scholarly journals Advanced Control Considerations for Turbofan Engine Design

2016 ◽  
Author(s):  
Joseph W. Connolly ◽  
Jeffrey Csank ◽  
Amy Chicatelli
Keyword(s):  
Turbofan Engine ◽  
Engine Design ◽  
Advanced Control

Exploring GasTurb 12 for Supplementary Use on an Introductory Propulsion Design Project

2017 ◽  
Author(s):  
Aaron R. Byerley ◽  
Kurt P. Rouser ◽  
Devin O. O’Dowd
Keyword(s):  
System Analysis ◽  
Pressure Ratio ◽  
Supplementary Information ◽  
Design System ◽  
Inlet Temperature ◽  
Turbofan Engine ◽  
Design Project ◽  
Engine Design ◽  
Aeronautical Engineering ◽  
Engine Cycle

The purpose of this paper is to explore GasTurb 12, a commercial gas turbine engine performance simulation program, for supplementary use on an introductory propulsion design project in an undergraduate course. This paper will describe several possible opportunities for supplementing AEDsys (Aircraft Engine Design System Analysis) version 4.012, the engine design software tool currently in use. The project is assigned to juniors taking their first propulsion course in the aeronautical engineering major at the USAF Academy. This course, Aeronautical Engineering 361, which focuses on cycle analysis and selection, is required of all aero majors and is used to satisfy the ABET Program Criterion requiring knowledge of propulsion fundamentals. This paper describes the most recent design project that required the students to re-engine the USAF T-38 with the aim of competing for the Advanced Pilot Training Program (T-X) program. The goal of the T-X program is to replace the T-38 aircraft that entered service in 1961 with an aircraft capable of sustained high-G operations that is also more fuel efficient. The design project required the students to select an engine-cycle for a single, non-afterburning, mixed stream, low bypass turbofan engine to replace the two J85 turbojets currently in the T-38. It was anticipated that the high specific thrust requirements might possibly be met through the use of modern component measures of merit to include a much higher turbine inlet temperature. Additionally, it was anticipated that the required 10% reduction in thrust specific fuel consumption might possibly be achieved by using a turbofan engine cycle with a higher overall pressure ratio. This paper will describe the use of GasTurb 12 to perform the same design analysis that was described above using AEDsys as well as additional features such as numerical optimization, temperature-entropy diagrams, and the generation of scaled, two-dimensional engine geometry drawings. The paper will illustrate how GasTurb 12 offers important supplementary information that will deepen student understanding of engine cycle design and analysis.

Optimization of Turbofan Engine Design Point by using Seven Level Orthogonal Array

2013 ◽  
Vol 17 (4) ◽  
pp. 10-15
Author(s):  
Myungho Kim ◽  
Youil Kim ◽  
Kwangki Lee ◽  
Kiyoung Hwang ◽  
Seongki Min
Keyword(s):  
Orthogonal Array ◽  
Turbofan Engine ◽  
Design Point ◽  
Engine Design

scholarly journals An Advanced Control System for Turbofan Engine: Multivariable Control and Fuzzy Logic (Application to the M88-2 Engine)

1995 ◽  
Author(s):  
Alain Garassino
Keyword(s):  
Fuzzy Logic ◽  
Control Systems ◽  
Performance Index ◽  
Multivariable Control ◽  
Outer Loop ◽  
Turbofan Engine ◽  
Stall Margin ◽  
Control Loops ◽  
Advanced Control ◽  
Fuzzy Supervisor

The search for better performance of present and future turbofan engine involves an increase on the number of variable geometries and thus of control loops. As we can not or do not want to disregard the interaction between loops any more, the future control systems will therefore be multivariable. The aim of the architecture of multivariable control presented here is to optimize a performance index during transients. This architecture consists of an inner loop which optimizes the performance index taking in account the limitations, an outer loop which brings the nominal steady-state offsets to zero and a trajectory which allows to take into account the topping schedule limitation. This basic architecture can be improved by fuzzy supervisor. Indeed, two control outputs are generated according to the description above: - the first one optimizes the thrust and does not care very much about LP stall margin limitation, - the second one optimizes again the thrust and strongly takes low pressure stall margin limitation into account. The fuzzy logic then allows to do a compromise between these two control outputs according to the engine state. Simulation results showing the efficiency of the method are given.

Parametric Study for Adoption of Variable Cycle Engine Concept for Low Bypass Ratio Turbofan Engine

2019 ◽  
Author(s):  
Kaviya Swaminathan ◽  
Chetan S. Mistry
Keyword(s):  
Fuel Consumption ◽  
Mass Flow ◽  
Parametric Study ◽  
High Efficiency ◽  
Turbofan Engine ◽  
Engine Design ◽  
Flow Through ◽  
Operating Points ◽  
Bypass Ratio ◽  
Multiple Operating Points

Abstract Turbojet and turbofan engine propulsion system are extensively used in aircraft. Turbojets have simple engine design and extensively used for supersonic flights. Turbofan engine has high mass flow rate and efficient for subsonic application. Variable Cycle Engines, unlike the traditional engines, can vary between high thrust mode for supersonic operations and high efficiency mode for subsonic operations hence are potentially attractive for supersonic transport and advanced tactical fighter aircraft. Variable Cycle Engine can be described as the one that operates with two or more cycles, could serve as a possible solution to reconciling the necessary performance at different operating conditions. The aim of the engine is to combine the best traits of turbojet (high specific thrust) and turbofan (low specific fuel consumption, low noise). Traditional engines have fixed mass flow but VCE can alter the mass flow and function as high bypass engine for the subsonic case and low bypass engine at the supersonic case. Different variable cycle engine design philosophies were studied and the engine architecture used in F120 was incorporated into the base design of a low bypass ratio Turbofan Engine. Cycle analysis of VCE was primarily done based on theoretical calculation and parametric study performed with the use of Gasturb software. Two Variable Area Bypass Injectors (VABI) were used to vary the mass flow through the core and the bypass stream. We aspire to achieve enhanced performance at subsonic and supersonic mission segments. Subsonic, supersonic and take off conditions were decided and the base engine was modified to have multiple operating points. The VCE combines two cycles (subsonic, supersonic) in same engine body and it is crucial for the engine components to deliver the required performance at both the design points. The engine design procedure consists of the matching of components like turbine, compressor, exhaust nozzle and the exhaust mixing area. Systematic study of turbine matching for such engine configuration with multiple operating points was carried out to understand the utility of variable geometry in a VCE. For turbine matching, the mass flow through turbine was held constant by adjusting the VABIs and this was repeated for different takeoff conditions to analyses the output in detail. The non dimensional mass flow through the turbine was fixed for both the design points and hence the turbine could be designed to provide high efficiency. The fuel consumption was found to have decreased compared to the baseline condition which in turn leads to low SFC and higher endurance.

System Identification of Jet Engines

1999 ◽  
Vol 122 (1) ◽  
pp. 19-26 ◽  
Author(s):  
N. Sugiyama
Keyword(s):  
System Identification ◽  
Jet Engines ◽  
Turbofan Engine ◽  
Jet Engine ◽  
Performance Change ◽  
Electric Control ◽  
Advanced Control ◽  
Identification Technique ◽  
Using Data ◽  
Engine Components

System identification plays an important role in advanced control systems for jet engines, in which controls are performed adaptively using data from the actual engine and the identified engine. An identification technique for jet engine using the Constant Gain Extended Kalman Filter (CGEKF) is described. The filter is constructed for a two-spool turbofan engine. The CGEKF filter developed here can recognize parameter change in engine components and estimate unmeasurable variables over whole flight conditions. These capabilities are useful for an advanced Full Authority Digital Electric Control (FADEC). Effects of measurement noise and bias, effects of operating point and unpredicted performance change are discussed. Some experimental results using the actual engine are shown to evaluate the effectiveness of CGEKF filter. [S0742-4795(00)00401-4]

Off-Design Performance of an Interstage Turbine Burner Turbofan Engine

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Feijia Yin ◽  
Arvind G. Rao
Keyword(s):  
Fuel Efficiency ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Engine Operation ◽  
Turbofan Engine ◽  
Design Performance ◽  
Low Pressure Turbine ◽  
Performance Requirements ◽  
Engine Design ◽  
Operating Points

This paper focuses on the off-design performance of a turbofan engine with an interstage turbine burner (ITB). The ITB is an additional combustion chamber located between the high-pressure turbine (HPT) and the low-pressure turbine (LPT). The incorporation of ITB in an engine can provide several advantages, especially due to the reduction in the HPT inlet temperature and the associated NOx emission reduction. The objective is to evaluate the effects of the ITB on the off-design performance of a turbofan engine. The baseline engine is a contemporary classical turbofan. The effects of the ITB are evaluated on two aspects: first, the influences of an ITB on the engine cycle performance; second, the influences of an ITB on the component characteristics. The dual combustors of an ITB engine provide an extra degree-of-freedom for the engine operation. The analysis shows that a conventional engine has to be oversized to satisfy off-design performance requirement, like the flat rating temperature. However, the application of an ITB eases the restrictions imposed by the off-design performance requirements on the engine design, implying that the off-design performance of an ITB engine can be satisfied without sacrificing the fuel efficiency. Eventually, the performance of the ITB engine exhibits superior characteristics over the baseline engine at the studied operating points over a flight mission.

scholarly journals Rapid Calculation of Engine Performance

1985 ◽  
Author(s):  
Zhang Jin ◽  
Zhu Xinjian
Keyword(s):  
Working Conditions ◽  
Statistical Data ◽  
Engine Performance ◽  
Calculation Procedure ◽  
Turbofan Engine ◽  
Design Performance ◽  
Engine Design ◽  
Rapid Calculation ◽  
Performance Calculation ◽  
Preliminary Phase

A rapid calculation procedure for design and off-design performance of turbojet and turbofan engine is developed. It peculiarity is that the general characteristics of components are established based on statistical data and the engine working conditions are searched according to matching of these general characteristics. This method can be used to select cycle parameters in engine design, and has been employed in engine performance calculation program used in the preliminary phase of engine design or airframe/engine integration design.

scholarly journals System Identification of Jet Engines

1998 ◽  
Author(s):  
Nanahisa Sugiyama
Keyword(s):  
System Identification ◽  
Jet Engines ◽  
Turbofan Engine ◽  
Jet Engine ◽  
Performance Change ◽  
Electric Control ◽  
Advanced Control ◽  
Identification Technique ◽  
Using Data ◽  
Engine Components

System identification plays an important role in advanced control systems for jet engines, in which controls are performed adaptively using data from the actual engine and the identified engine. An identification technique for jet engine using the Constant Gain Extended Kalman Filter (CGEKF) is described. The filter is constructed for a two-spool turbofan engine. The CGEKF filter developed here can recognize parameter change in engine components and estimate unmeasurable variables over whole flight conditions. These capabilities are useful for an advanced Full Authority Digital Electric Control (FADEC). Effects of measurement noise and bias, effects of operating point and unpredicted performance change are discussed. Some experimental results using the actual engine are shown to evaluate the effectiveness of CGEKF filter.

Advanced Control for Constrained Processes and Systems

2011 ◽  
Author(s):  
Fabricio Garelli ◽  
Ricardo J. Mantz ◽  
Hernán De Battista
Keyword(s):  
Advanced Control
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