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.

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 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 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.

Complex 3D Measuring by Multiple Laser Scanning of Automotive Parts

2013 ◽  
Vol 837 ◽  
pp. 511-516
Author(s):  
Adrian Catalin Voicu ◽  
Gheorghe I. Gheorghe
Keyword(s):  
Reverse Engineering ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Correct Choice ◽  
3D Scanning ◽  
Single Step ◽  
Graph Representation ◽  
Scanning System ◽  
Production Environment ◽  
Virtual Design

For over 20 years the term"three-dimensional scan"(3D) showed the world the possibilities of virtual design, simulation, or reverse engineering. 3D scanning is also known as 3D digitizing, the name coming from the fact that this is a process that uses a contact or non-contact digitizing probe to capture the objects form and recreate them in a virtual workspace through a very dense network of points (xyz) as a 3D graph representation. Until recently, digitization was limited by the speed of the scan head and the correct choice of the probing system, type of scanned piece and budget for the purchase or develops the scanning system. With the evolution of technology appeared a number of new techniques that tend to improve the properties of classical methods. Even if intended for copying or geometrical control, or rather virtual geometric modelling or product realization, there are two groups of technologies: with contact (classical methods with probes) or without contact (laser, optical or combination). Most automotive manufacturers currently use 3D scan metrology based on optical or laser systems to validate products quality. The pieces are initially measured by 3D scanning then they are compared with the designed model (CAD file) using a specialized software. By this comparison producer can interfere very quickly in the manufacturing process to remove the cause of defects, this technique being called Reverse Engineering (RE). There are many variables that affect accuracy of laser scanning and therefore the quality of information: reflectance of surface, colour object, recesses, openings narrow and sharp edges can be difficult to scan. This accuracy may vary from micron to millimetre and the acquisitions size from a few points to several thousand points per second. The overall accuracy of a 3D acquisition system depends above all on the sensors precision and on the acquisition device (acquisition with contact) or acquisition structure (acquisition without contact). In a perfect world or in an integrated production environment, 3D measuring systems should be able to measure all the necessary parameters in a single step without errors, and to render the results in the same way to the manufacturing networks equipped with computers, in formats useful for machines control and processes management.

Reverse Engineering Physical Models Employing Wrap-Around B-Spline Surfaces and Quadrics

1996 ◽  
Vol 210 (2) ◽  
pp. 147-157 ◽  
Author(s):  
D J Weir ◽  
M J Milroy ◽  
C Bradley ◽  
G W Vickers
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Surface Fitting ◽  
Physical Models ◽  
Scanning System ◽  
Cad Model ◽  
Three Dimensional Model ◽  
B Spline

Reverse engineering involves digitizing a three-dimensional model or part, by means of a tactile or non-contact optical sensor, converting the data to a CAD (computer aided design) database description and manufacturing by CNC (computer numerical controlled) machines. This paper demonstrates an effective approach to the reverse engineering of physical models by employing a three-dimensional laser scanning system in conjunction with surface-fitting software developed by the authors. Accurate surface data are collected by the laser scanner and then input to the surface-fitting software. Surface entities such as B-spline and quadric functions are employed to build the CAD model. The CAD model is compatible with popular design and manufacturing software packages. A telephone receiver is used to illustrate the efficiency of the process.

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