scholarly journals Application of Advanced Diagnostics to Airblast Injector Flows

1989 ◽  
Vol 111 (1) ◽  
pp. 53-62 ◽  
Author(s):  
J. B. McVey ◽  
J. B. Kennedy ◽  
S. Russell
Keyword(s):  
Flux Distribution ◽  
Liquid Droplet ◽  
Laser Doppler Velocimeter ◽  
Fuel Injector ◽  
Two Phase ◽  
Turbine Engine ◽  
Design Procedures ◽  
Phase Doppler Anemometer ◽  
Injector Flows ◽  
Component Phase

Experimental data on the characteristics of the spray produced by a gas turbine engine airblast fuel injector are reported. The data acquired include the mass-flux distribution, measured by use of a high-resolution spray patternator; the gas-phase velocity field, measured by use of a two-component laser-Doppler velocimeter; and the liquid droplet size and velocity distributions, measured by use of a single-component phase-Doppler anemometer. The data are intended for use in assessments of two-phase flow computational methods as applied to combustor design procedures.

Experimental Study of Dispersed Droplets in High-Pressure Annular Flows

1999 ◽  
Vol 121 (4) ◽  
pp. 924-933 ◽  
Author(s):  
T. A. Trabold ◽  
R. Kumar ◽  
P. F. Vassallo
Keyword(s):  
Void Fraction ◽  
High Pressures ◽  
Liquid Droplet ◽  
Droplet Velocity ◽  
Laser Doppler Velocimeter ◽  
Two Phase ◽  
R 134A ◽  
Gamma Densitometer ◽  
Density Ratios ◽  
Hot Film

Local measurements were made in a droplet-laden vapor core in upward R-134a annular flow in a high aspect ratio vertical duct. These detailed measurements are unique in that they were performed at high pressures and low liquid-to-vapor density ratios. Using a gamma densitometer, hot-film anemometer and laser Doppler velocimeter, profiles of void fraction, liquid droplet frequency, and droplet velocity were acquired across the narrow test section dimension. At relatively high flows, the measured void fraction was highest near the wall, due to the thinning of the liquid film. The dip in the void fraction in the vapor core at these flows suggests significant droplet entrainment. The entrainment fractions for these refrigerant flows fall in the range measured for pressurized steam-water systems. The average drop size, calculated from direct measurements of void fraction, droplet velocity, and frequency, compares favorably with previous experimental results from the literature. These data are useful for developing an improved understanding of practical two-phase flows, and for assessment of advanced two-fluid computer codes.

Compressor Exit Conditions and Their Impact on Flame Tube Injector Flows

1999 ◽  
Vol 124 (1) ◽  
pp. 10-19 ◽  
Author(s):  
A. G. Barker ◽  
J. F. Carrotte
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Test Facility ◽  
Fuel Injector ◽  
Turbine Engine ◽  
Flame Tube ◽  
Subsequent Effect ◽  
Injector Flows ◽  
Flow Compressor ◽  
Combustion Processes

Within a gas turbine engine the flow field issuing from the compression system is nonuniform containing, for example, circumferential and radial variations in the flow field due to wakes from the upstream compressor outlet guide vanes (OGVs). In addition, variations can arise due to the presence of radial load bearing struts within the pre-diffuser. This paper is concerned with the characterization of this nonuniform flow field, prior to the combustion system, and the subsequent effect on the flame tube fuel injector flows and hence combustion processes. A mainly experimental investigation has been undertaken using a fully annular test facility which incorporates a single stage axial flow compressor, diffuser, and flame tube. Measurements have been made of the flow field, and its frequency content, within the dump cavity. Furthermore, the stagnation pressure presented to the core, outer and dome swirler passages of a fuel injector has been obtained for different circumferential positions of the upstream OGV/pre-diffuser assembly. These pressure variations, amounting to as much as 20 percent of the pressure drop across the fuel injector, also affect the flow field immediately downstream of the injector. In addition, general variations in pressure around the fuel injector have also been observed due to, for example, the fuel injector position relative to pre-diffuser exit and the flame tube cowl.

scholarly journals Compressor Exit Conditions and Their Impact on Flame Tube Fuel Injector Flows

1999 ◽  
Author(s):  
A. G. Barker ◽  
J. F. Carrotte
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Test Facility ◽  
Fuel Injector ◽  
Turbine Engine ◽  
Flame Tube ◽  
Subsequent Effect ◽  
Injector Flows ◽  
Flow Compressor ◽  
Combustion Processes

Within a gas turbine engine the flow field issuing from the compression system is non-uniform containing, for example, circumferential and radial variations in the flow field due to wakes from the upstream compressor outlet guide vanes (OGVs). In addition, variations can arise due to the presence of radial load bearing struts within the pre-diffuser. This paper is concerned with the characterisation of this non-uniform flow field, prior to the combustion system, and the subsequent effect on the flame tube fuel injector flows and hence combustion processes. A mainly experimental investigation has been undertaken using a fully annular test facility which incorporates a single stage axial flow compressor, diffuser and flame tube. Measurements have been made of the flow field, and its frequency content, within the dump cavity. Furthermore, the stagnation pressure presented to the core, outer and dome swirler passages of a fuel injector has been obtained for different circumferential positions of the upstream OGV/pre-diffuser assembly. These pressure variations, amounting to as much as 20% of the pressure drop across the fuel injector, also affect the flow field immediately downstream of the injector. In addition, general variations in pressure around the fuel injector have also been observed due to, for example, the fuel injector position relative to pre-diffuser exit and the flame tube cowl.

Effect of Particle Residence Time on Particle Dispersion in a Plane Mixing Layer

1993 ◽  
Vol 115 (4) ◽  
pp. 751-759 ◽  
Author(s):  
Tsuneaki Ishima ◽  
Koichi Hishida ◽  
Masanobu Maeda
Keyword(s):  
Gas Phase ◽  
Residence Time ◽  
Time Scale ◽  
Characteristic Time ◽  
Mixing Layer ◽  
Particle Dispersion ◽  
Laser Doppler Velocimeter ◽  
Characteristic Time Scale ◽  
Two Phase ◽  
Particle Residence Time

A particle dispersion has been experimentally investigated in a two-dimensional mixing layer with a large relative velocity between particle and gas-phase in order to clarify the effect of particle residence time on particle dispersion. Spherical glass particles 42, 72, and 135 μm in diameter were loaded directly into the origin of the shear layer. Particle number density and the velocities of both particle and gas phase were measured by a laser Doppler velocimeter with modified signal processing for two-phase flow. The results confirmed that the characteristic time scale of the coherent eddy apparently became equivalent to a shorter characteristic time scale due to a less residence time. The particle dispersion coefficients were well correlated to the extended Stokes number defined as the ratio of the particle relaxation time to the substantial eddy characteristic time scale which was evaluated by taking account of the particle residence time.

Optimal Control of Turbine Engines

1979 ◽  
Vol 101 (2) ◽  
pp. 117-126 ◽  
Author(s):  
R. L. DeHoff ◽  
W. Earl Hall
Keyword(s):  
Optimal Control ◽  
Optimal Design ◽  
Control Design ◽  
Multivariable Control ◽  
Turbine Engines ◽  
Linear Modeling ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Design Procedures ◽  
Modeling Techniques

Multivariable control design for turbine engines has been studied for over 20 years. In the last 10 years, the application of linear, optimal design techniques has produced a number of turbine engine controllers. A group of these design procedures is described and a discussion of the procedures’ performance, complexity and implementation is presented. The design of a full-envelope controller for the F100 turbofan engine based on linear, optimal synthesis and locally linear modeling techniques is discussed. A perspective of optimal control design for turbine engines is presented and the future is examined.

Determination of Thermoacoustic Response in a Demonstrator Gas Turbine Engine

2000 ◽  
Author(s):  
C. A. Arana ◽  
B. Sekar ◽  
M. A. Mawid
Keyword(s):  
Experimental Investigation ◽  
Gas Turbine ◽  
Analytical Model ◽  
Pressure Fluctuations ◽  
Gas Turbine Engine ◽  
Area Ratio ◽  
Fuel Injector ◽  
Acoustic Response ◽  
Turbine Engine ◽  
Discharge Area

This paper describes an analytical and experimental investigation to obtain the thermoacoustic response of a demonstrator gas turbine engine combustor. The combustor acoustic response for two different fuel injector design configurations was measured. It was found that the combustor maximum peak to peak pressure fluctuations were 0.6 psi to 2 psi for configuration A and B respectively. Based on the measured acoustic response, another experimental investigation was conducted to identify the design features in configuration B that caused the increase in the acoustic response. The data showed that by changing the fuel injector swirler’s vane to inner passage discharge area ratio, the engine acoustic response could be lowered to an acceptable level. A simplified analytical model based on the lumped-parameter approach was then developed to investigate the effect of geometrical changes upon the engine response. The analytical model predicted the fuel injector/swirlers acoustic response as a function of the swirlers inner passage discharge area ratio and frequency. The predictions were consistent with the experimental observations, in particular, it was predicted that as the area ratio was increased, the system reactance was decreased and as a result the system changed from a damping to an amplifying system.

Study of Oil Film Heat Transfer in Gas Turbine Engine Bearing Chamber

2021 ◽  
Author(s):  
Illia Petukhov ◽  
Taras Mykhailenko ◽  
Oleksii Lysytsia ◽  
Artem Kovalov
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Flow Core ◽  
Two Phase ◽  
Turbine Engine ◽  
Oil Film ◽  
Phase Medium ◽  
Engine Bearing

Abstract A clear understanding of the heat transfer processes in a gas turbine engine bearing chamber at the design stage makes it possible to properly design the lubrication and sealing systems and ensure the future bearing safe operation. The heat transfer coefficient (HTC) calculated based on the classical Newton-Richman equation is widely used to represent the heat transfer data and useful for the thermal resistance analysis. However, this approach is only formally applicable in the case of a two-phase medium. While there is a need to model a two-phase medium, setting the flow core temperature correctly in the Newton-Richman equation is an issue that is analyzed in this study. The heat from the flow core is transferred to the boundary of the oil film on the bearing chamber walls by an adjacent air and precipitating droplets. The analysis showed that droplet deposition plays a decisive role in this process and significantly intensifies the heat transfer. The main contribution to the thermal resistance of internal heat transfer is provided by the oil film. In this regard, the study considers the issues of the bearing chamber workflow modeling allowing to determine the hydrodynamic parameters of the oil film taking into account air and oil flow rates and shaft revolutions. The study also considers a possibility to apply the thermohydraulic analogy methods for the oil film thermal resistance determination. The study presents practical recommendations for process modeling in the bearing chamber.

scholarly journals Rapid Liquid Fuel Mixing for Lean-Burning Combustors: Low-Power Performance

2001 ◽  
Vol 123 (3) ◽  
pp. 574-579 ◽  
Author(s):  
M. Y. Leong ◽  
C. S. Smugeresky ◽  
V. G. McDonell ◽  
G. S. Samuelsen
Keyword(s):  
Low Power ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Direct Injection ◽  
Fuel Injector ◽  
Power Performance ◽  
Lean Burn ◽  
Engine Operation ◽  
Turbine Engine ◽  
Lean Direct Injection

Designers of advanced gas turbine combustors are considering lean direct injection strategies to achieve low NOx emission levels. In the present study, the performance of a multipoint radial airblast fuel injector Lean Burn injector (LBI) is explored for various conditions that target low-power gas turbine engine operation. Reacting tests were conducted in a model can combustor at 4 and 6.6 atm, and at a dome air preheat temperature of 533 K, using Jet-A as the liquid fuel. Emissions measurements were made at equivalence ratios between 0.37 and 0.65. The pressure drop across the airblast injector holes was maintained at 3 and 7–8 percent. The results indicate that the LBI performance for the conditions considered is not sufficiently predicted by existing emissions correlations. In addition, NOx performance is impacted by atomizing air flows, suggesting that droplet size is critical even at the expense of penetration to the wall opposite the injector. The results provide a baseline from which to optimize the performance of the LBI for low-power operation.

LDV measurements of an air-solid two-phase flow in a vertical pipe

1984 ◽  
Vol 139 ◽  
pp. 417-434 ◽  
Author(s):  
Yutaka Tsuji ◽  
Yoshinobu Morikawa ◽  
Hiroshi Shiomi
Keyword(s):  
Two Phase Flow ◽  
Laser Doppler Velocimeter ◽  
Medium Size ◽  
Phase Flow ◽  
Small Particles ◽  
Vertical Pipe ◽  
Two Phase ◽  
Air Turbulence ◽  
Large Particles ◽  
Particle Velocities

Measurements of air and solid-particle velocities were made in a vertical pipe two-phase flow by the use of a laser-Doppler velocimeter (LDV). Five kinds of plastic particles, diameters of which ranged from about 3 mm to 200 μm, were transported in a vertical pipe of 30 mm inner diameter. It was found that, the smaller the particle size, the flatter was the mean air velocity distribution for the same mass flow ratio of solids to air. Large particles increased air turbulence throughout the pipe section, while small particles reduced it. Both effects of promotion and suppression of turbulence were observed at the same time in the presence of particles of medium size, that is, the turbulence was increased around the pipe centre and reduced near the wall. The frequency spectrum of air turbulence normalized by the turbulence intensity was not changed by the large particles. In the presence of the small particles, the higher-frequency parts of the spectrum increased.

Three Component Velocity Field Measurements in the Stagnation Region of a Film Cooled Turbine Vane

2001 ◽  
Author(s):  
Marc D. Polanka ◽  
J. Michael Cutbirth ◽  
David G. Bogard
Keyword(s):  
Field Measurements ◽  
The Other ◽  
Test Facility ◽  
Laser Doppler Velocimeter ◽  
Stagnation Region ◽  
Turbine Engine ◽  
Mainstream Flow ◽  
Turbine Vane ◽  
Component Velocity ◽  
Very High

The showerhead region of a film cooled turbine vane in a gas turbine engine involves a complex interaction between mainstream flow and coolant jets. This flow field was studied using three-component laser Doppler velocimeter measurements in a simulated turbine vane test facility. Measurements were focused around the stagnation row of holes. Low and high mainstream turbulence conditions were used. The spanwise orientation of the coolant jets, typical for showerhead coolant holes, had a dominating effect. Very high levels of turbulence were generated by the mainstream interaction with the coolant jets. Furthermore, this turbulence was highly anisotropic, with the spanwise component of the turbulent fluctuations being twice as large as the other components. Finally, there was an interaction of the high mainstream turbulence with the coolant injection resulting in increased turbulence levels for the spanwise velocity component, but had little effect on the other velocity components.

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