Real-Time Burst Signal Removal Using Multicolor Pyrometry Based Filter for Improved Jet Engine Control

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Guanghua Wang ◽  
Jordi Estevadeordal ◽  
Nirm Nirmalan ◽  
Sean P. Harper
Keyword(s):  
Real Time ◽  
Operating Conditions ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Root Cause ◽  
Control Functions ◽  
Wide Range ◽  
Voltage Signal ◽  
And Control

Online line-of-sight (LOS) pyrometer is used on certain jet engines for diagnosis and control functions such as hot-blade detection, high-temperature limiting, and condition-based monitoring. Hot particulate bursts generated from jet engine combustor at certain running conditions lead to intermittent high-voltage signal outputs from the LOS pyrometer which is ultimately used by the onboard digital engine controller (DEC). To study the nature of hot particulates and enable LOS pyrometer functioning under burst conditions, a multicolor pyrometry (MCP) system was developed under DARPA funded program and tested on an aircraft jet engine. Soot particles generated as byproduct of combustion under certain conditions was identified as the root cause for the signal burst in a previous study. The apparent emissivity was then used to remove burst signals. In current study, the physics based filter with MCP algorithm using apparent emissivity was further extended to real-time engine control by removing burst signals at real time (1 MHz) and at engine DEC data rate. Simulink models are used to simulate the performances of the filter designs under engine normal and burst conditions. The results are compared with current LOS pyrometer results and show great advantage. The proposed model enables new LOS pyrometer design for improved engine control over wide range of operating conditions.

Real-Time Burst Signal Removal Using Multi-Color Pyrometry Based Filter for Improved Jet Engine Control

2014 ◽  
Author(s):  
Guanghua Wang ◽  
Jordi Estevadeordal ◽  
Sean P. Harper ◽  
Nirm Nirmalan
Keyword(s):  
Real Time ◽  
Operating Conditions ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Root Cause ◽  
Control Functions ◽  
Wide Range ◽  
Voltage Signal ◽  
And Control

Online line-of-sight (LOS) pyrometer is used on certain jet engines for diagnosis and control functions such as hot-blade detection, high-temperature limiting, and condition-based monitoring. Hot particulate bursts generated from jet engine combustor at certain running conditions lead to intermittent high-voltage signal outputs from the LOS pyrometer which is ultimately used by the onboard Digital Engine Controller (DEC). To study the nature of hot particulates and enable LOS pyrometer functioning under burst conditions, a Multi-Color Pyrometry (MCP) system was developed under DARPA funded program and tested on an aircraft jet engine. Soot particles generated as by-product of combustion under certain conditions was identified as the root cause for the signal burst in a previous study. The apparent emissivity was then used to remove burst signals. In current study, the physics based filter with MCP algorithm using apparent emissivity was further extended to real-time engine control by removing burst signals at real time (1MHz) and at engine DEC data rate. Simulink models are used to simulate the performances of the filter designs under engine normal and burst conditions. The results are compared with current LOS pyrometer results and show great advantage. The proposed model enables new LOS pyrometer design for improved engine control over wide range of operating conditions.

Design and Analysis of an Intentional Mistuning Experiment Reducing Flutter Susceptibility and Minimizing Forced Response of a Jet Engine Fan

2017 ◽  
Author(s):  
Felix Figaschewsky ◽  
Arnold Kühhorn ◽  
Bernd Beirow ◽  
Jens Nipkau ◽  
Thomas Giersch ◽  
...  
Keyword(s):  
Computational Model ◽  
Paint Layer ◽  
Forced Vibrations ◽  
Forced Response ◽  
Operating Conditions ◽  
Jet Engines ◽  
Jet Engine ◽  
Aspect Ratios ◽  
Engine Order ◽  
Stall Flutter

Recent demands for a reduction of specific fuel consumption of jet engines have been opposed by increasing propulsive efficiency with higher bypass ratios and increased engine sizes. At the same time the challenge for the engine development is to design safe and efficient fan blades of high aspect ratios. Since the fan is the very first rotor stage, it experiences significant distortions in the incoming flow depending on the operating conditions. Flow distortions do not only lead to a performance and stall margin loss but also to remarkable low engine order (LEO) excitation responsible for forced vibrations of fundamental modes. Additionally, fans of jet engines typically suffer from stall flutter, which can be additionally amplified by reflections of acoustic pressure waves at the intake. Stall flutter appears before approaching the stall line on the fan’s characteristic and limits its stable operating range. Despite the fact that this “flutter bite” usually affects only a very narrow speed range, it reduces the overall margin of safe operation significantly. With increasing aspect ratios of ultra-high bypass ratio jet engines the flutter susceptibility will probably increase further and emphasizes the importance of considering aeromechanical analyses early in the design phase of future fans. This paper aims at proving that intentional mistuning is able to remove the flutter bite of modern jet engine fans without raising issues due to heavily increased forced vibrations induced by LEO excitation. Whereas intentional mistuning is an established technology in mitigating flutter, it is also known to amplify the forced response. However, recent investigations considering aeroelastic coupling revealed that under specific circumstances mistuning can also reduce the forced response due to engine order excitation. In order to allow a direct comparison and to limit costs as well as effort at the same time, the intentional mistuning is introduced in a non-destructive way by applying heavy paint to the blades. Its impact on the blade’s natural frequencies is estimated via finite element models with an additional paint layer. In parallel, this procedure is experimentally verified with painted fan blades in the laboratory. A validated SNM (subset of nominal system modes) representation of the fan is used as a computational model to characterize its mistuned vibration behavior. Its validation is done by comparing mistuned mode shape envelopes and frequencies of an experimental modal analysis at rest with those obtained by the updated computational model. In order to find a mistuning pattern minimizing the forced response of mode 1 and 2 at the same time and satisfying stability and imbalance constraints, a multi-objective optimization has been carried out. Finally, the beneficial properties of the optimized mistuning pattern are verified in a rig test of the painted rotor.

scholarly journals Designing Stipulated Gains of Aircraft Stability and Control Augmentation Systems for Semiglobal Trajectories Tracking

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Mostafa Y. B. Elshabasy ◽  
Yongki Yoon ◽  
Ashraf Omran
Keyword(s):  
Control Method ◽  
Simple Procedure ◽  
Operating Conditions ◽  
Stability And Control ◽  
Wide Range ◽  
Flight Envelope ◽  
The Stability ◽  
Classical Control ◽  
And Control ◽  
Aircraft Stability And Control

The main objective of the current investigation is to provide a simple procedure to select the controller gains for an aircraft with a largely wide complex flight envelope with different source of nonlinearities. The stability and control gains are optimally devised using genetic algorithm. Thus, the gains are tuned based on the information of a single designed mission. This mission is assigned to cover a wide range of the aircraft’s flight envelope. For more validation, the resultant controller gains were tested for many off-designed missions and different operating conditions such as mass and aerodynamic variations. The results show the capability of the proposed procedure to design a semiglobal robust stability and control augmentation system for a highly maneuverable aircraft such as F-16. Unlike the gain scheduling and other control design methodologies, the proposed technique provides a semi-global single set of gains for both aircraft stability and control augmentation systems. This reduces the implementation efforts. The proposed methodology is superior to the classical control method which rigorously requires the linearization of the nonlinear aircraft model of the investigated highly maneuverable aircraft and eliminating the sources of nonlinearities mentioned above.

scholarly journals GE ENERGY Jenbacher gas engine technology – preventive maintenance by means of highly sophisticated control systems

2006 ◽  
Vol 125 (2) ◽  
pp. 82-86
Author(s):  
Thomas ELSENBRUCH
Keyword(s):  
Control Systems ◽  
Data Transmission ◽  
Operating Conditions ◽  
Engine Operation ◽  
Actual Operating ◽  
Wide Range ◽  
Control Concept ◽  
On Line ◽  
Optimal Adjustment ◽  
And Control

Data collection and control concept of Jenbacher gas engines has been presented in the paper. Internet data transmission allow on-line control of the engine operation, early detection of defects and optimal adjustment to engine actual operating conditions. The system offers both customers and GE Jenbacher maintenance staff a wide range of functionalities for commissioning, monitoring and maintaining installations and for diagnostic purposes.

A Novel Mini Jet Engine Powered Unmanned Aerial Vehicle: Modeling and Control

2021 ◽  
pp. 1-13
Author(s):  
Erdinç Altuğ ◽  
Abdullah Türkmen
Keyword(s):  
Jet Engines ◽  
Flight Duration ◽  
Thrust Vectoring ◽  
Jet Engine ◽  
Modeling And Control ◽  
Engine Thrust ◽  
Heavy Lift ◽  
Aerial Vehicle ◽  
Thrust System ◽  
And Control

Significant progress has been made in recent years on personal air vehicles (PAVs), which offer independent and autonomous urban transportation. On-demand parcel delivery drones and heavy-lift drones are gaining serious attention. Although various designs for these systems have been put forward, they still have not reached sufficient maturity. The current systems provide somehow satisfactory operation, but many of these systems are limited in payload capacity and flight duration, and not suitable for future operations. In this paper, we propose a novel thrust system that uses multiple mini jet engines. Unlike electric motors, the jet engine thrust cannot vary rapidly. This led us to design and develop a thrust vectoring system for each jet engine. This proposed system has the potential to enable drones to carry more payload and achieve longer flight times. This paper discusses the design and modeling of the system as well as the stabilization algorithms that satisfactorily stabilize the proposed system. We presented that due to motor lag, thrust variations cannot stabilize the vehicle. We showed that the use of a thrust vectoring mechanism with LQR-based controller can overcome the effects of motor lag and stabilize the vehicle, successfully.

Multicolor Techniques for Identification and Filtering of Burst Signals in Jet Engine Pyrometers

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Jordi Estevadeordal ◽  
Guanghua Wang ◽  
Nirm Nirmalan ◽  
Anquan Wang ◽  
Sean P. Harper ◽  
...  
Keyword(s):  
High Speed ◽  
Aircraft Engine ◽  
Line Of Sight ◽  
Research Projects ◽  
Jet Engine ◽  
Root Cause ◽  
Voltage Signal ◽  
Signal Output ◽  
Simulation Results ◽  
Radiant Temperature

A Defense Advanced Research Projects Agency (DARPA)-funded multicolor pyrometry (MCP) experiment was carried out on a government-provided aircraft engine to study the nature of hot particulate bursts generated from the combustor at certain engine conditions. These bursts of hot particulates lead to intermittent high-voltage signal output from the line-of-sight (LOS) pyrometer that is ultimately detected and used by the onboard digital engine controller (DEC). The investigation used a high-speed MCP system designed to detect bursts and identify their properties. Results of the radiant temperature, multicolor temperature, and apparent emissivity are presented. The results indicated that the apparent emissivity calculated during the signal burst was lower than that of the blade. The root cause for the signal burst was identified as soot particles generated as a by-product of combustion under certain conditions. This conclusion was drawn based on both experimental and simulation results. Technical strategies to separate, reduce, or remove the burst signal are proposed.

Dynamic digital image analysis: emerging technology for particle characterization

2004 ◽  
Vol 50 (12) ◽  
pp. 19-26 ◽  
Author(s):  
G. Rabinski ◽  
D. Thomas
Keyword(s):  
Real Time ◽  
Digital Image Analysis ◽  
Visual Analysis ◽  
Dynamic Imaging ◽  
Operating Conditions ◽  
Particle Sizes ◽  
Particle Characterization ◽  
Imaging Analysis ◽  
Wide Range

The feasibility of applying dynamic imaging analysis technology to particle characterization has been evaluated for application in the water sector. A system has been developed which captures in-situ images of suspended particles in a flowing sample stream and analyzes these images in real time to determine particle size and concentration. The technology can measure samples having a wide range of particle sizes (∼1.5 to 1,000 μm equivalent circular diameter) and concentrations (<1 to >1 million/ml). The system also provides magnified images of particles for visual analysis of properties such as size, shape and grayscale level. There are no sample preparation requirements and statistically accurate results are produced in less than three minutes per sample. The overall system architecture is described. The major design challenges in developing a practical system include obtaining adequate contrast for the range of particle materials found in typical water samples and achieving this under operating conditions permitting an adequate sample processing rate for real time feedback of results. Performance of the instrument is reported in reference to industry accepted particle standards and applications as an analytical tool for the water industries are considered.

Model Based Control Concepts for Jet Engines

2001 ◽  
Author(s):  
Klaus Lietzau ◽  
Andreas Kreiner
Keyword(s):  
Turbine Blades ◽  
Engine Performance ◽  
Current Control ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Engine Model ◽  
Model Based ◽  
Safety Margins ◽  
Engine Life

Many jet engine variables cannot be measured in-flight or can only be measured with a complex, and hence unreliable, instrumentation system. This includes variables that are of imminent importance for the safe operation of the engine or for engine life, such as the temperature of the high pressure turbine blades or the surge margins of the turbo compressors, for instance. Current control systems therefore transform limits on these variables into limits on other variables measured by the engine’s sensors. This leads to increased safety margins and thus to non-optimal engine performance. An onboard engine model incorporated into the engine control system could provide information about all engine variables. This could enable further control and monitoring system optimisations leading to improved engine performance, reduced fuel consumption, increased safety and engine life. This paper explains the principle of model based engine control and gives an overview about possible applications for conventional and also thrust vectored jet engines. Modeling methods for real-time simulation as well as methods for online model adaptation are presented. The potential of model based jet engine control is analyzed and fortified by some prototype realizations.

scholarly journals Choice of Interceptor Aerodynamic Lifting Surface Location based on Autopilot Design Considerations

2021 ◽  
Vol 71 (1) ◽  
pp. 108-116
Author(s):  
Ram B. Sankar ◽  
P. K. Tiwari ◽  
B. Bandyopadhyay ◽  
H. Arya
Keyword(s):  
Center Of Pressure ◽  
Static Stability ◽  
Operating Conditions ◽  
Neutral Stability ◽  
Lifting Surface ◽  
Stability Point ◽  
Wide Range ◽  
Surface Location ◽  
Optimum Aerodynamic ◽  
And Control

Interceptors operate at wide range of operating conditions in terms of Mach number, altitude and angle of attack. The aerodynamic design caters for such wide operating envelope by appropriate sizing of lifting and control surfaces for meeting the normal acceleration capability requirements. The wide range of operating conditions leads to an inevitable spread in center of pressure location and hence spread in static stability. The performance of control design is a strong function of the aerodynamic static stability. The total operating envelope can be bifurcated into statically stable and unstable zones and the aerodynamic lifting surface location can be used as a control parameter to identify the neutral stability point. During the homing phase lesser static stability is desirable for good speed of response, hence the lifting surface location needs to be chosen based on the capability of control to handle instability. This paper analyses the limitations of autopilot design for the control of an unstable interceptor and brings out a method to identify the optimum aerodynamic lifting surface location for efficiently managing static margin while satisfying the control limitations and homing phase performance. This provides an input on the most appropriate lifting surface location to the aerodynamic designer during the initial CFD based aerodynamic characterisation stage itself, before commencing the rigorous wind tunnel based characterisation.

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