Modeling of a Turbofan Engine Start Using a High Fidelity Aero-Thermodynamic Simulation

2012 ◽  
Author(s):  
Igor Fuksman ◽  
Steven Sirica
Keyword(s):  
Thermodynamic Simulation ◽  
Operating Regime ◽  
High Fidelity ◽  
Iterative Solver ◽  
Turbofan Engine ◽  
Conservation Of Energy ◽  
Directional Flow ◽  
Modeling Techniques ◽  
Starting Process ◽  
Engine Start

Simulating the thermodynamics of a multi-spool turbofan engine during engine start can present challenges to the conventional high fidelity aero-thermodynamic simulation. The conventional high fidelity aero-thermodynamic simulation uses an iterative solver technique to preserve flow continuity and conservation of energy based on component maps and subsystem characteristics. Traditionally, operation of such simulations have been limited to regions from self-sustaining idle to maximum power, where component and subsystem representation has been well defined and engine operating pressures are sufficient to ensure one-directional flow. However, simulating transient operation which initiates from engine “off” condition followed by starter engagement and fuel introduction, presents a new set of challenges. These include the modeling of the engine “off” state itself, as well as two aspects of the starting process particular to a multi-spool turbofan: the modeling of the flow passing through the entire core stream even though only the high pressure shaft is rotating, and the modeling of the flow split into the bypass stream when the fan is not rotating. This paper discusses the modeling techniques that have been developed to overcome these challenges in order to ensure the smooth operation starting with engine off and continuing through the regions of starter engagement, fuel addition, and starter disengagement leading to normal engine operating regime.

Real-Time Execution of a High Fidelity Aero-Thermodynamic Turbofan Engine Simulation

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Igor Fuksman ◽  
Steven Sirica
Keyword(s):  
Real Time ◽  
Thermodynamic Simulation ◽  
High Fidelity ◽  
Time Model ◽  
Turbofan Engine ◽  
Engine Simulation ◽  
Thermodynamic Simulations ◽  
Execution Speed ◽  
Asme Turbo Expo ◽  
Function Models

In the past, a typical way of executing simulations in a real-time environment had been to use transfer function models, state-variable models, or reduced-order aero-thermodynamic models. These models are typically not as accurate as the conventional full-fidelity aero-thermodynamic simulations used as a basis for the generation of real-time models. Also, there is a cost associated with the creation and maintenance of these derived real-time models. The ultimate goal is to use the high fidelity aero-thermodynamic simulation as the real-time model. However, execution of the high fidelity aero-thermodynamic simulation in a real-time environment is a challenging objective since accuracy of the simulation cannot be sacrificed to optimize execution speed, yet execution speed still has to be limited by some means to fit into real-time constraint. This paper discusses the methodology used to resolve this challenge, thereby enabling use of a contemporary turbofan engine high fidelity aero-thermodynamic simulation in real-time environments. This publication reflects the work that was initially presented at the ASME Turbo Expo 2011 (Fuksman and Sirica, 2011, “Real-Time Execution of a High Fidelity Aero-Thermodynamic Turbofan Engine Simulation,” ASME Turbo Expo, Jun. 6-10, Vancouver, Canada, Paper No. GT2011-46661).

Real-Time Execution of a High Fidelity Aero-Thermodynamic Turbofan Engine Simulation

2011 ◽  
Author(s):  
Igor Fuksman ◽  
Steven Sirica
Keyword(s):  
Real Time ◽  
Thermodynamic Simulation ◽  
High Fidelity ◽  
Time Model ◽  
Turbofan Engine ◽  
The Real ◽  
Engine Simulation ◽  
Thermodynamic Simulations ◽  
Execution Speed ◽  
Function Models

In the past, a typical way of executing simulations in the real-time environment had been to use transfer function models, state-variable models or reduced-order aero-thermodynamic models. These models are typically not as accurate as the conventional full-fidelity aero-thermodynamic simulations used as basis for generation of the real-time models. Also, there is a cost associated with creation and maintenance of these derived real-time models. The ultimate goal is to use the high fidelity aero-thermodynamic simulation as the real-time model. However, execution of the high fidelity aero-thermodynamic simulation in a real-time environment is a challenging objective since accuracy of the simulation cannot be sacrificed to optimize execution speed, yet execution speed still has to be limited by some means to fit into real-time constraint. This paper discusses the methodology used to resolve this challenge, thereby enabling use of a contemporary turbofan engine high fidelity aero-thermodynamic simulation in the real-time environments.

scholarly journals Optimization for the Starting Process of Turbofan Engine Under High-Altitude Environment

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 55797-55806
Author(s):  
Ma Song ◽  
Tan Jianguo ◽  
Su Sanmai ◽  
Zhu Mingyan
Keyword(s):  
High Altitude ◽  
Turbofan Engine ◽  
Starting Process

Optimal Control of Turbine Engines

1979 ◽  
Vol 101 (2) ◽  
pp. 117-126 ◽  
Author(s):  
R. L. DeHoff ◽  
W. Earl Hall
Keyword(s):  
Optimal Control ◽  
Optimal Design ◽  
Control Design ◽  
Multivariable Control ◽  
Turbine Engines ◽  
Linear Modeling ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Design Procedures ◽  
Modeling Techniques

Multivariable control design for turbine engines has been studied for over 20 years. In the last 10 years, the application of linear, optimal design techniques has produced a number of turbine engine controllers. A group of these design procedures is described and a discussion of the procedures’ performance, complexity and implementation is presented. The design of a full-envelope controller for the F100 turbofan engine based on linear, optimal synthesis and locally linear modeling techniques is discussed. A perspective of optimal control design for turbine engines is presented and the future is examined.

scholarly journals Multi-Fidelity Simulation of a Turbofan Engine With Results Zoomed Into Mini-Maps for a Zero-D Cycle Simulation

2004 ◽  
Author(s):  
Mark G. Turner ◽  
John A. Reed ◽  
Robert Ryder ◽  
Joseph P. Veres
Keyword(s):  
Boundary Conditions ◽  
Fluid Dynamic ◽  
Thermodynamic Cycle ◽  
High Fidelity ◽  
Operating Characteristics ◽  
Cycle Model ◽  
Turbofan Engine ◽  
Engine Model ◽  
Cycle Simulation ◽  
Component Models

A Zero-D cycle simulation of the GE90-94B high bypass turbofan engine has been achieved utilizing mini-maps generated from a high-fidelity simulation. The simulation utilizes the Numerical Propulsion System Simulation (NPSS) thermodynamic cycle modeling system coupled to a high-fidelity full-engine model represented by a set of coupled 3D computational fluid dynamic (CFD) component models. Boundary conditions from the balanced, steady-state cycle model are used to define component boundary conditions in the full-engine model. Operating characteristics of the 3D component models are integrated into the cycle model via partial performance maps generated from the CFD flow solutions using one-dimensional meanline turbomachinery programs. This paper high-lights the generation of the highpressure compressor, booster, and fan partial performance maps, as well as turbine maps for the high pressure and low pressure turbine. These are actually “mini-maps” in the sense that they are developed only for a narrow operating range of the component. Results are compared between actual cycle data at a take-off condition and the comparable condition utilizing these mini-maps. The mini-maps are also presented with comparison to actual component data where possible.

The Modeling and Simulation of Super-Capacitor in Diesel Engine Starting Process

2012 ◽  
Vol 229-231 ◽  
pp. 1967-1970
Author(s):  
Zhen Min Cui ◽  
Ru Wang
Keyword(s):  
Diesel Engine ◽  
System Modeling ◽  
Super Capacitor ◽  
Power Characteristics ◽  
Modeling Simulation ◽  
Auxiliary Power ◽  
Start Up ◽  
Instantaneous Discharge ◽  
Starting Process ◽  
Engine Start

Diesel engine; Super-capacitor; Starter system; Modeling; Simulation Abstract. In order to improve the start-up performance of the diesel engine and the working conditions of batteries, make efficient use of the high instantaneous discharge power characteristics of the super-capacitor as a diesel engine start-up auxiliary power. Taking the YC6J180 types of Yuchai diesel engine as illustration, diesel engine starting process was modeled and simulated by Matlab/Simulink software, and compared with the simulation model of diesel engine starting system added the super-capacitor. The simulation results show that the diesel engine starter system added the super-capacitor as the auxiliary power, the starting performance is improved significantly, meanwhile improve the battery state, and extend its service life.

Comparison of Measured Low-Frequency Engine Noise With Combustion and Jet Noise Predictions for a Turbofan Engine With an Internal Lobed Mixer Nozzle

2007 ◽  
Author(s):  
Lysbeth S. Lieber ◽  
Donald S. Weir
Keyword(s):  
Low Frequency ◽  
Jet Noise ◽  
Combustion Noise ◽  
Noise Model ◽  
Engine Noise ◽  
Turbofan Engine ◽  
Technology Program ◽  
Modeling Techniques ◽  
Noise Data ◽  
Static Conditions

This paper presents an examination of the low-frequency engine noise of a turbofan engine with an internal lobed mixer nozzle, and identifies the contributions of the combustion and exhaust jet component noise sources within the low frequency portion of the spectrum by applying recently developed modeling techniques. This investigation was performed as part of the NASA Quiet Aircraft Technology Program. Because the mixer reduces the total jet noise, the combustion noise source becomes a significant contributor. In addition, the character of the jet noise for the mixer nozzle is different from that for a single-stream or coannular nozzle. Although the internal mixer reduces the low-frequency shear-induced jet noise, it also produces an additional higher frequency contribution to the jet noise due to enhanced turbulence levels produced by the mixing process. Therefore, the modeling techniques that predict the low-frequency component source noise must capture sufficient physics of the noise generation process for the combustor and mixer nozzle to accurately represent the component spectral distributions. The improved modeling of component source noise for both combustor and jet sources was addressed as part of the NASA Quiet Aircraft Technology Program. This activity included development of a new narrowband combustion noise model, as well as the application of a recent jet noise model for nozzles with internal forced mixers. The noise data used in this study was taken during the NASA Engine Validation of Noise Reduction Concepts (EVNRC) Program. Both static and flight noise measurements were made at a range of power settings using the Honeywell TFE731-60 turbofan engine. The engine configuration of interest for this study employed a nozzle with an internal lobed mixer. Comparison of static and flight data with predictions from the combustion and jet noise models indicates that combustor noise has a significant contribution to lower-frequency engine noise (in the 400–1000 Hz range), particularly for flight conditions, where the jet noise is reduced due to flight effects, and also for lower power settings at static conditions. However, further calibration of the combustion and jet noise prediction techniques will be required, with isolated component noise data, before these models may be applied with certainty to model total engine noise in the low-frequency range.

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