Fault Diagnosis Approach for Gas Turbine Exhaust Gas Temperature Based on Fuzzy C-Means Clustering and Support Vector Machine

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhi-tao Wang ◽  
Ning-bo Zhao ◽  
Wei-ying Wang ◽  
Rui Tang ◽  
Shu-ying Li
Keyword(s):  
Fault Diagnosis ◽  
Gas Turbine ◽  
Clustering Algorithm ◽  
Support Vector ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Fcm Clustering ◽  
Gas Turbine Exhaust ◽  
Exhaust Gas Temperature ◽  
Turbine Exhaust

As an important gas path performance parameter of gas turbine, exhaust gas temperature (EGT) can represent the thermal health condition of gas turbine. In order to monitor and diagnose the EGT effectively, a fusion approach based on fuzzy C-means (FCM) clustering algorithm and support vector machine (SVM) classification model is proposed in this paper. Considering the distribution characteristics of gas turbine EGT, FCM clustering algorithm is used to realize clustering analysis and obtain the state pattern, on the basis of which the preclassification of EGT is completed. Then, SVM multiclassification model is designed to carry out the state pattern recognition and fault diagnosis. As an example, the historical monitoring data of EGT from an industrial gas turbine is analyzed and used to verify the performance of the fusion fault diagnosis approach presented in this paper. The results show that this approach can make full use of the unsupervised feature extraction ability of FCM clustering algorithm and the sample classification generalization properties of SVM multiclassification model, which offers an effective way to realize the online condition recognition and fault diagnosis of gas turbine EGT.

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