scholarly journals Parametric Study of Flame Radiation Characteristics of a Tubular-Can Combustor

1983 ◽  
Author(s):  
Francis M. Humenik ◽  
Russell W. Claus ◽  
Geralyn M. Neely
Keyword(s):  
Radiant Heat ◽  
Radiation Detectors ◽  
Temperature Data ◽  
Operating Conditions ◽  
Spectral Radiation ◽  
Radiation Characteristics ◽  
Flame Radiation ◽  
Radiation Data ◽  
Fuel Nozzle ◽  
Hydrogen Fuels

A series of combustor tests were conducted with a tubular-can combustor to study flame radiation characteristics and effects with parametric variations in combustor operating conditions. Two alternate combustor assemblies using a different fuel nozzle were compared. Spectral and total radiation detectors were positioned at three stations along the length of the combustor can. Data were obtained for a range of pressures from 0.34 to 2.07 MPa (50 to 300 psia), inlet temperatures from 533 to 700K (500 to 800°F), for Jet A (13.9% hydrogen) and ERBS (12.9% hydrogen) fuels, and with fuel-air ratios nominally from 0.008 to 0.021. Spectral radiation data, total radiant heat flux data, and liner temperature data are presented to illustrate the flame radiation characteristics and effects in the primary, secondary, and tertiary combustion zones.

Effects of Fuel Nozzle Condition on Gas Turbine Combustion Chamber Exit Temperature Distributions

2010 ◽  
Author(s):  
Kristen Bishop ◽  
William Allan
Keyword(s):  
Combustion Chamber ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Operating Conditions ◽  
Spray Cone Angle ◽  
Mixing Processes ◽  
Spray Cone ◽  
Temperature Distributions ◽  
Fuel Nozzle ◽  
Exit Temperature

The effects of fuel nozzle condition on the temperature distributions experienced by the nozzle guide vanes have been investigated using an optical patternator. Average spray cone angle, symmetry, and fuel streaks were quantified. An ambient pressure and temperature combustion chamber test rig was used to capture exit temperature distributions and to determine the pattern factor. The rig tests matched representative engine operating conditions by matching Mach number, equivalence ratio, and fuel droplet size. It was observed that very small deviations (± 10° in spray cone angle) from a nominal distribution in the fuel nozzle spray pattern correlated to increases in pattern factor, apparently due to a degradation of mixing processes, which created larger regions of very high temperature core flow and smaller regions of cooler temperatures within the combustion chamber exit plane. The spray cone angle had the most measureable influence while the effects of spray roundness and streak intensity had slightly less influence. Comparisons were made with published studies conducted on the combustion chamber geometry, and recommendations were made for fuel nozzle inspections.

Effects of terrain conditions on the detailed spectral radiation characteristics of the space target

2019 ◽  
Vol 48 (12) ◽  
pp. 1213003
Author(s):  
陈 博 Chen Bo ◽  
穆 磊 Mu Lei ◽  
张 彪 Zhang Biao ◽  
许传龙 Xu Chuanlong
Keyword(s):  
Spectral Radiation ◽  
Radiation Characteristics ◽  
Space Target

The Correlation of Drop-Size Distributions in Fuel Nozzle Sprays—Part I: The Drop-Size/Volume-Fraction Distribution

1977 ◽  
Vol 99 (3) ◽  
pp. 309-314 ◽  
Author(s):  
H. C. Simmons
Keyword(s):  
Drop Size ◽  
Volume Fraction ◽  
Operating Conditions ◽  
Different Types ◽  
Median Diameter ◽  
Fraction Distribution ◽  
Fuel Nozzle ◽  
Drop Size Distributions ◽  
Mass Median ◽  
Mass Median Diameter

The paper presents data on the drop-size/volume-fraction distributions of sprays observed with a large number of gas-turbine fuel nozzles of different types including both pressure and air-atomizers, using a range of fuel viscosities, at a variety of operating conditions. The data were obtained by both optical and wax-droplet methods. It is shown that a universal nondimensional correlation can be established for all the fuel nozzles when the drop-size is normalized to the mass median diameter. The correlation enables prediction of the drop-size/volume-fraction distribution for a spray given only the mass median or Sauter mean diameter.

A Climatic Model of Solar Radiation and Temperature Change

1974 ◽  
Vol 4 (1) ◽  
pp. 25-38 ◽  
Author(s):  
Clayton H. Reitan
Keyword(s):  
Solar Radiation ◽  
Energy Budget ◽  
Temperature Data ◽  
Direct Solar Radiation ◽  
Response Ratio ◽  
Radiation Data ◽  
Long Term Trends ◽  
The 1960S ◽  
The Relationship

Mean monthly temperatures for the Northern Hemisphere were determined for the years 1955 through 1968 following the same procedures used by H. C. Willett and J. M. Mitchell, Jr., in their studies of long-term trends. It was found that the downward trend they reported starting in the 1940s continued, though interrupted, into the 1960s.The temperature data when combined with radiation data and other components of the hemispheric energy budget led to the formulation of the response ratio, the relationship between change in incoming solar radiation and change in temperature. When this response ratio was applied to the reported trends in direct solar radiation and to the decrease in direct solar radiation following the eruption of Agung in 1963, a probable cause-effect relationship was suggested.

Design Improvement Survey for NOx Emissions Reduction of a Heavy-Duty Gas Turbine Partially Premixed Fuel Nozzle Operating With Natural Gas: Numerical Assessment

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Alessandro Innocenti ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Matteo Cerutti ◽  
Gianni Ceccherini ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Turbulent Combustion ◽  
Operating Conditions ◽  
Combustion Model ◽  
Formation Mechanisms ◽  
Heavy Duty ◽  
Flamelet Generated Manifold ◽  
Fuel Nozzle ◽  
Partially Premixed ◽  
Heavy Duty Gas Turbine

A numerical investigation of a low NOx partially premixed fuel nozzle for heavy-duty gas turbine applications is presented in this paper. Availability of results from a recent test campaign on the same fuel nozzle architecture allowed the exhaustive comparison study presented in this work. At first, an assessment of the turbulent combustion model was carried out, with a critical investigation of the expected turbulent combustion regimes in the system and taking into account the partially premixed nature of the flame due to the presence of diffusion type pilot flames. In particular, the fluent partially premixed combustion model and a flamelet approach are used to simulate the flame. The laminar flamelet database is generated using the flamelet generated manifold (FGM) chemistry reduction technique. Species and temperature are parameterized by mixture fraction and progress variable. Comparisons with calculations with partially premixed model and the steady diffusion flamelet (SDF) database are made for the baseline configuration in order to discuss possible gains associated with the introduced dimension in the FGM database (reaction progress), which makes it possible to account for nonequilibrium effects. Numerical characterization of the baseline nozzle has been carried out in terms of NOx. Computed values for both the baseline and some alternative premixer designs have been then compared with experimental measurements on the reactive test rig at different operating conditions and different split ratios between main and pilot fuel. Numerical results allowed pointing out the fundamental NOx formation processes, both in terms of spatial distribution within the flame and in terms of different formation mechanisms. The obtained knowledge would allow further improvement of fuel nozzle design.

Radiative Heat Transfer Analysis of Railroad Bearings for Wayside Hot-Box Detector Optimization

2017 ◽  
Author(s):  
Arthur Mealer ◽  
Constantine Tarawneh ◽  
Stephen Crown
Keyword(s):  
Temperature Data ◽  
Operating Conditions ◽  
Heat Transfer Analysis ◽  
Infrared Sensor ◽  
Test Rig ◽  
Detection Systems ◽  
Railway Safety ◽  
Railroad Bearings ◽  
Railroad Bearing ◽  
The University

The railroad industry utilizes wayside detection systems to monitor the temperature of freight railcar bearings in service. The wayside hot-box detector (HBD) is a device that sits on the side of the tracks and uses a non-contact infrared sensor to determine the temperature of the train bearings as they roll over the detector. Various factors can affect the temperature measurements of these wayside detection systems. The class of the railroad bearing and its position on the axle relative to the position of the wayside detector can affect the temperature measurement. That is, the location on the bearing cup where the wayside infrared sensor reads the temperature varies depending on the bearing class (e.g., class K, F, G, E). Furthermore, environmental factors can also affect these temperature readings. The abovementioned factors can lead to measured temperatures that are significantly different than the actual operating temperatures of the bearings. In some cases, temperature readings collected by wayside detection systems did not indicate potential problems with some bearings, which led to costly derailments. Attempts by certain railroads to optimize the use of the temperature data acquired by these wayside detection systems has led to removal of bearings that were not problematic (about 40% of bearings removed were non-verified), resulting in costly delays and inefficiencies. To this end, the study presented here aims to investigate the efficacy of the wayside detection systems in measuring the railroad bearing operating temperature in order to optimize the use of these detection systems. A specialized single bearing dynamic test rig with a configuration that closely simulates the operating conditions of railroad bearings in service was designed and built by the University Transportation Center for Railway Safety (UTCRS) research team at the University of Texas Rio Grande Valley (UTRGV) for the purpose of this study. The test rig is equipped with a system that closely mimics the wayside detection system functionality and compares the infrared sensor temperature reading to contact thermocouple and bayonet temperature sensors fixed to the outside surface of the bearing cup. This direct comparison of the temperature data will provide a better understanding of the correlation between these temperatures under various loading levels, operating speeds, and bearing conditions (i.e. healthy versus defective), which will allow for an optimization of the wayside detectors. The impact on railway safety will be realized through optimized usage of current wayside detection systems and fewer nonverified bearings removed from service, which translates into fewer costly train stoppages and delays.

Spectral and Total Radiation Properties of Turbulent Hydrogen/Air Diffusion Flames

1987 ◽  
Vol 109 (1) ◽  
pp. 165-171 ◽  
Author(s):  
J. P. Gore ◽  
S.-M. Jeng ◽  
G. M. Faeth
Keyword(s):  
Diffusion Flames ◽  
Radiant Heat ◽  
Streamwise Velocity ◽  
Equilibrium Structure ◽  
Heat Fluxes ◽  
Laminar Flames ◽  
Spectral Radiation ◽  
Radiation Properties ◽  
Method Effects ◽  
Air Diffusion

A study of the structure and radiation properties of round turbulent hydrogen/air diffusion flames is described. Measurements were made of mean and fluctuating streamwise velocity, mean temperatures, species concentrations, spectral radiation intensities, and radiant heat fluxes. The measurements were used to evaluate predictions based on the laminar flamelet concept and narrow-band radiation models both ignoring (using mean properties) and considering (using a stochastic method) effects of turbulence/radiation interactions. State relationships found by correlating auxiliary measurements in laminar flames proved to be almost equivalent to conditions for local thermodynamic equilibrium. Structure and radiation predictions were reasonably good for present test conditions. Effects of turbulence/radiation interactions were significant for these flames, causing almost a 100 percent increase in spectral radiation intensities, in comparison to mean property predictions, upstream of the flame tip.

In‐Flight Far‐Field Measurement of Helicopter Impulsive Noise

1976 ◽  
Vol 21 (4) ◽  
pp. 2-16
Author(s):  
F. H. Schmitz ◽  
D. A. Boxwell
Keyword(s):  
High Speed ◽  
Impulsive Noise ◽  
Operating Conditions ◽  
Tape Recording ◽  
Far Field ◽  
Recording Equipment ◽  
Radiation Characteristics ◽  
Acoustic Data ◽  
Noise Radiation ◽  
The Subject

A new and highly successful method of collecting far‐field acoustic data radiated by helicopters in forward flight has been developed, utilizing a quiet aircraft flying in formation ahead of the subject helicopter. The lead aircraft, flown as an acoustic probe, was equipped with tape‐recording equipment and an external microphone. Spatial orientation of the helicopter with respect to the monitoring aircraft was achieved through visual flight reference. Far‐field acoustic data defining the impulsive noise radiation characteristics of the UH‐1H helicopter during high‐speed flight and partial ‐power descents have been gathered with this technique. Three distinct types of impulsive waveforms have been identified and correlated with helicopter steady operating conditions.

Risk-based Winterization for Vessels Operations in Arctic Environments

2013 ◽  
Vol 29 (04) ◽  
pp. 199-210 ◽  
Author(s):  
Ming Yang ◽  
Faisal I. Khan ◽  
Leonard Lye ◽  
Heri Sulistiyono ◽  
John Dolny ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Temperature Data ◽  
Operating Conditions ◽  
Hydrocarbon Exploration ◽  
The Arctic ◽  
Gas Industry ◽  
Arctic Regions ◽  
Exploration And Production

Because the oil and gas industry has an increasing interest in the hydrocarbon exploration and development in the Arctic regions, it becomes important to design exploration and production facilities that suit the cold and harsh operating conditions. In addition to well-established minimum class requirements for hull strengthening, winterization should be considered as a priority measure early in the design spiral for vessels operating in the Arctic environments. The development of winterization strategies is a challenging task, which requires a robust decision support approach. This article proposes a risk-based approach for the selection of winterization technologies and determination of winterization levels or requirements on a case-by-case basis. Temperature data are collected from climatology stations located in the Arctic regions. Loading scenarios are defined by statistical analysis of the temperature data to obtain probabilistic distributions for the loadings. Risk values are calculated under different loading scenarios. Based on the risk values, appropriate winterization strategies can be determined. A case study is used to demonstrate how the proposed approach can be applied to the identification of heating requirements for gangways.

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