GETRAN: A Generic, Modularly Structured Computer Code for Simulation of Dynamic Behavior of Aero- and Power Generation Gas Turbine Engines

1994 ◽  
Vol 116 (3) ◽  
pp. 483-494 ◽  
Author(s):  
M. T. Schobeiri ◽  
M. Attia ◽  
C. Lippke
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Nasa Lewis Research ◽  
Gas Turbine Engines ◽  
Exit Nozzle ◽  
Nonlinear Dynamic Behavior

The design concept, the theoretical background essential for the development of the modularly structured simulation code GETRAN, and several critical simulation cases are presented in this paper. The code being developed under contract with NASA Lewis Research Center is capable of simulating the nonlinear dynamic behavior of single- and multispool core engines, turbofan engines, and power generation gas turbine engines under adverse dynamic operating conditions. The modules implemented into GETRAN correspond to components of existing and new-generation aero- and stationary gas turbine engines with arbitrary configuration and arrangement. For precise simulation of turbine and compressor components, row-by-row diabatic and adiabatic calculation procedures are implemented that account for the specific turbine and compressor cascade, blade geometry, and characteristics. The nonlinear, dynamic behavior of the subject engine is calculated solving a number of systems of partial differential equations, which describe the unsteady behavior of each component individually. To identify each differential equation system unambiguously, special attention is paid to the addressing of each component. The code is capable of executing the simulation procedure at four levels, which increase with the degree of complexity of the system and dynamic event. As representative simulations, four different transient cases with single- and multispool thrust and power generation engines were simulated. These transient cases vary from throttling the exit nozzle area, operation with fuel schedule, rotor speed control, to rotating stall and surge.

scholarly journals GETRAN: A Generic, Modularly Structured Computer Code for Simulation of Dynamic Behavior of Aero- and Power Generation Gas Turbine Engines

1993 ◽  
Author(s):  
T. Schobeiri ◽  
M. Abouelkheir ◽  
C. Lippke
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Nasa Lewis Research ◽  
Gas Turbine Engines ◽  
Exit Nozzle ◽  
Nonlinear Dynamic Behavior

The design concept, the theoretical background essential for the development of the modularly structured simulation code GETRAN, and several critical simulation cases are presented in this paper. The code being developed under contract with NASA Lewis Research Center is capable of simulating the nonlinear dynamic behavior of single- and multi-spool core engines, turbofan engines, and power generation gas turbine engines under adverse dynamic operating conditions. The modules implemented into GETRAN correspond to components of existing and new generation aero- and stationary gas turbine engines with arbitrary configuration and arrangement. For precise simulation of turbine and compressor components, row-by-row diabatic and adiabatic calculation procedures are implemented that account for the specific turbine and compressor cascade, blade geometry, and characteristics. The nonlinear, dynamic behavior of the subject engine is calculated solving a number of systems of partial differential equations, which describe the unsteady behavior of each component individually. To unambiguously identify each differential equation system, special attention is paid to the addressing of each component. The code is capable of executing the simulation procedure at four levels which increase with the degree of complexity of the system and dynamic event. As representative simulations, four different transient cases with single- and multi-spool thrust and power generation engines were simulated. These transient cases vary from throttling the exit nozzle area, operation with fuel schedule, rotor speed control, to rotating stall and surge.

Fuel Flexibility in LM2500 and LM6000 Dry Low Emission Engines

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
John Blouch ◽  
Hejie Li ◽  
Mark Mueller ◽  
Richard Hook
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Inert Gases ◽  
Effect Of Temperature ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Kinetics Analysis ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Commercial Operation

The LM2500 and LM6000 dry-low-emissions aeroderivative gas turbine engines have been in commercial service for 15 years and have accumulated nearly 10 × 106 hours of commercial operation. The majority of these engines utilize pipeline quality natural gas predominantly comprised of methane. There is; however, increasing interest in nonstandard fuels that contain varying levels of higher hydrocarbon species and/or inert gases. This paper reports on the demonstrated operability of LM2500 and LM6000 DLE engines with nonstandard fuels. In particular, rig tests at engine conditions were performed to demonstrate the robustness of the dual-annular counter-rotating swirlers premixer design, relative to flameholding with fuels containing high ethane, propane, and N2 concentrations. These experiments, which test the ability of the hardware to shed a flame introduced into the premixing region, have been used to expand the quoting limits for LM2500 and LM6000 gas turbine engines to elevated C2+ levels. In addition, chemical kinetics analysis was performed to understand the effect of temperature, pressure, and fuel compositions on flameholding. Test data for different fuels and operating conditions were successfully correlated with Damkohler number.

Fuel Flexibility in LM2500 and LM6000 Dry Low Emission Engines

2011 ◽  
Author(s):  
John Blouch ◽  
Hejie Li ◽  
Mark Mueller ◽  
Richard Hook
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Inert Gases ◽  
Effect Of Temperature ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Kinetics Analysis ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Commercial Operation

The LM2500 and LM6000 dry-low-emissions (DLE) aeroderivative gas turbine engines have been in commercial service for 15 years and have accumulated nearly 10 million hours of commercial operation. The majority of these engines utilize pipeline quality natural gas predominantly comprised of methane. There is, however, increasing interest in nonstandard fuels that contain varying levels of higher hydrocarbon species and/or inert gases. This paper reports on the demonstrated operability of LM2500 and LM6000 DLE engines with nonstandard fuels. In particular, rig tests at engine conditions were performed to demonstrate the robustness of the dual-annular counter-rotating swirlers (DACRS) premixer design, relative to flameholding with fuels containing high ethane, propane, and N2 concentrations. These experiments, which test the ability of the hardware to shed a flame introduced into the premixing region, have been used to expand the quoting limits for LM2500 and LM6000 gas turbine engines to elevated C2+ levels. In addition, chemical kinetics analysis was performed to understand the effect of temperature, pressure, and fuel compositions on flameholding. Test data for different fuels and operating conditions were successfully correlated with Damkohler number.

scholarly journals Approaches to the Prevaporized-Premixed Combustor Concept for Gas Turbines

1975 ◽  
Author(s):  
L. J. Spadaccini ◽  
E. J. Szetela
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Bluff Body ◽  
Porous Plate ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Operational Conditions ◽  
Lean Combustion

An experimental investigation was performed to evaluate a combustor concept which is applicable to gas turbine engines and is believed to offer valuable pollution control advantages relative to the conventional liquid-fuel-spray approach. It involves fuel prevaporization, premixing and lean combustion and may be applied to the design of combustors for aircraft, industrial or automotive powerplants. Two types of bluff-body flameholders, viz. porous-plate and drilled-plate, were evaluated for use as flame stabilizers within the combustor. Tests were conducted under sets of steady-state operational conditions corresponding, respectively, to applications in a low-pressure regenerative-cycle and high-pressure nonregenerative-cycle automobile gas turbine engines. The data acquired can be used to design gas turbine combustors having predicted performance characteristics which are better than those required to meet the most stringent automobile emissions regulations of the Federal “Clean Air Act.” Fuel prevaporization can be accomplished either externally, prior to admission into the engine airstream, or internally by the airstream itself. In support of the prevaporization concept, the feasibility of vaporizing No 2 fuel oil in a heat exchanger which is external to the engine was investigated. Tests conducted at representative operating conditions indicated that a deposit of 0.01 0-in. thickness was collected on the vaporizer wall after 50 hr of operation. A much shorter period of cleaning with hot air was sufficient to remove the deposit.

Prediction of CO Emission Index for Aviation Gas Turbine Combustor Using Flamelet Generated Manifold Combustion Model

2021 ◽  
Author(s):  
Saurabh Patwardhan ◽  
Pravin Nakod ◽  
Stefano Orsino ◽  
Rakesh Yadav ◽  
Fang Xu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Combustion Model ◽  
Gas Turbine Engines ◽  
Gas Turbine Combustor ◽  
Flamelet Generated Manifold ◽  
Emission Index ◽  
Co Emission

Abstract Carbon monoxide (CO) has been identified as one of the regulated pollutants and gas turbine manufacturers target to reduce the CO emission from their gas turbine engines. CO forms primarily when carbonous fuels are not burnt completely, or products of combustion are quenched before completing the combustion. Numerical simulations are effective tools that allow a better understanding of the mechanisms of CO formation in gas turbine engines and are useful in evaluating the effect of different parameters like swirl, fuel atomization, mixing etc. on the overall CO emission for different engine conditions like idle, cruise, approach and take off. In this paper, a thorough assessment of flamelet generated manifold (FGM) combustion model is carried out to predict the qualitative variation and magnitude of CO emission index with the different configurations of a Honeywell test combustor operating with liquid fuel under idle condition, which is the more critical engine condition for CO emission. The different designs of the test combustor are configured in such a way that they yield different levels of CO and hence are ideal to test the accuracy of the combustion model. Large eddy simulation (LES) method is used for capturing the turbulence accurately along with the FGM combustion model that is computationally economical compared to the detailed/reduced chemistry modeling using finite rate combustion model. Liquid fuel spray breakup is modeled using stochastic secondary droplet (SSD) model. Four different configurations of the aviation gas turbine combustor are studied in this work referring to earlier work by Xu et al. [1]. It is shown that the FGM model can predict CO trends accurately. The other global parameters like exit temperature, NOx emissions, pattern factor also show reasonable agreement with the test data. The sensitivity of the CO prediction to the liquid fuel droplet breakup model parameters is also studied in this work. Although the trend of CO variation is captured for different values of breakup parameters, the absolute magnitude of CO emission index differs significantly with the change in the values of breakup parameters suggesting that the spray has a larger impact on the quantitative prediction of CO emission. An accurate prediction of CO trends at idle conditions using FGM model extends the applicability of FGM model to predict different engine operating conditions for different performance criteria accurately.

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