Gas Turbine Technology
Gas turbines are a versatile, cost-effective source of electricity, mechanical power, and propulsion. Gas turbines continually challenge engineers to design, construct, and operate reliable and efficient turbines that meet market needs and respect the environment. Southwest Research Institute (SwRI) works with users, suppliers, and manufacturers of gas turbines, providing technical services, expertise, and research facilities to meet the challenge. Our broad range of capabilities includes:
The Institute's gas turbine materials technology program spans super-alloys, including directionally solidified and single crystal alloys, coatings, titanium alloys, composites, ceramics, intermetallics, and polymers, as well as conventional ferrous and nonferrous materials. SwRI metallurgical laboratories provide scanning electron microscopy, transmission electron microscopy, acoustic microscopy, atomic force microscopy, optical microscopy, scanning Auger spectroscopy, energy dispersive spectroscopy, X-ray diffraction, and specimen preparation facilities.
Mechanical testing facilities include servo-hydraulic, servo-electric, creep, and impact machines, augmented by computerized control and data acquisition. The Institute can perform the most exacting high temperature testing, including thermo-mechanical fatigue, creep crack growth, and effects of aggressive environments. Standard and advanced fracture mechanics, fatigue, creep, and impact tests are conducted to ASTM standards over a temperature range from the cryogenic regime to more than 3,000 degrees Fahrenheit (1,650 degrees Celsius). SwRI designs and assembles specialized test equipment to meet unique test requirements.
SwRI conducts metallurgical failure analyses on a wide range of
gas turbine materials and equipment. The Institute responds rapidly to field failures and
the need for timely analysis, and interacts with OEMs and suppliers. Our experienced staff
uses extensive metallurgical facilities to identify failure mechanisms and root causes.
Analyses draw on the Institute's multidisciplinary capabilities in stress analysis, life
management, mechanical and vibration analysis, materials testing, and nondestructive
Life Management, Stress Analysis, and Structural Analysis
The Institute develops algorithms and computerized programs for life prediction, life management, and life extension of gas turbine engines to increase component usage, maximize engine availability, and reduce maintenance costs. We apply the most current technology, including finite element and boundary element methods, to the stress analysis of gas turbine components. The Institute is a pioneer in probabilistic structural mechanics, which integrates computational mechanics and probabilistic methods to manage distribution of material properties, dimensions, and loads. Computational facilities include a central VAX computer, distributed workstations, and access to CRAY supercomputers. Available numerical codes include ABAQUS, ANSYS, and NASTRAN.
The Institute continues to develop new techniques and improved equipment for nondestructive evaluation of gas turbines and jet engines. We apply acoustic emission, ultrasonics, eddy current, electric current perturbation, magnetic flux leakage, and radiometrics to detect flaws in turbines for power and propulsion. The Institute designs specialized sensors for difficult geometries or confined spaces and makes full use of computer-controlled scanning, data acquisition, and display to achieve efficient and reliable detection and discrimination.
Fluid Dynamics and Heat Transfer
Fluid dynamics, heat transfer, and fluid-structure interaction are essential disciplines to the effective design, application, and performance evaluation of gas turbines. The Institute maintains a variety of commercial and SwRI-developed computational fluid dynamics codes to meet specific needs. A number of flow facilities are used in conjunction with computational methods to support comprehensive simulation and understanding of fluid flows and their interactions with structures. Flow visualization techniques enhance this capability. Facilities include:
System and Component Testing
Optimum performance and reliability of gas turbines in aeropropulsion, electrical power generation, and compressor or pump drives is achieved by careful balancing of conflicting demands that include low seal leakage without rubs, low weight without excessive vibration, high temperatures with long life, and blades free of vibration over a range of flow and speed conditions. The ability to test components and systems is important to achieving this balance.
SwRI has a variety of vibration, flow, noise, and environmental qualification testing facilities that are effectively used, often under conditions of realistic pressure, flow, speed, and size, in a variety of applications of critical concern to users and manufacturers of gas turbines. Environmental test facilities investigate the effects of vibration, shock, temperature, fire, salt fog, and sand and dust erosion on components and systems. Institute analytical resources complement test facilities.
Gas Turbine Monitoring
Gas turbines are the power source of choice in many applications for mechanical drive of machinery and for electrical power generation. When aero-derivative or large industrial gas turbines experience mechanical vibration, unsatisfactory performance, surge, stall, or thermal distortion, there is need for effective remedies applied on-site. SwRI has developed capabilities for measuring, acquiring, and analyzing the parameters critical to defining and correcting such problems. The Institute's remote data acquisition optimizes the testing process that can require weeks or months to assure coverage of varied operating conditions. SwRI provides all equipment needed on-site, with rapid response, to solve critical availability problems.
On-site testing is complemented by in-house capabilities for analysis of bearing dynamics, critical speeds, unbalance response, stability, and performance.
Testing, Diagnosis, and Support
Southwest Research Institute control, electronic, manufacturing, and performance capabilities provide broad support for turbine engine design, manufacture, inspection, test, and maintenance. Services include:
SwRI developed computer-based training for the operation and maintenance of large combustion turbines for the Electric Power Research Institute. Using digital video interactive (DVIŽ) computers, the course takes operators from cold shutdown conditions through pre-start, cranking, acceleration, synchronization, and load for the Westinghouse 501 gas turbine. A tutorial on the turbine's fuel system is under development.
SwRI instructional designers integrate DVIŽ with other advanced technologies to complete a dynamic informational resource for diagnostic training, visual databases, post disturbance analysis, and blade inspection. These resources can be applied as on-site training.
The Institute applies artificial intelligence techniques to the gas turbine industry. A number of knowledge-based, or expert, systems has been developed to support the maintenance and life assessment of gas turbine engines, including a system used to recommend protective coatings for gas turbines. Another SwRI system predicts the remaining life of gas turbine nozzle vanes, including estimated crack length, number of hours remaining, and the number of starts left for the nozzle. These systems run on PCs as well as larger computers.
Air Pollution Control
The many emissions produced by turbines are of great concern environmentally. The Institute has developed, quantified, and validated procedures to characterize and measure regulated emissions that include NOx, SOx, CO, CO2, O2, total hydrocarbons, particulates, and more than 20 unregulated emissions. Typical projects involve:
On-site tests of propulsion and stationary turbines are performed conveniently with a mobile emissions laboratory designed and constructed by SwRI that provides continuous hydrocarbon, CO, NOx, CO2, and O2 analysis, with additional capabilities for individual hydrocarbon, smoke, and particulate analysis.
Fuels, Lubricants, and Combustion Technology
The Institute, through fundamental and applied research, seeks to better understand how physical and chemical properties of fuels influence emissions, performance, and durability of engines and fuel systems. SwRI programs support military and civilian aviation and have additional applications for marine and stationary gas turbines.
Expertise is also directed to solving problems created by high temperature requirements that high performance engines, aircraft, and missiles will place on future fuels, lubricants, and other fluids. Research, development, testing, and evaluation capabilities range from production of test fuels to development of special laboratory and full-scale test rigs to address combustion and non-combustion problems. The program is supported by an analytical chemistry laboratory and a staff experienced in combustion, mechanical and chemical engineering, chemistry, chemical kinetics, and rheology.
Advanced Materials and Technology
The Institute's vigorous multi-disciplinary gas turbine research and development program, both internally funded and externally sponsored, addresses new analysis methods, processes, materials, and advanced measurement techniques to benefit past, present, and future gas turbines and their applications.This brochure was published in June 1996. For more information, contact the appropriate Institute staff member.