scholarly journals Calculating gas turbine thermodynamic cycle using GateCycle TM software

2017 ◽  
Vol 20 (K5) ◽  
pp. 30-36
Author(s):  
Manh Duc Vu ◽  
Thang Huy Ha ◽  
Thang Trong Dao ◽  
Kien Trung Nguyen

Gas turbine engines are widely used in aviation and naval ships for their compactness and high mobility. In Vietnam, the researches and investigations for this type of engine are less interested. In this paper, the authors present methods of modeling and calculating gas turbine thermodynamic cycle by using the General Electric software – GateCycleTM. The results can be used for the study of gas turbine engines and for engine operation.

2020 ◽  
Vol 19 (4) ◽  
pp. 43-57
Author(s):  
H. H. Omar ◽  
V. S. Kuz'michev ◽  
A. O. Zagrebelnyi ◽  
V. A. Grigoriev

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.


Author(s):  
Craig R. Davison ◽  
A. M. Birk

A computer model of a gas turbine auxiliary power unit was produced to develop techniques for fault diagnosis and prediction of remaining life in small gas turbine engines. Due to the relatively low capital cost of small engines it is important that the techniques have both low capital and operating costs. Failing engine components were identified with fault maps, and an algorithm was developed for predicting the time to failure, based on the engine’s past operation. Simulating daily engine operation over a maintenance cycle tested the techniques for identification and prediction. The simulation included daily variations in ambient conditions, operating time, load, engine speed and operating environment, to determine the amount of degradation per day. The algorithm successfully adapted to the daily changes and corrected the operating point back to standard conditions to predict the time to failure.


Author(s):  
Matthew G. Hoffman ◽  
Richard J. DeCorso ◽  
Dennis M. Russom

The U.S. Navy has experienced problems with liquid fuel nozzles used on the Rolls Royce (formerly Allison) 501K series marine gas turbine engines. The 501K engines used by the U.S. Navy power Ship Service Gas Turbine Generators (SSGTGs) on a number of destroyer and cruiser class ships. Over roughly the last 25 years, 3 different nozzle designs have been employed, the latest and current nozzle being a piloted air blast design. The primary failure modes of these designs were internal fuel passage coking and external carbon deposits. The current piloted air blast design has a hard time replacement requirement of 1500 hours. This life is considered unacceptable. To improve fuel nozzle life, the Navy and Turbine Fuel Technologies (formerly Delavan) teamed in a fast track program to develop a new fuel nozzle with a target life of 5000 hours and 500 starts. As a result, an air assist/air blast nozzle was developed and delivered in approximately 6 months. In addition to the nozzle itself, a system was developed to provide assist air to the fuel nozzles to help atomize the fuel for better ignition. Nozzle sets and air assist systems have been delivered and tested at the NSWC Philadelphia LBES (Land Based Engineering Site). In addition, nozzle sets have been installed aboard operating ships for in-service evaluations. During the Phase one evaluation (July 2000 to June 2001) aboard USS Porter (DDG 78) a set of nozzles accumulated over 3500 hours of trouble free operation, indicating the target of 5000 hours is achievable. As of this writing these nozzles have in excess of 5700 hours. The improvements in nozzle life provided by the new fuel nozzle design will result in cost savings through out the life cycle of the GTGS. In fact, the evaluation nozzles are already improving engine operation and reliability even before the nozzles’ official fleet introduction. This paper describes the fuel nozzle and air assist system development program and results of OEM, LBES and fleet testing.


2018 ◽  
Vol 220 ◽  
pp. 03001
Author(s):  
Andrey Tkachenko ◽  
Ilia Krupenich ◽  
Evgeny Filinov ◽  
Yaroslav Ostapyuk

This article describes the multi-level approach to developing the virtual testing rig of gas turbine engines and power plants. The described virtual rig is developed on the basis of computer-aided system of thermogasdynamic calculations and analysis ASTRA, developed at Samara National Research University. Existing testing rig is widely used in educational process to supply the students’ research activities with the information on engine operation in a variety of ambient and flight conditions during transients. An approach to upgrading the virtual testing rig is proposed. The described modifications would provide the capabilities to solve more complex research tasks, including investigation of influence of geometry of engine elements on the engine characteristics, multidisciplinary investigations, identification of engine models using the results of experimental investigations and identification of sources of engine deficiencies during the development phase of engine designing.


Author(s):  
M. Razi Nalim ◽  
Edwin L. Resler

The wave rotor is a promising means of pressure-gain for gas turbine engines. This paper examines novel wave rotor topping cycles which incorporate low-NOx combustion strategies. This approach combines two-stage ‘rich-quench-lean’ (RQL) combustion with intermediate expansion in the wave rotor to extract energy and reduce the peak stoichiometric temperature substantially. The thermodynamic cycle is a type of reheat cycle, with the rich-zone air undergoing a high pressure stage. Rich-stage combustion could occur external to or within the wave rotor. An approximate analytical design method and CFD/combustion codes are used to develop and simulate wave rotor flow cycles. Engine cycles designed with a bypass turbine and external combustion demonstrate a performance enhancement equivalent to a 200–400°R (110–220°K) increase in turbine inlet temperature. The stoichiometric combustion temperature is reduced by 300–450°R (170–250°K) relative to an equivalent simple cycle, implying substantially reduced NOx formation.


Author(s):  
Matthew J. Driscoll ◽  
Joseph Picozzi

This paper discusses the Unites States Navy’s program to standardize repair and overhaul packages/workscopes for their LM2500 propulsion gas turbine engines. The General Electric LM2500 gas turbine engine is utilized for main propulsion aboard the Navy’s newest surface combatants including the FFG 7, DD 963, CG 47 and DDG 51 class ships. The Navy employs a condition based maintenance philosophy for its fleet of 450 LM2500 engines; removing engines from ships only when in place corrective actions can no longer be effected. Consequently, most LM2500 gas generators and power turbines have exhausted much of their useful life once they arrive at the depot for overhaul. Beginning in 1999, NAVSEA implemented a standardized workscope for these engines to ensure post repair life and performance goals were achieved. This paper discusses the contents of the standardize repair package and the resultant benefits and metrics associated with its execution at both military and commercial facilities.


1996 ◽  
Vol 118 (3) ◽  
pp. 474-480 ◽  
Author(s):  
M. R. Nalim ◽  
E. L. Resler

The wave rotor is a promising means of pressure-gain for gas turbine engines. This paper examines novel wave rotor topping cycles that incorporate low-NOx combustion strategies. This approach combines two-stage “rich-quench-lean” (RQL) combustion with intermediate expansion in the wave rotor to extract energy and reduce the peak stoichiometric temperature substantially. The thermodynamic cycle is a type of reheat cycle, with the rich-zone air undergoing a high-pressure stage. Rich-stage combustion could occur external to or within the wave rotor. An approximate analytical design method and CFD/combustion codes are used to develop and simulate wave rotor flow cycles. Engine cycles designed with a bypass turbine and external combustion demonstrate a performance enhancement equivalent to a 200–400 R (110–220 K) increase in turbine inlet temperature. The stoichiometric combustion temperature is reduced by 300–450 R (170–250 K) relative to an equivalent simple cycle, implying substantially reduced NOx formation.


Author(s):  
Harry Margolis

Compressor waterwashing is a necessary maintenance practice to maintain compressor efficiency for all types of gas turbine engines. This paper discusses U.S. Navy involvement with prototype on-line compressor cleaning systems on marine gas turbine engines. These engines include the General Electric LM2500, the Garrett 831-800, and the Allison 501-K17.


2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110433
Author(s):  
Amin Changizi ◽  
Ion Stiharu ◽  
Bilal Outirba ◽  
Patrick Hendrick

Presented herein is a mathematical model employing differential equations formulation for brush seals used in gas turbine engines. These components are used to seal the bearing chamber from the environment and reduce the loss of lubricant in the atmosphere, ensuring a MTBR long enough to have required the change the seals only during the engine overhaul operation. The model assumes a single curved bristle loop in the form of a curved-bridge beam subjected to the influences of complex external loads (static and dynamic). Further, a model for clustered bristles is proposed. Specifically, the static forces acting on the curved-bridge beam include the weight of the oil capillary attached to the beam, the weight of the beam itself, the capillary force developed between the surfaces of the bristles in the brush and the temperature gradient. The dynamic forces include the leakage oil pressure and the rotation of the shaft. This complex loading induces a nonlinear large deflection on the curved-bridge beam. Also, the temperature gradient present on the bristles during the gas turbine engine operation generates a change in the geometry of the beam and in the magnitude of the forces acting on the bristles modeled as beams. In the present model, the weights are assumed as uniformly distributed forces on the surface of the beam while the capillary forces and the force generated by the rotating shaft are considered to be non-uniform. The equation expressing the curvature of the beam under general loading force is developed and one can choose the appropriate method of solving the generated differential equation after the expression of the general force is defined. Hence, the ordinary differential equation describing the nonlinear large deflection of the curved-bridge beam will be derived using general nonlinear elasticity theory.


Author(s):  
Daniel E. Caguiat ◽  
David M. Zipkin ◽  
Jeffrey S. Patterson

As part of the Gas Turbine Condition Based Maintenance (CBM) Program, Naval Surface Warfare Center, Carderock Division Code 9334 conducted compressor fouling testing on the General Electric LM2500 and Rolls Royce/Allison 501-K Series gas turbines. The objective of these tests was to determine the feasibility of quantifying compressor performance degradation using existing and/or added engine sensors. The end goal of these tests will be to implement an algorithm in the Navy Fleet that will determine the optimum time to detergent crank wash each gas turbine based upon compressor health, fuel economy and other factors which must be determined. Fouling tests were conducted at the Land Based Engineering Site (LBES). For each gas turbine, the test plan that was utilized consisted of injecting a salt solution into the gas turbine inlet, gathering compressor performance and fuel economy data, analyzing the data to verify sensor trends, and assessing the usefulness of each parameter in determining compressor and overall gas turbine health. Based upon data collected during these fouling tests, it seems feasible to accomplish the end goal. Impact Technologies, who analyzed the data sets for both of these fouling tests, has developed a prognostic modeling approach for each of these gas turbines using a combination of the data and probabilistic analysis.


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