The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

Andre Romier - One of the best experts on this subject based on the ideXlab platform.

  • Small Gas Turbine technology
    Applied Thermal Engineering, 2004
    Co-Authors: Andre Romier
    Abstract:

    Abstract Small Gas Turbine Technology: Small Gas Turbine, in the power range up to 500 kW, requires a recuperated thermodynamic cycle to achieve an electrical efficiency of about 30%. This efficiency is the optimum, which is possible for a cycle pressure ratio of about 4–1. The cycle airflow is function of the power requirement. To increase the efficiency, in view to reduce the CO 2 emission, it is mandatory to develop a more efficient thermodynamic cycle. Different thermodynamic cycles were examined and the final choice was made for an Intercooled, Recuperated cycle. The advantage of this cycle, for the same final electrical efficiency of about 35%, is the Smaller cycle airflow, which is the most dimensional parameter for the important components as the heat exchanger recuperator and the combustion chamber. In parallel with the thermodynamic cycle it is necessary to develop the High Speed Alternator technology, integrated on the same shaft that the Gas Turbine rotating components, to achieve the constant efficiency at part loads, from 50% up to 100%, by the capacity to adjust the engine speed at the required load. To satisfy the stringent requirement in pollutant emissions of NO x and CO, the catalytic combustion system is the most efficient and this advance technology has to be proven. The major constraints for the Small Gas Turbine technology development are the production cost and the maintenance cost of the unit. In the power range of 0–500 kW the Gas Turbine technology is in competition with Small reciprocating engines, which are produced in large quantity for automotive industry, at a very low production cost.

Hooshang Heshmat - One of the best experts on this subject based on the ideXlab platform.

  • Small Gas Turbine Engine Operating With High-Temperature Foil Bearings
    ASME Conference Proceedings, 2006
    Co-Authors: Hooshang Heshmat, Michael J. Tomaszewski, James F Walton Ii
    Abstract:

    A 134 Newton thrust class, 120,000 rpm turbojet was redesigned to incorporate a high-temperature compliant foil bearing aft of the Turbine rotor and a compliantly mounted ball bearing forward of the centrifugal compressor--cold section. Two rotor-bearing system configurations were evaluated, one for operation above the bending critical speed and one for rigid rotor operation. Required characteristics for the foil bearing and ball bearing equipped with compliant foil damper mount were determined through a series of design tradeoff studies evaluating critical speeds and system stability. Following the design studies, the necessary hardware was fabricated, the engine assembled and operation to full speed achieved. Engine speed, rotor vibrations, compressor discharge pressure, exhaust Gas temperature, thrust and fuel consumption were all recorded for both a baseline fluid lubricated ball bearing supported engine and the new turbojet engine using the hybrid foil bearing support system. Issues related to high-speed operation above the bending critical speed are identified and recommendations offered. Engine test data show that approximately 10% less fuel is consumed by the hybrid foil bearing mount system than the baseline conventional design. It is also shown that the foil bearing life was longer than the ball bearing life even though the foil bearing operated in the exhaust Gas stream at temperatures exceeding 800$^rc$C. The results of this program demonstrate the feasibility of developing a completely oil-free foil bearing Gas Turbine engine.

  • Performance of a Complaint Foil Seal in a Small Gas Turbine Engine Simulator Employing a Hybrid Foil/Ball Bearing Support System
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS. The experimental results indicate superior performance of the CFS over the two other types of seals. Unlike brush seal, CFS showed no evidence of rub or induced wear on the journal or seal surface. Presented at the 56th Annual Meeting Orlando, Florida May 20?24, 2001\nOperation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS. The experimental results indicate superior performance of the CFS over the two other types of seals. Unlike brush seal, CFS showed no evidence of rub or induced wear on the journal or seal surface. Presented at the 56th Annual Meeting Orlando, Florida May 20?24, 2001

  • performance of a complaint foil seal in a Small Gas Turbine engine simulator employing a hybrid foil ball bearing support system
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS....

  • Performance of a Complaint Foil Seal in a Small Gas Turbine Engine Simulator Employing a Hybrid Foil/Ball Bearing Support System
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS....

Mohsen Salehi - One of the best experts on this subject based on the ideXlab platform.

  • Performance of a Complaint Foil Seal in a Small Gas Turbine Engine Simulator Employing a Hybrid Foil/Ball Bearing Support System
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS. The experimental results indicate superior performance of the CFS over the two other types of seals. Unlike brush seal, CFS showed no evidence of rub or induced wear on the journal or seal surface. Presented at the 56th Annual Meeting Orlando, Florida May 20?24, 2001\nOperation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS. The experimental results indicate superior performance of the CFS over the two other types of seals. Unlike brush seal, CFS showed no evidence of rub or induced wear on the journal or seal surface. Presented at the 56th Annual Meeting Orlando, Florida May 20?24, 2001

  • performance of a complaint foil seal in a Small Gas Turbine engine simulator employing a hybrid foil ball bearing support system
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS....

  • Performance of a Complaint Foil Seal in a Small Gas Turbine Engine Simulator Employing a Hybrid Foil/Ball Bearing Support System
    Tribology Transactions, 2001
    Co-Authors: Mohsen Salehi, Hooshang Heshmat
    Abstract:

    Operation of a non-contact compliant Gas foil seal (CFS) in a high temperature hybrid dynamic simulator representative of a Small Gas Turbine engine spool is discussed. At the hot section of the simulator two oil-free components, a CFS and a compliant foil bearing (CFB) were mounted and at the cold (compressor) section of the simulator, an oil-mist lubricated ball bearing was installed. The preliminary numerical study on the fluid flow and thermal analysis of a CFS was discussed in the previous work by the authors. The experimental results for successful operation of the foil bearing and foil seal at temperatures up to 560 °C and speeds up to 55,000 rpm are presented. The surface of the CFS and CFB journals for high temperature tests were coated with PS304 solid lubricant film, developed by NASA The CFS performance at different operating speeds and temperatures and differential pressures was investigated. In a similar test, a leakage flow comparison was made among a labyrinth seal, a brush seal and a CFS....

Dieter Bernhard - One of the best experts on this subject based on the ideXlab platform.

  • Telemetry System Integrated in a Small Gas Turbine Engine
    Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2012
    Co-Authors: S.a. Long, Stephen L. Edney, Patrick A. Reiger, Michael W. Elliott, Frank Knabe, Dieter Bernhard
    Abstract:

    For the purpose of assessing combustion effects in a Small Gas Turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power Turbine rotor module. This assessment required measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gauges. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. As a result of space constraints, housing of the telemetry module was limited to placement in a hot section. To tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program.

  • Application of a Miniature Telemetry System in a Small Gas Turbine Engine
    Volume 3: Controls Diagnostics and Instrumentation; Education; Electric Power; Microturbines and Small Turbomachinery; Solar Brayton and Rankine Cycle, 2011
    Co-Authors: S.a. Long, Stephen L. Edney, Patrick A. Reiger, Michael W. Elliott, Frank Knabe, Dieter Bernhard
    Abstract:

    For the purpose of assessing combustion effects in a Small Gas Turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power Turbine rotor module. This assessment required measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gages. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. Due to space constraints, housing of the telemetry module was limited to placement in a hot section. In order to tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program.Copyright © 2011 by Rolls-Royce Corporation

Waldo A. Acosta - One of the best experts on this subject based on the ideXlab platform.

  • An efficient liner cooling scheme for advanced Small Gas Turbine combustors
    29th Joint Propulsion Conference and Exhibit, 1993
    Co-Authors: Marc D. Paskin, Hukam C. Mongia, Waldo A. Acosta
    Abstract:

    A joint Army/NASA program was conducted to design, fabricate, and test an advanced, Small Gas Turbine, reverse-flow combustor utilizing a compliant metal/ceramic (CMC) wall cooling concept. The objectives of this effort were to develop a design method (basic design data base and analysis) for the CMC cooling technique and then demonstrate its application to an advanced cycle, Small, reverse-flow combustor with 3000 F burner outlet temperature. The CMC concept offers significant improvements in wall cooling effectiveness resulting in a large reduction in cooling air requirements. Therefore, more air is available for control of burner outlet temperature pattern in addition to the benefits of improved efficiency, reduced emissions, and lower smoke levels. The program was divided into four tasks. Task 1 defined component materials and localized design of the composite wall structure in conjunction with development of basic design models for the analysis of flow and heat transfer through the wall. Task 2 included implementation of the selected materials and validated design models during combustor preliminary design. Detail design of the selected combustor concept and its refinement with 3D aerothermal analysis were completed in Task 3. Task 4 covered detail drawings, process development and fabrication, and a series of burner rig tests. The purpose of this paper is to provide details of the investigation into the fundamental flow and heat transfer characteristics of the CMC wall structure as well as implementation of the fundamental analysis method for full-scale combustor design.

  • Composite Matrix Cooling Scheme for Small Gas Turbine Combustors
    26th Joint Propulsion Conference, 1990
    Co-Authors: Marc D. Paskin, Phillip T. Ross, Hukam C. Mongia, Waldo A. Acosta
    Abstract:

    The design, manufacture, and testing of a compliant metal/ceramic (CMC) wall cooling concept-implementing combustor for Small Gas Turbine engines has been undertaken by a joint U.S. Army/NASA technology development program. CMC in principle promises greater wall cooling effectiveness than conventional designs and materials, thereby facilitating a substantial reduction in combustor cooling air requirements and furnishing greater airflow for the control of burner outlet temperature patterns as well as improving thermodynamic efficiency and reducing pollutant emissions and smoke levels. Rig test results have confirmed the projected benefits of the CMC concept at combustor outlet temperatures of the order of 2460 F, at which approximately 80 percent less cooling air than conventionally required was being employed by the CMC combustor.