Design Considerations of a Versatile Simulator for High-Bypass Turbofans

1995 ◽  
Vol 117 (1) ◽  
pp. 31-37
Author(s):  
C. Balan
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Pressure Ratio ◽  
Large Diameter ◽  
Scale Model ◽  
Innovative Design ◽  
Design Considerations ◽  
Acoustic Impact ◽  
Thrust Reverser ◽  
New Generation

The continuing requirement for performance improvement of higher thrust turbofans is met by increased bypass ratios. The trend toward higher bypass ratios and relatively large-diameter low-pressure-ratio fans requires innovative design approaches, which include shorter inlets, slimmer nacelles, shorter fan ducts and exhaust systems, and possible elimination of thrust reverser. The success of this new generation of high-bypass ducted turbofans depends on understanding the acoustic impact from reduced treatment areas, inlet-fan coupling and operability, as well as overall system performance. To achieve these goals a versatile scale model propulsion simulator large enough to operate as a fan rig, yet small enough to be installed in a wind tunnel for evaluating overall acoustic, operability, and system performance, was developed. The criteria of designing such a simulator and its capabilities are discussed in this paper.

Design Considerations of a Versatile Simulator for High Bypass Turbofans

1993 ◽  
Author(s):  
Chellappa Balan
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Pressure Ratio ◽  
Large Diameter ◽  
Scale Model ◽  
Innovative Design ◽  
Design Considerations ◽  
Acoustic Impact ◽  
Thrust Reverser ◽  
New Generation

The continuing requirements for performance improvement of higher thrust turbofans is met by increased bypass ratios. The trend towards higher bypass ratios and relatively large diameter low pressure ratio fans require innovative design approaches which include shorter inlets, slimmer nacelles, shorter fan ducts and exhaust systems, and possible elimination of thrust reverser. The success of this new generation of high bypass ducted turbofans depends on understanding the acoustic impact from reduced treatment areas, inlet-fan coupling and operability, as well as overall system performance. To achieve these goals a versatile scale model propulsion simulator large enough to operate as a fan rig, yet small enough to be installed in a wind tunnel for evaluating overall acoustic, operability, and system performance was developed. The criteria of designing such a simulator and its capabilities are discussed in this paper.

scholarly journals Complex System Governance as a Framework for Asset Management

2021 ◽  
Vol 13 (15) ◽  
pp. 8502
Author(s):  
Polinpapilinho F. Katina ◽  
James C. Pyne ◽  
Charles B. Keating ◽  
Dragan Komljenovic
Keyword(s):  
Complex System ◽  
Performance Improvement ◽  
Asset Management ◽  
System Performance ◽  
Future Research ◽  
Complex Organizations ◽  
Potential Relationship ◽  
Structured Approach

Complex system governance (CSG) is an emerging field encompassing a framework for system performance improvement through the purposeful design, execution, and evolution of essential metasystem functions. The goal of this study was to understand how the domain of asset management (AsM) can leverage the capabilities of CSG. AsM emerged from engineering as a structured approach to organizing complex organizations to realize the value of assets while balancing performance, risks, costs, and other opportunities. However, there remains a scarcity of literature discussing the potential relationship between AsM and CSG. To initiate the closure of this gap, this research reviews the basics of AsM and the methods associated with realizing the value of assets. Then, the basics of CSG are provided along with how CSG might be leveraged to support AsM. We conclude the research with the implications for AsM and suggested future research.

BER performance analysis of FSO using hybrid-SIM technique with APD receiver over weak and strong turbulence channels

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajat Kumar Giri
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Avalanche Photodiode ◽  
Free Space Optical ◽  
Error Performance ◽  
Strong Turbulence ◽  
Meijer G Function ◽  
Hermite Approximation ◽  
Ber Performance ◽  
Better Than

Abstract In this paper, a hybrid-subcarrier-intensity-modulation (hybrid-SIM) technique for the performance improvement of free-space-optical (FSO) communication system has been proposed. Subsequently, for further error performance improvement, avalanche photodiode (APD) based receiver is used in the proposed system. The system performance is analyzed at various atmospheric turbulence levels over weak and strong turbulence channels. The bit error rate (BER) is theoretically derived using Gauss–Hermite approximation and Meijer-G function and it is simulated in the MATLAB environment. The simulation result shows that the BER performance of hybrid-SIM is better than BPSK-SIM technique irrespective of the channel types and also the significant BER performance improvement is observed by APD receiver.

Investigation on a Blockerless Cascade Thrust Reverser System Based on Response Surface Method

2018 ◽  
Author(s):  
Li Zhou ◽  
Zhanxue Wang ◽  
Jingwei Shi ◽  
Xiaobo Zhang
Keyword(s):  
High Pressure ◽  
Secondary Flow ◽  
Response Surface ◽  
Response Surface Method ◽  
Interaction Effect ◽  
Pressure Ratio ◽  
Surface Method ◽  
Thrust Reverser ◽  
Reverse Thrust ◽  
Secondary Injection

The blockerless cascade thrust reverser is one of the innovative thrust reverser systems, which replaces the traditionally mechanical blocker door with the aerodynamic blocker door by high-pressure secondary injection, thus significantly reduces the nacelle weight and the complexity of the actuator, and especially suitable for high-bypass-ratio turbofan engine. In order to obtain the optimum performance of a blockerless cascade thrust reverser system and provide the guidance for the design of the blockerless cascade thrust reverser system, a blockerless cascade thrust reverser system was studied in this paper based on the Response Surface Method (RSM), focusing on the effect of different geometric and aerodynamic parameters on the thrust reverser performance. Results show that the secondary injection with high pressure forms the blockage effect to the fan flow, then forces the fan flow to deflect and discharge from the cascade window, realizing the reverse thrust. The thrust reverser performance is mainly affected by fan pressure ratio (FPR), secondary flow pressure ratio (SPR), secondary injection position (Xjet), secondary injection angle (αjet) and cascade installation angle (β), and the dominated factors are FPR, SPR and Xjet. According to the obtained response equation of the thrust reverser performance, the relationship between reverse thrust efficiency and various parameters are clearly described, and performance of thrust reverser can be quickly evaluated. Significant interaction effects exist between different two factors, which must be taken into consideration in the design process of the blockerless cascade thrust reverser system, especially for the interaction effect between FPR and Xjet, interaction effect between FPR and β. Optimization design with objective of maximum reverse thrust was carried out to determine the best parameter settings, and reverse thrust ratio ηTrev of 60% is achieved under the constraint of the secondary flow ratio.

Map Width Enhancement Technique for a Turbocharger Compressor

2013 ◽  
Vol 136 (6) ◽  
Author(s):  
Subenuka Sivagnanasundaram ◽  
Stephen Spence ◽  
Juliana Early
Keyword(s):  
Performance Improvement ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Comparison Study ◽  
Heavy Duty ◽  
Recirculating Flow ◽  
Heavy Duty Diesel ◽  
And Performance ◽  
The Stability ◽  
The Impact

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

scholarly journals Fault Analysis of a Gas Turbine HTGR

1976 ◽  
Author(s):  
R. Chmielewski ◽  
K. Vepa ◽  
L. Cheng ◽  
J. Bowyer
Keyword(s):  
Gas Turbine ◽  
Failure Modes ◽  
Pressure Ratio ◽  
Power Conversion ◽  
Reactor Core ◽  
Pressure Change ◽  
Fault Analysis ◽  
Preliminary Evaluation ◽  
Design Considerations ◽  
Disk Failures

The Gas Turbine High Temperature Gas-Cooled Reactor combines a helium-cooled reactor core of established design with a closed-cycle helium turbine power-conversion system. This paper discusses the design considerations which mitigate the consequences of failure of the rotating machinery located within the reactor vessel. The methods of analysis and summary of results are presented for the failure modes of most concern. The spectrum of potential incidents which have been evaluated include turbine blade, rim, and disk failures. The requirements and design methods for rotor containment are discussed. The turbomachine maintains a pressure ratio of about two between the high and low pressure portions of the loop; postulated failures can, therefore, lead to rapid rates of pressure change. The preliminary evaluation of this internal pressure equilibration is presented.

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