A Field Method of Determining Gas Turbine Meter Performance

1970 ◽  
Vol 92 (4) ◽  
pp. 724-731 ◽  
Author(s):  
W. F. Z. Lee ◽  
H. J. Evans
Keyword(s):  
Gas Turbine ◽  
Field Method ◽  
Experimental Results ◽  
Inexpensive Method ◽  
Analytical Results ◽  
The Relationship ◽  
Good Agreement

The need for a simple and inexpensive method for field checking gas turbine meters exists. One such method called the “spin test” is described in this paper. The relationship between the change of “rotor coast time” of the spin test and the change of meter accuracy due to change of mechanical friction is formulated. Experimental results on two different 6-in. gas turbine meters are presented and show good agreement with analytical results.

scholarly journals Modeling of microwave applicators with an excitation through the wave guide using TLM method

2005 ◽  
Vol 2 (2) ◽  
pp. 137-146
Author(s):  
Tijana Randjelovic ◽  
Jugoslav Jokovic ◽  
Bratislav Milovanovic
Keyword(s):  
Experimental Results ◽  
Wave Guide ◽  
Analytical Results ◽  
Resonant Modes ◽  
Impulse Excitation ◽  
Wave Guides ◽  
Tlm Method ◽  
Microwave Applicator ◽  
Good Agreement ◽  
Microwave Applicators

In this paper, a real microwave applicator with a wave guide used to launch the energy from the source into the cavity is analyzed using 3D TLM method. In order to investigate the influence of the positions and number of feed wave guides to the number of the resonant modes inside the cavity, obtained results are compared with analytical results and results obtained by using TLM software with an impulse excitation as well. TLM method is applied to the both empty and loaded rectangular metallic cavity, and a very good agreement between simulated and experimental results is achieved.

Unconventional Tee Forming on Metal Tubes

1985 ◽  
Vol 107 (4) ◽  
pp. 392-396 ◽  
Author(s):  
L. A. Moreira Filho ◽  
H. A. Al-Qureshi
Keyword(s):  
Upper Bound ◽  
Work Hardening ◽  
Experimental Results ◽  
Empirical Expression ◽  
Forming Load ◽  
Tee Junction ◽  
The Relationship ◽  
Bound Theory ◽  
Good Agreement ◽  
Upper Bound Theory

An experimental machine using elastomer rod has been developed for the forming of tee-junction on metal tubes. This was achieved by applying loading-unloading cycles to the tube and the elastomer simultaneously. The success of the operation is governed by the so called “clearance height” which controls the relationship between the displaced volume of the elastomer and the reduced length of the tube. Present experiments have confirmed the validity of the empirical expression previously found. The upper-bound theory is found to be in good agreement with experimental results, for predicting the total forming load. The experiments were performed on materials with different work-hardening characteristics. In addition, the effects of other variables on the process are examined.

scholarly journals Sperm numbers and fertility: a kinetic approach.

1965 ◽  
Vol 13 (4) ◽  
pp. 378-391
Author(s):  
C. Van Duijn
Keyword(s):  
Kinetic Theory ◽  
Experimental Results ◽  
Kinetic Approach ◽  
The Relationship ◽  
Sperm Movement ◽  
Good Agreement

A kinetic theory is derived for the relationship between numbers of spermatozoa, sperm movement, and the probability of fertilization. The theory shows good agreement with experimental results. Cf. A.B.A., 33, Nos. 1872 and 1873. F. S. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Computing and Analyzing the Sensitivity of Radial-Basis Function Neural Network

2013 ◽  
Vol 321-324 ◽  
pp. 1957-1961
Author(s):  
Jie Li ◽  
Jun Li ◽  
Ying Liu
Keyword(s):  
Neural Network ◽  
Radial Basis Function ◽  
Uniform Distribution ◽  
Basis Function ◽  
Experimental Results ◽  
Radial Basis ◽  
The Relationship ◽  
Theoretical Results ◽  
Input Error ◽  
Good Agreement

This paper proposes an algorithm to compute the sensitivity of the Radial-Basis Function Neural Network (RBFNN) due to the errors of the inputs and others parameters of the net works. For simplicity and practicality, all inputs and weights are assumed to be independent and identically distributed (i.i.d) with uniform distribution. A number of simulations are conducted and the good agreement between the experimental results and the theoretical results verifies the reliability and feasibility of the proposed algorithm. The relationship between the sensitivity of RBFNN and input error and the perturbation of others parameters is given.

scholarly journals Laser Thermochemical High-Contrast Recording on Thin Metal Films

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Elena A. Shakhno ◽  
Quang D. Nguyen ◽  
Dmitry A. Sinev ◽  
Elizaveta V. Matvienko ◽  
Roman A. Zakoldaev ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Experimental Results ◽  
Visible Range ◽  
High Contrast ◽  
Laser Parameters ◽  
Direct Laser ◽  
Contrast Structures ◽  
Direct Laser Interference Patterning ◽  
The Relationship ◽  
Good Agreement

Laser-induced thermochemical recording of nano- and microsized structures on thin films has attracted intense interest over the last few decades due to essential applications in the photonics industry. Nevertheless, the relationship between the laser parameters and the properties of the formed oxide structures, both geometrical and optical, is still implicit. In this work, direct laser interference patterning of the titanium (Ti) film in the oxidative regime was applied to form submicron periodical structures. Depending on the number of laser pulses, the regime of high contrast structures recording was observed with the maximum achievable thickness of the oxide layer. The investigation revealed high transmittance of the formed oxide layers, i.e., the contrast of recorded structures reached up to 90% in the visible range. To analyze the experimental results obtained, a theoretical model was developed based on calculations of the oxide formation dynamics. The model operates on Wagner oxidation law and the corresponding optical properties of the oxide–metal–glass substrate system changing nonlinearly after each pulse. A good agreement of the experimental results with the modeling estimations allowed us to extend the model application to other metals, specifically to those with optically transparent oxides, such as zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), and tantalum (Ta). The performed analysis highlighted the importance of choosing the correct laser parameters due to the complexity and nonlinearity of optical, thermal, and chemical processes in the metal film during its laser-induced oxidation in the air. The developed model allowed selecting the suitable temporal–energetic regimes and predicting the optical characteristics of the structures formed with an accuracy of 10%. The results are promising in terms of their implementation in the photonics industry for the production of optical converters.

Modelling Flame-Generated Noise in a Partially Premixed, Bluff Body Stabilized Model Combustor

2012 ◽  
Author(s):  
Saverio Tufano ◽  
Phil Stopford ◽  
J. C. Roman Casado ◽  
J. B. W. Kok
Keyword(s):  
Gas Turbine ◽  
Bluff Body ◽  
Cfd Simulation ◽  
Experimental Results ◽  
Combustion Model ◽  
Acoustic Oscillations ◽  
Gas Turbine Combustors ◽  
Resonance Frequencies ◽  
Partially Premixed ◽  
Good Agreement

Numerical simulation using Computational Fluid Dynamics (CFD) has become increasingly important as a tool to predict the potential occurrence of combustion instabilities in gas turbine combustors operating in lean premixed mode. Within the EU-funded Marie Curie project, LIMOUSINE (Limit cycles of thermo-acoustic oscillations in gas turbine combustors), a model test burner has been built in order to have reproducible experimental results for model validation. The burner consists of a Rijke tube of rectangular section having a flame-stabilizing wedge at about 1/4 of its length. Fuel and air supplies were carefully designed to give closed end acoustic inlet boundary conditions while the atmospheric outlet representing an acoustically open end. A transient CFD simulation of the turbulent, partially premixed, bluff body stabilized combusting flow has been carried out for the LIMOUSINE burner using ANSYS CFX commercial software. A 2-D section has been modelled by means of the scale resolving turbulence model, Scale-Adaptive Simulation (SAS), and a two-step Eddy Dissipation combustion model. Experiments were performed on the LIMOUSINE model burner to measure the dynamic variation of pressure and temperature. Results were obtained for several cases with power input ranging from 40 to 60 kW and air factors between 1.2 and 1.8. The CFD results are found to be in good agreement with experiments: the flame is predicted to stabilise on the bluff body in the fluid recirculation zone; resonance frequencies are found to change depending on power and air excess ratio and have a good agreement with experimental results and analytical values; pressure oscillations are consistent with pipe acoustic modes.

Airfoil Deflection Characteristics During Rub Events

2010 ◽  
Author(s):  
Kevin E. Turner ◽  
Michael Dunn ◽  
Corso Padova
Keyword(s):  
Adverse Effects ◽  
Gas Turbine ◽  
Ohio State University ◽  
Applied Force ◽  
Experimental Results ◽  
State University ◽  
The Ohio State University ◽  
Transient Forces ◽  
The Relationship ◽  
Key Parameter

The turbomachinery industry continually struggles with the adverse effects of contact rubs between airfoils and casings. The key parameter controlling the severity of a given rub event is the contact load produced when the airfoil tips incur into the casing. These highly non-linear and transient forces are difficult to calculate and their effects on the static and rotating components are not well understood. To help provide this insight, experimental and analytical capabilities have been established and exercised through an alliance between GE Aviation and The Ohio State University Gas Turbine Laboratory. One of the early findings of the program is the influence of blade flexibility on the physics of rub events. The focus of this paper is to quantify the influence of airfoil flexibility through a novel modeling approach that is based on the relationship between applied force duration and maximum tip deflection. Results from the model are compared to experimental results, providing sound verification.

scholarly journals Inexpensive and Accurate Measuring Device forWater Constitute in Oil

2006 ◽  
Vol 3 (1) ◽  
pp. 63
Author(s):  
M. Habli ◽  
M. Meribout ◽  
A. Al-Naamany ◽  
K. Al Busaidi
Keyword(s):  
High Resolution ◽  
Full Range ◽  
Experimental Results ◽  
Measuring Device ◽  
New Device ◽  
The Relationship ◽  
Very High ◽  
Good Agreement

This paper presents an inexpensive and accurate measuring device for water constitute in oil. The new device is based on the relationship between the water constitute in oil and the pressure of a sample from the oil. Experimental results show that the device can attain a very high resolution that can reach up +/- 0.4% and it can be used to measure a full range of water percentage levels (0-100%). Experimental results showed good agreement with theory. 

On the Stabilizing Methods of Externally Pressurized Thrust Gas Bearings

1967 ◽  
Vol 89 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Haruo Mori ◽  
Atsunobu Mori
Keyword(s):  
Experimental Results ◽  
Fluid Restriction ◽  
Theoretical Base ◽  
Gas Bearings ◽  
Analytical Results ◽  
Supply Line ◽  
Gas Supply ◽  
Good Agreement

Two kinds of stabilizing methods for externally pressurized thrust gas bearings are presented and analyzed. Both stabilizers of them are composed of fluid restriction and capacitance. The first type of stabilizer, which has been investigated by Loch, has a pair of restriction and capacitance attached additionally to the bearing recess, and the second type has the pair inserted into the gas-supply line to the bearing recess. Since the theoretical base of Loch’s analysis had questionable points, the analysis by the authors is started from a new and different standpoint and applied to the second type as well as to the first type. Experimental results show good agreement with the analytical results and the design of the stabilizers has been established.

scholarly journals Experimental Research on Static Stiffness of the Planetary Roller Screw Mechanism

2020 ◽  
Vol 306 ◽  
pp. 02002
Author(s):  
Ma Shangjun ◽  
Wu Guanyu ◽  
Zhang Jianxin ◽  
Liu Geng
Keyword(s):  
Elastic Deformation ◽  
Experimental Results ◽  
Static Stiffness ◽  
Machining Error ◽  
Analytical Results ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Stiffness Characteristics ◽  
Assembly Error ◽  
Good Agreement

This paper investigates the static stiffness characteristics of the planetary roller screw mechanism (PRSM). Firstly, an analytical model of elastic deformation in the PRSM considering contact deformation, combined deformation of screw shaft and thread deformations is established. Then, an accuracy coefficient is introduced to take into account the effect of machining error and assembly error on elastic deformation. Secondly, the stiffness tests of the PRSM are performed under different loads and nut positions. Lastly, the correctness of the analytical results is verified via the comparison with experimental results. The results show that the analytical results are in good agreement with the experimental results, and the stiffness variations under different loads and nut positions are obtained.

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