Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations

2010 ◽  
Author(s):  
Clayton Kotzer ◽  
Marc LaViolette ◽  
William Allan ◽  
Asad Asghar
Keyword(s):  
Combustion Chamber ◽  
Temperature Profile ◽  
Laser Scanning ◽  
Reference Model ◽  
Ambient Pressure ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Scanning System ◽  
Geometric Deviations ◽  
Exit Temperature

The purpose of this continuing research was to investigate the effects of combustion chamber geometry on exit temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7 620 m (25,000 ft) by matching Mach number, equivalence ratio and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution temperature measurements were obtained in the combustion chamber exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating temperature for continuous cruise condition. Geometric deviations of both populations were compared to the reference model. The relationship between combustion chamber exit temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.

Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Clayton Kotzer ◽  
Marc LaViolette ◽  
William Allan ◽  
Asad Asghar
Keyword(s):  
Combustion Chamber ◽  
Temperature Profile ◽  
Laser Scanning ◽  
Reference Model ◽  
Ambient Pressure ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Scanning System ◽  
Geometric Deviations ◽  
Exit Temperature

The purpose of this continuing research was to investigate the effects of combustion chamber geometry on exit temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 kn) at 7620 m (25,000 ft) by matching Mach number, equivalence ratio, and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution temperature measurements were obtained in the combustion chamber exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating temperature for continuous cruise condition. Geometric deviations of both populations were compared with the reference model. The relationship between combustion chamber exit temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.

Effects of Combustion Chamber Geometry Upon Exit Temperature Profiles

2009 ◽  
Author(s):  
Clayton Kotzer ◽  
Marc LaViolette ◽  
William Allan
Keyword(s):  
Combustion Chamber ◽  
Laser Scanning ◽  
Reference Model ◽  
Ambient Pressure ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Scanning System ◽  
Geometric Deviations ◽  
Exit Temperature ◽  
Engine Operating Condition

The purpose of this research was to investigate the effects of combustion chamber geometry on exit temperature fields using an ambient pressure test rig. The apparatus contained a 120° sector of a combustion section of a Rolls Royce (previously Allison) T56-A-15 gas turbine engine. A thermocouple rake acquired high-resolution temperature measurements in the combustion chamber exit plane. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7620 m (25000ft) by matching the Mach number, the equivalence ratio and the Sauter mean diameter of the fuel spray. To quantify the geometric deviations of the combustion chamber specimens, which varied in service conditions, a three-dimensional laser scanning system was used. Combustion chamber geometric deviations were extracted through comparison of the scanned data to a reference model using the selected software. The relationship between combustion chamber exit temperature profile and geometric deviation was then compared. The main conclusion of this research was that small deviations from nominal dimensions in the dilution zone of the combustion chamber correlated to an increase in pattern factor. A decrease in the mixing of the products of combustion and dilution air was observed as damage in the dilution zone increased. This reduction in mixing created a more compact, higher temperature core flow. The results obtained from this research were compared to past studies.

CFD Analysis of the Combustion Chamber of a Commercial Aircraft Engine of Medium Thrust Class From a Maintenance Perspective

2017 ◽  
Author(s):  
Stefan Kuntzagk ◽  
Jörn Kraft ◽  
Ina Esemann
Keyword(s):  
Combustion Chamber ◽  
Temperature Profile ◽  
Measurement Errors ◽  
Burning Velocity ◽  
Combustion Model ◽  
Cfd Analysis ◽  
Hexahedral Mesh ◽  
Flow Topology ◽  
Geometrical Features ◽  
Exit Temperature

The combustion chamber of aircraft engines plays an important role in achieving the optimum performance during an engine overhaul. For long decades, it has been common understanding in the MRO business that a well overhauled compressor and turbine are required to get an engine with low SFC and high EGT margin. In recent work at Lufthansa Technik AG, a comprehensive CFD analysis of the combustion chamber showed that, in contrast to this, small geometrical features influence the mixing process in the combustion chamber and can have an effect on the exit temperature profile. This in turn can reduce the accuracy of the EGT measurement significantly and create measurement errors and misinterpretations of the real engine performance. In order to get insight into the flow topology, a very detailed digital model has been created using scans of the hardware available in the shop. Important geometrical features such as the cooling provisions and swirl creating components have been included in a very detailed manner with an efficient hexahedral mesh. The model includes the HPT vanes and the cooling flow extraction from the secondary cold flow. CFD results have been generated using the flow solver Ansys CFX 17.1, which is able to predict all relevant physical effects such as injection of liquid fuel, evaporation, and combustion of Jet A1 fuel using the Burning-Velocity combustion model. The flow in the combustion chamber shows large natural fluctuations. Subsequently, for each case a transient calculation has been carried out in order to allow an evaluation of the time-averaged flow field. Different geometrical features are investigated to predict the effect of geometry deviations on the exit temperature profile, e.g. the shape and size of the dilution holes. Finally along the example of two CFM56 engines it will be shown how the data obtained by the detailed CFD model is used to optimize work-scoping and maintenance procedures. On the two cases put forward the combination of extended test-cell instrumentation and detailed modeling enabled not only the identification but also the rectification of combustion chamber deviations. This in turn minimized the necessary work, whereas in the past combustion chamber issues often went unnoticed and consequently resulted in extensive additional work.

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.

scholarly journals POSSIBILITIES OF THE APPLICATION OF THREE-DIMENSIONAL TECHNOLOGIES AND MODERN TECHNOLOGICAL MEANS IN THE CRIME INVESTIGATION ACTIVITY

2018 ◽  
Vol 18 ◽  
pp. 98-105
Author(s):  
N. V. Pavliuk
Keyword(s):  
Digital Media ◽  
Technology Use ◽  
Laser Scanning ◽  
3D Model ◽  
Imaging System ◽  
3D Visualization ◽  
Three Dimensional ◽  
Scanning System ◽  
Crime Reconstruction ◽  
Technological Means

The issues related to the introduction of innovative methods, technologies and technological means in the investigation of crimes are considered. It is noted that one of the main directions of the development of Criminalistics is the assimilation of the virtual reality associated with computerization of spheres of life, implementation of modern technologies and their use in law enforcement. Technology use of laser scanning of terrain and objects resulting in 3D model is produced allows several times to increase informative value of data collected at the incident scene, provides a visual and convenient visualization in three-dimensional form. As against photo and video images, 3D model has a stereoscopic image and the ability to freely change the angle while viewing. Besides to scanning results can be stored on any digital media without the possibility of changes or adjustments. Attention is focused on the technological capabilities of 3D-visualization systems on examples of their use in foreign countries as technological means of capturing the situation of the scene and the subsequent of a crime reconstruction. Thus, using a portable three-dimensional imaging system for working with volumetric traces at a crime scene, it is possible to obtain accurate three-dimensional images of traces of protectors or footprints (shoes) on soil and snow. This system is an alternative to traditional methods of fixing evidence: photofixing and making plaster casts. Unlike other systems, new approach does not require the use of lasers. The expediency of expanding the range of 3D laser scanning system use in modern investigative and judicial practice of our state with the aim of increasing the level of provision of pre-trial investigation authorities with technological means and bringing it closer to European standards is argued.

Recognition and repairing of surface hole in three dimensional laser scanning system

2016 ◽  
Vol 9 (1) ◽  
pp. 114-121
Author(s):  
吕源治 LYU Yuan-zhi ◽  
孙 强 SUN Qiang ◽  
毕国玲 BI Guo-ling
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Scanning System ◽  
Laser Scanning System

3D Laser Scanner and its Application in Engineering Survey

2013 ◽  
Vol 671-674 ◽  
pp. 2111-2114
Author(s):  
Yan Ping Feng ◽  
Wei Guo Li ◽  
Li Bing Yang ◽  
Yan Li Gao ◽  
Wen Bin Li
Keyword(s):  
Laser Scanning ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Target Object ◽  
Scanning System ◽  
3 Dimensional ◽  
Working Principle ◽  
Laser Scanning System ◽  
Three Dimensional Space

3D laser scanning system is to use laser ranging principle to record intensively the 3D coordinates, reflectivity and texture information on the surface of the target object. It makes a real record of the three-dimensional space, which makes traditional measurement be released from the limit that couldn’t be exceeded in the past, and let the measurement precision up to a new level. At the same time, it has provided extensive researches with better help than ever. This paper mainly discusses the characteristics, working principle, application and future development of the ground 3 dimensional laser scanner.

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