Gas Turbine Engine Performance Model Applications Using an Object-Oriented Simulation Tool

2006 ◽  
Author(s):  
A. Alexiou ◽  
K. Mathioudakis
Keyword(s):  
Engine Performance ◽  
Object Oriented ◽  
Performance Model ◽  
Simulation Tool ◽  
Performance Models ◽  
External Application ◽  
Turbine Engine ◽  
Engine Model ◽  
Turbine Component ◽  
Engine Components

Engine performance models are used throughout the life cycle of an engine from conceptual design to testing, certification and maintenance. The objective of this paper is to demonstrate the use and advantages of an engine performance model, developed using an object-oriented simulation tool, for the following applications: • Building an engine model from existing engine components and running steady state and transient calculations. • Development and integration of a new cooled turbine component in the existing engine model. • Accessing the engine model from an external application. • Using an external legacy routine in the engine model.

Secondary Air System Component Modelling for Engine Performance Simulations

2008 ◽  
Author(s):  
A. Alexiou ◽  
K. Mathioudakis
Keyword(s):  
Experimental Data ◽  
Engine Performance ◽  
Object Oriented ◽  
System Component ◽  
Computational Results ◽  
Simulation Environment ◽  
Performance Models ◽  
Engine Model ◽  
Air System ◽  
Secondary Air

This paper describes the modelling of typical secondary air system elements such as rotating orifices, seals and flow passages with heat and work transfer from the surrounding surfaces. The modelling is carried out in an object-oriented simulation environment that allows the creation of different configurations in a simple and flexible manner. This makes possible to compare the performance between different designs of individual components or complete secondary air systems as well as integrate them directly in whole engine performance models. The modelling is validated against published experimental data and computational results. An example of implementation in an engine model is also presented.

Secondary Air System Component Modeling for Engine Performance Simulations

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
A. Alexiou ◽  
K. Mathioudakis
Keyword(s):  
Experimental Data ◽  
Engine Performance ◽  
Object Oriented ◽  
System Component ◽  
Computational Results ◽  
Simulation Environment ◽  
Performance Models ◽  
Engine Model ◽  
Air System ◽  
Secondary Air

This paper describes the modeling of typical secondary air system elements such as rotating orifices, seals, and flow passages with heat and work transfer from the surrounding surfaces. The modeling is carried out in an object-oriented simulation environment that allows the creation of different configurations in a simple and flexible manner. This makes possible to compare the performance between different designs of individual components or complete secondary air systems as well as integrate them directly in whole engine performance models. The modeling is validated against published experimental data and computational results. An example of implementation in an engine model is also presented.

Effect of Manufacturing Variability on Turbine Engine Performance: A Probabilistic Study

2013 ◽  
Author(s):  
Michael Gorelik ◽  
Jacob Obayomi ◽  
Jack Slovisky ◽  
Dan Frias ◽  
Howie Swanson ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Model Development ◽  
Engine Performance ◽  
Performance Model ◽  
Probabilistic Methods ◽  
System Level ◽  
Turbine Engine ◽  
Probabilistic Study ◽  
Blade Geometry

While turbine engine Original Equipment Manufacturers (OEMs) accumulated significant experience in the application of probabilistic methods (PM) and uncertainty quantification (UQ) methods to specific technical disciplines and engine components, experience with system-level PM applications has been limited. To demonstrate the feasibility and benefits of an integrated PM-based system, a numerical case study has been developed around the Honeywell turbine engine application. The case study uses experimental observations of engine performance such as horsepower and fuel flow from a population of engines. Due to manufacturing variability, there are unit-to-unit and supplier-to-supplier variations in compressor blade geometry. Blade inspection data are available for the characterization of these geometric variations, and CFD analysis can be linked to the engine performance model, so that the effect of blade geometry variation on system-level performance characteristics can be quantified. Other elements of the case study included the use of engine performance and blade geometry data to perform Bayesian updating of the model inputs, such as efficiency adders and turbine tip clearances. A probabilistic engine performance model was developed, system-level sensitivity analysis performed, and the predicted distribution of engine performance metrics was calibrated against the observed distributions. This paper describes the model development approach and key simulation results. The benefits of using PM and UQ methods in the system-level framework are discussed. This case study was developed under Defense Advanced Research Projects Agency (DARPA) funding which is gratefully acknowledged.

Development and Integration of Rain Ingestion Effects in Engine Performance Simulations

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
I. Roumeliotis ◽  
A. Alexiou ◽  
N. Aretakis ◽  
G. Sieros ◽  
K. Mathioudakis
Keyword(s):  
Engine Performance ◽  
Velocity Slip ◽  
Droplet Surface ◽  
Performance Model ◽  
Droplet Breakup ◽  
Test Case ◽  
Case Scenario ◽  
Worst Case ◽  
Engine Model ◽  
Component Models

Rain ingestion can significantly affect the performance and operability of gas turbine aero-engines. In order to study and understand rain ingestion phenomena at engine level, a performance model is required that integrates component models capable of simulating the physics of rain ingestion. The current work provides, for the first time in the open literature, information about the setup of a mixed-fidelity engine model suitable for rain ingestion simulation and corresponding overall engine performance results. Such a model can initially support an analysis of rain ingestion during the predesign phase of engine development. Once components and engine models are validated and calibrated versus experimental data, they can then be used to support certification tests, the extrapolation of ground test results to altitude conditions, the evaluation of control or engine hardware improvements and eventually the investigation of in-flight events. In the present paper, component models of various levels of fidelity are first described. These models account for the scoop effect at engine inlet, the fan effect and the effects of water presence in the operation and performance of the compressors and the combustor. Phenomena such as velocity slip between the liquid and gaseous phases, droplet breakup, droplet–surface interaction, droplet and film evaporation as well as compressor stages rematching due to evaporation are included in the calculations. Water ingestion influences the operation of the components and their matching, so in order to simulate rain ingestion at engine level, a suitable multifidelity engine model has been developed in the Proosis simulation platform. The engine model's architecture is discussed, and a generic high bypass turbofan is selected as a demonstration test case engine. The analysis of rain ingestion effects on engine performance and operability is performed for the worst case scenario, with respect to the water quantity entering the engine. The results indicate that rain ingestion has a strong negative effect on high-pressure compressor surge margin, fuel consumption, and combustor efficiency, while more than half of the water entering the core is expected to remain unevaporated and reach the combustor in the form of film.

Validation of a Mixed Flow Turbofan Performance Model in the Sub-Idle Operating Range

2003 ◽  
Author(s):  
Claus Riegler ◽  
Michael Bauer ◽  
Holger Schulte
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Performance Model ◽  
Maximum Power ◽  
Development Programs ◽  
Mixed Flow ◽  
Typical Application ◽  
Operating Range ◽  
Engine Model ◽  
Lighting Conditions

During turbofan development programs the evaluation of steady-state and transient engine performance is usually achieved by applying full thermodynamic engine models at least in the operating range between idle and maximum power conditions, but more recently also in the sub-idle operating range, e.g. for steady-state windmilling behavior and for starting, relight and shut down scenarios. The paper describes the setup, and in more detail the validation, of a full thermodynamic engine model for a two-spool mixed flow afterburner turbofan which is capable to run from maximum power down to zero speed and zero flow conditions in steady-state and transient mode. The validation is performed by using the model-based performance analysis procedure called ANSYN even in windmilling operation. Once the steady-state sub-idle model is validated the extension to transient sub-idle capability is achieved by simply adding the effects of rotor moment of inertia of the spools, while heat soakage effects are rather negligible without heat release in the burner. Especially lighting conditions in the burner are produced by such a validated sub-idle model inherently due to reliable data calculated at the burner entry station. The variety of applications of a validated full thermodynamic engine model is large. The performance data delivered is highly reliable and very consistent because the full operating range of the engine is covered with one model, and by appropriate means of speeding up the calculation even real-time capability may be achieved. In the paper synthesized data for an engine dry crank is compared to real engine test data as one typical application.

Compressor Characteristics in Gas Turbine Performance Modelling

2001 ◽  
Author(s):  
Geoff Jones ◽  
Pericles Pilidis ◽  
Barry Curnock
Keyword(s):  
Gas Turbine ◽  
Pressure Loss ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Performance Model ◽  
Flow Function ◽  
Performance Modelling ◽  
Turbine Engine ◽  
Loss Parameter ◽  
Modelling Methods

The choice of how to represent the performance of the fans and compressors of a gas turbine engine in a whole-engine performance model can be critical to the number of iterations required by the solver or indeed whether the system can be solved. This paper therefore investigates a number of compressor modelling methods and compares their relative merits. Particular attention is given to investigating the ability of the various representations to model the performance far from design point. It is noted that, for low rotational speeds and flows, matching on pressure ratio will produce problems, and that efficiency is a discontinuous function at these conditions. Thus, such traditional representations of compressors are not suitable for investigations of starting or windmilling performance. Matching on pressure ratio, Beta, the Crainic exit flow function and the true exit flow function is investigated. The independent parameters of isentropic efficiency, pressure loss, a modified pressure loss parameter, specific torque, and ideal and actual enthalpy rises are compared. The requirements of the characteristic choice are investigated, with regard to choosing matching variables and ensuring that relationships are smooth and continuous throughout the operating range of the engine.

Thrust Reverser for a Separate Exhaust High Bypass Ratio Turbofan Engine and its Effect on Aircraft and Engine Performance

2011 ◽  
Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Vishal Sethi ◽  
Pericles Pilidis
Keyword(s):  
Engine Performance ◽  
Aircraft Engine ◽  
Performance Characteristics ◽  
System Level ◽  
Performance Models ◽  
Turbofan Engine ◽  
Engine Model ◽  
Rate Deceleration ◽  
Thrust Reverser ◽  
Bypass Ratio

This paper discusses thrust reversing techniques for a separate exhaust high bypass ratio turbofan engine and its effect on aircraft and engine performance. Cranfield University is developing suitable thrust reverser performance models. These thrust reverser performance models will subsequently be integrated within the TERA (Techno-economic Environmental Risk Analysis) architecture thereby allowing for more detailed and accurate representations of aircraft and engine performance during the landing phase of a typical civil aircraft mission. The turbofan engine chosen for this study was CUTS_TF (Cranfield University Twin Spool Turbofan) which is similar to the CFM56-5B4 engine and the information available in the public domain is used for the engine performance analysis along with the Gas Turbine Performance Software, ‘GasTurb 10’ [1]. The CUTEA (Cranfield University Twin Engine Aircraft) which is similar to the Airbus A320 is used alongside with the engine model for the thrust reverser performance calculations. The aim of this research paper is to investigate the effects on aircraft and engine performance characteristics due to the pivoting door type thrust reverser deployment. The paper will look into the overall engine performance characteristics and how the engine components get affected when the thrust reversers come into operation. This includes the changes into the operating point of fan, booster, HP compressor, HP turbine, LP turbine, bypass nozzle and core nozzle. Also, thrust reverser performance analyses were performed (at aircraft/engine system level) by varying the reverser exit area by ± 5% and its effect on aircraft deceleration rate, deceleration time and landing distances were observed.

Thrust Reverser for a Mixed Exhaust High Bypass Ratio Turbofan Engine and its Effect on Aircraft and Engine Performance

2012 ◽  
Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Syed H. Rizvi ◽  
Pericles Pilidis ◽  
Mark Savill ◽  
...  
Keyword(s):  
Engine Performance ◽  
Engine Exhaust ◽  
Turbofan Engine ◽  
The Public ◽  
Engine Model ◽  
Turbine Performance ◽  
Lp Turbine ◽  
Engine Components ◽  
Thrust Reverser ◽  
Bypass Ratio

This paper discusses thrust reverser techniques for a mixed exhaust high bypass ratio turbofan engine and its effect on aircraft and engine performance. The turbofan engine chosen for this study was CUTS_TF (Cranfield University Three Spool Turbofan) which is similar to Rolls-Royce TRENT 772 engine and the information available for this engine in the public domain is used for the engine performance analysis along with the Gas Turbine Performance Software, GasTurb 10. The CUTEA (Cranfield University Twin Engine Aircraft) which is similar to the Airbus A330 is used along side with the engine model for the thrust reverser performance calculations. The aim of this research paper is to investigate the effects on mixed exhaust engine performance due to the pivoting door type thrust reverser deployment. The paper looks into the engine off-design performance characteristics and how the engine components get affected when the thrust reverser come into operation. This includes the changes into the operating point of fan, IP compressor, HP compressor, HP turbine, IP turbine, LP turbine and the engine exhaust nozzle. Also, the reverser deployment effect on aircraft, deceleration time and landing distances are discussed.

GSP, a Generic Object-Oriented Gas Turbine Simulation Environment

2000 ◽  
Author(s):  
Wilfried P. J. Visser ◽  
Michael J. Broomhead
Keyword(s):  
Performance Analysis ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Object Oriented ◽  
Control Logic ◽  
Turbine Engine ◽  
Industrial Gas Turbines ◽  
On Line ◽  
Turboshaft Engine

NLR’s primary tool for gas turbine engine performance analysis is the ‘Gas turbine Simulation Program’ (GSP), a component based modeling environment. GSP’s flexible object-oriented architecture allows steady-state and transient simulation of any gas turbine configuration using a user-friendly drag&drop interface with on-line help running under Windows95/98/NT. GSP has been used for a variety of applications such as various types of off-design performance analysis, emission calculations, control system design and diagnostics of both aircraft and industrial gas turbines. More advanced applications include analysis of recuperated turboshaft engine performance, lift-fan STOVL propulsion systems, control logic validation and analysis of thermal load calculation for hot section life consumption modeling. In this paper the GSP modeling system and object-oriented architecture are described. Examples of applications for both aircraft and industrial gas turbine performance analysis are presented.

scholarly journals An Object-Oriented Approach to Gas Turbine Performance Computation

1996 ◽  
Author(s):  
Peng Yip Ho ◽  
Poh Seng Ng
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Object Oriented ◽  
Object Oriented Programming ◽  
Data Types ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Source Codes ◽  
Flexible Designs ◽  
Amount Of Knowledge

This paper aims to introduce Object-Oriented Programming (OOP) concepts in the context of gas turbine engine performance computations. Objects are collections of data and functions that represents useful elements in an application. They are a means of extending the standard programming language to endow it with data types that are natural metaphors for both physical objects and abstract entities within the application program. Objects are valuable in designing and implementing software because they hide complexity, reducing the amount of knowledge required about any objects in order to use it. These properties also allow objects to be modified or replaced without affecting other areas of the application. Thus, this results in flexible designs and increased productivity by providing reusable software without sacrificing flexibility. The fundamental OOP concepts such as encapsulation, inheritance, and polymorphism are explained and exemplified by source codes from a turbofan engine performance computation software. The advantages of these over traditional programming paradigms are highlighted. The resulting program source code is readable, self-documenting, robust, and highly modular. Furthermore, the software for a turbofan engine is essentially a collection of objects that forms the basic framework for modelling all conceivable forms of gas turbine engines.

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