The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Daniel Crichton - One of the best experts on this subject based on the ideXlab platform.

  • Engine Design studies for a silent aircraft
    Journal of Turbomachinery-transactions of The Asme, 2007
    Co-Authors: Cesare A Hall, Daniel Crichton
    Abstract:

    The Silent Aircraft Initiative is a research project funded by the Cambridge-MIT Institute aimed at reducing aircraft noise to the point where it is imperceptible in the urban environments around airports. The propulsion system being developed for this project has a thermodynamic cycle based on an ultrahigh bypass ratio turbofan combined with a variable area exhaust nozzle and an embedded installation. This cycle has been matched to the flight mission and thrust requirements of an all-lifting body airframe, and through precise scheduling of the variable exhaust nozzle, the Engine operating conditions have been optimized for maximum thrust at top-of-climb, minimum fuel consumption during cruise, and minimum jet noise at low altitude. This paper proposes Engine mechanical arrangements that can meet the cycle requirements and, when installed in an appropriate airframe, will be quiet relative to current turbofans. To reduce the Engine weight, a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An Engine configuration with three fans driven by a single core is also presented, and this is expected to have further weight, fuel burn, and noise benefits.

  • Challenges in the Silent Aircraft Engine Design
    45th AIAA Aerospace Sciences Meeting and Exhibit, 2007
    Co-Authors: E. De La Rosa Blanco, Cesare Hall, Daniel Crichton
    Abstract:

    The Silent Aircraft Initiative goal is to Design an aircraft that is imperceptible above background noise outside the airport boundary. The aircraft that fulfils this objective must also be economically competitive with conventional aircraft of the future and therefore fuel consumption and mechanical reliability are key considerations for the Design. To meet these ambitious targets, a multi-fan embedded turbofan Engine with boundary layer ingestion has been proposed. This configuration includes several new technologies including a variable area nozzle, a complex high-power transmission system, a Low Pressure turbine Designed for lownoise, an axial-radial HP compressor, advanced acoustic liners and a low-speed fan optimized for both cruise and off-Design operation. These technologies, in combination, enable a low-noise and fuel efficient propulsion system but they also introduce significant challenges into the Design. These challenges include difficulties in predicting the noise and performance of the new components but there are also challenges in reducing the Design risks and proving that the new concepts are realizable. This paper presents the details of the Engine configuration that has been developed for the Silent Aircraft application. It describes the Design approach used for the critical components and discusses the benefits of the new technologies. The new technologies are expected to offer significant benefits in noise reduction without compromising fuel burn. However, more detailed Design and further research are required to fully control the additional risks generated by the system complexity.

  • Engine Design studies for a silent aircraft
    ASME Turbo Expo 2006: Power for Land Sea and Air, 2006
    Co-Authors: Cesare A Hall, Daniel Crichton
    Abstract:

    The Silent Aircraft Initiative is a research project funded by the Cambridge-MIT Institute aimed at reducing aircraft noise to the point where it is imperceptible in the urban environments around airports. The propulsion system being developed for this project has a thermodynamic cycle based on an ultra-high bypass ratio turbofan combined with a variable area exhaust nozzle and an embedded installation. This cycle has been matched to the flight mission and thrust requirements of an all-lifting body airframe, and through precise scheduling of the variable exhaust nozzle, the Engine operating conditions have been optimized for maximum thrust at top-of-climb, minimum fuel consumption during cruise and minimum jet noise at low altitude. This paper proposes Engine mechanical arrangements that can meet the cycle requirements and, when installed in an appropriate airframe, will be quiet relative to current turbofans. To reduce the Engine weight a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An Engine configuration with three fans driven by a single core is also presented and this is expected to have further weight, fuel burn and noise benefits.Copyright © 2006 by ASME

Guven Gonca - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic analysis and performance maps for the irreversible dual atkinson cycle Engine dace with considerations of temperature dependent specific heats heat transfer and friction losses
    Energy Conversion and Management, 2016
    Co-Authors: Guven Gonca
    Abstract:

    Abstract A comprehensive performance analysis depending on the non-dimensional power output, effective power, non-dimensional power density, effective power density, thermal efficiency, effective efficiency, maximum power output (MP), maximum power density (MPD) and maximum thermal efficiency (MEF) criteria has been conducted for the irreversible Dual–Atkinson cycle Engine (DACE) which includes internal irreversibilities by virtue of the irreversible-adiabatic compression process, expansion process, heat transfer and friction losses. In the analyses, Classical Thermodynamics Modeling (CTM) and a new realistic Finite-Time Thermodynamics Modeling (FTTM) have been used. The power output, power density and thermal efficiency are obtained with respect to the variation of the pressure ratio, cut-off ratio, stroke ratio, Atkinson cycle ratio, cycle pressure ratio and cycle temperature ratio. The effects of the Engine Design and operating parameters on the general and maximum performances of the DACE have been investigated with respect to the variation of the cycle pressure ratio and cycle temperature ratio in the CTM section. The influences of the other Engine Design and operating parameters such as Engine speed, mean piston speed, stroke length, equivalence ratio, compression ratio and bore–stroke length ratio on the Engine performance have been investigated in the FTTM section. In addition, the energy losses depending on incomplete combustion, friction, heat transfer and exhaust output have been described as fuel input energy. In order to obtain realistic results, temperature-dependent specific heats for working fluid have been used. The DACE is a new concept for internal combustion Engines and just a few studies have been carried out. This study presents new contributions to the analysis of the Dual–Atkinson cycle Engines in terms of the effects of Engine Design and operating parameters on the Engine performance. Because CTM, FTTM, energy losses, power density and MPD analyses, for the DACE are newly presented just in this study.

  • the influences of the Engine Design and operating parameters on the performance of a turbocharged and steam injected diesel Engine running with the miller cycle
    Applied Mathematical Modelling, 2016
    Co-Authors: Guven Gonca, Bahri Sahin
    Abstract:

    Abstract This study reports the influences of the Engine Design and operating parameters on the performance of a turbocharged, steam injected and Miller cycle diesel Engine by using a simulation model based on the finite-time thermodynamics. The model is validated with experimental data and the effects of various Engine Design and operating parameters such as cycle temperature ratio, cycle pressure ratio, friction coefficient, Engine speed, mean piston speed, stroke length, inlet temperature, inlet pressure, equivalence ratio, compression ratio, steam ratio, retarding angle and bore-stroke length ratio on the effective power and effective efficiency are investigated. Furthermore, the energy losses originating from incomplete combustion, friction, heat transfer and exhaust output are demonstrated by using figures. The results show that the Engine performance increases with increasing some parameters such as cycle temperature ratio, cycle pressure ratio, inlet pressure; with decreasing some parameters such as friction coefficient, inlet temperature, steam ratio, retarding angle of intake valve closing. However, the Engine performance could increase or decrease with respect to different conditions for some parameters such as Engine speed, mean piston speed, stroke length, equivalence ratio and compression ratio.

  • comprehensive performance analyses and optimization of the irreversible thermodynamic cycle Engines tce under maximum power mp and maximum power density mpd conditions
    Applied Thermal Engineering, 2015
    Co-Authors: Guven Gonca, Bahri Sahin, Yasin Ust, Adnan Parlak
    Abstract:

    Abstract This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic cycle Engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the cycles are obtained by using Engine Design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller cycle ratio, exhaust temperature ratio, cycle temperature ratio and cycle pressure ratio. The effects of Engine Design parameters on the maximum and optimal performances are investigated.

Mazdak Hooshang - One of the best experts on this subject based on the ideXlab platform.

  • optimization of stirling Engine Design parameters using neural networks
    Renewable Energy, 2015
    Co-Authors: Mazdak Hooshang, Askari R Moghadam, Ali Shaygan Nia, Tale M Masouleh
    Abstract:

    This paper presents a new optimization procedure for Stirling Engines based on neural network concepts. Based on modeling and experimental data an intelligent and fast method is proposed which finds the best values for different Design variables. Design variables of Stirling Engine are optimized using Multi-Layer Perceptron (MLP) neural networks. The optimization procedure is performed for three typical Design variables for a given precision which has the capability to be extended for various types of Engines and Designs.

Silvio Vaschetto - One of the best experts on this subject based on the ideXlab platform.

  • Integrated Generator for More Electric Engine: Design and Testing of a Scaled-Size Prototype
    IEEE Transactions on Industry Applications, 2013
    Co-Authors: Andrea Cavagnino, Alberto Tenconi, Silvio Vaschetto
    Abstract:

    In this paper, the main Design characteristics of a scaled-size prototype of an integrated generator for More Electric Engine application are presented. The reference electrical machine is a surface-mounted permanent-magnet machine directly integrated inside the aircraft main gas turbine Engine. Therefore, as for the reference machine, the Designed scaled-size prototype is characterized by an annulus-shape outer-rotor structure, and it is cooled by air flowing through the airgap. To satisfy the fault-tolerant requirements imposed by the aerospace application, the stator winding is constituted by multiphase single-layer nonoverlapping fractional-slot concentrated windings. In order to validate the Designed machine, the experimental results of tests conducted on the prototype are reported. Among these ones, particular interest is focused on the cooling capabilities of the cooling air which flows through the machine airgap. Furthermore, based on the reduced-scale prototype experience, some considerations and the main Design characteristics of the full-size machine Design are reported too.

  • Integrated generator for more electric Engine: Design and testing of a scaled size prototype
    2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012
    Co-Authors: Andrea Cavagnino, Alberto Tenconi, Zijian Li, Silvio Vaschetto
    Abstract:

    In this paper the main Design characteristics of a scaled-size prototype of an integrated generator for More Electric Engine (MEE) application are presented. The reference electrical machine is a surface mounted PM machine directly integrated inside the aircraft main gas turbine Engine. Therefore, as for the reference machine, the Designed scaled-size prototype is characterized by an annulus shape outer rotor structure and it is cooled by air flowing through the airgap. To satisfy the fault-tolerant requirements imposed by the aerospace application, the stator winding is constituted by multiphase single-layer non-overlapping fractional-slot concentrated windings. In order to validate the Designed machine, the experimental results of tests conducted on the prototype are reported. Among these ones, particular interest is focused on the cooling capabilities of the cooling air which flow through the machine airgap. Furthermore, based on the reduced scale prototype experience, some considerations and the main Design characteristics of the full-size machine Design are reported too.

Tale M Masouleh - One of the best experts on this subject based on the ideXlab platform.

  • optimization of stirling Engine Design parameters using neural networks
    Renewable Energy, 2015
    Co-Authors: Mazdak Hooshang, Askari R Moghadam, Ali Shaygan Nia, Tale M Masouleh
    Abstract:

    This paper presents a new optimization procedure for Stirling Engines based on neural network concepts. Based on modeling and experimental data an intelligent and fast method is proposed which finds the best values for different Design variables. Design variables of Stirling Engine are optimized using Multi-Layer Perceptron (MLP) neural networks. The optimization procedure is performed for three typical Design variables for a given precision which has the capability to be extended for various types of Engines and Designs.