The Experts below are selected from a list of 10722 Experts worldwide ranked by ideXlab platform
Hyoungjin Kim - One of the best experts on this subject based on the ideXlab platform.
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Flow simulation and optimal shape design of N3-X hybrid wing body configuration using a body force method
Aerospace Science and Technology, 2017Co-Authors: Hyoungjin Kim, Meng-sing LiouAbstract:System studies show that NASA's N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals of N+3 generation transports (three generations beyond the current air transport technology level). In this paper, we present flow calculations and shape optimization of the integrated N3-X configuration, including the mail-slot propulsor, based on an unstructured-mesh Navier–Stokes solver. To simulate the propulsor fans flow, a novel body force model is suggested for a realistic and efficient representation of flow Turning, Pressure rise and losses resulting from the fan blades and the inlet-fan interactions for distorted inflow conditions. This work is the first of its kind analysis and design study on boundary layer ingestion inlet and fan interaction problems using the body force method. A mail-slot geometry was generated and installed on the N3-X configuration with an efficient CAD-free method. An optimal shape design of the mail-slot nacelle surface with the adjoint method was successfully conducted to reduce the strength of shock waves and flow separations on the cowl surface.
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Mail-Slot Nacelle Shape Design for N3-X Hybrid Wing-Body Configuration
51st AIAA SAE ASEE Joint Propulsion Conference, 2015Co-Authors: Hyoungjin Kim, May-fun Liou, Meng-sing LiouAbstract:System studies show that NASA’s N3–X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level). In this paper, we present Navier-Stokes flow simulations of N3–X on hybrid unstructured meshes, including the mail-slot propulsor. A novel body force model generation approach is suggested for a realistic and efficient representation of flow Turning, Pressure rise and losses resulting from the fan blades and the inlet-fan interactions. A new version of mail-slot installation on the N3-X configuration was tested. An optimal shape design of the mail-slot nacelle surface was conducted to reduce the strength of shock waves and flow separations on the cowl surface.
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Optimal Shape Design of Mail-Slot Nacelle on N3-X Hybrid Wing-Body Configuration
31st AIAA Applied Aerodynamics Conference, 2013Co-Authors: Hyoungjin Kim, Ms M.-s. Meng-sing Liou, X Hybrid Wing-body ConfigurationAbstract:System studies show that a N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level) set by NASA's Subsonic Fixed Wing Project. In this study, a Navier-Stokes flow simulation of N3-X on hybrid unstructured meshes was conducted, including the mail-slot propulsor. The geometry of the mail-slot propulsor was generated by a CAD (Computer-Aided Design)-free shape parameterization. A novel body force model generation approach was suggested for a more realistic and efficient simulation of the flow Turning, Pressure rise and loss effects of the fan blades and the inlet-fan interactions. Flow simulation results of the N3-X demonstrates the validity of the present approach. An optimal Shape design of the mail-slot nacelle surface was conducted to reduce strength of shock waves and flow separations on the cowl surface.
Meng-sing Liou - One of the best experts on this subject based on the ideXlab platform.
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Flow simulation and optimal shape design of N3-X hybrid wing body configuration using a body force method
Aerospace Science and Technology, 2017Co-Authors: Hyoungjin Kim, Meng-sing LiouAbstract:System studies show that NASA's N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals of N+3 generation transports (three generations beyond the current air transport technology level). In this paper, we present flow calculations and shape optimization of the integrated N3-X configuration, including the mail-slot propulsor, based on an unstructured-mesh Navier–Stokes solver. To simulate the propulsor fans flow, a novel body force model is suggested for a realistic and efficient representation of flow Turning, Pressure rise and losses resulting from the fan blades and the inlet-fan interactions for distorted inflow conditions. This work is the first of its kind analysis and design study on boundary layer ingestion inlet and fan interaction problems using the body force method. A mail-slot geometry was generated and installed on the N3-X configuration with an efficient CAD-free method. An optimal shape design of the mail-slot nacelle surface with the adjoint method was successfully conducted to reduce the strength of shock waves and flow separations on the cowl surface.
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Mail-Slot Nacelle Shape Design for N3-X Hybrid Wing-Body Configuration
51st AIAA SAE ASEE Joint Propulsion Conference, 2015Co-Authors: Hyoungjin Kim, May-fun Liou, Meng-sing LiouAbstract:System studies show that NASA’s N3–X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level). In this paper, we present Navier-Stokes flow simulations of N3–X on hybrid unstructured meshes, including the mail-slot propulsor. A novel body force model generation approach is suggested for a realistic and efficient representation of flow Turning, Pressure rise and losses resulting from the fan blades and the inlet-fan interactions. A new version of mail-slot installation on the N3-X configuration was tested. An optimal shape design of the mail-slot nacelle surface was conducted to reduce the strength of shock waves and flow separations on the cowl surface.
Yifang Gong - One of the best experts on this subject based on the ideXlab platform.
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Development of a coupled supersonic inlet-fan Navier–Stokes simulation method
Chinese Journal of Aeronautics, 2018Co-Authors: Li Qiushi, Yongzhao Lyu, Tianyu Pan, Yifang GongAbstract:Abstract A coupled supersonic inlet-fan Navier–Stokes simulation method was developed by using COMSOL-CFD code. The flow Turning, Pressure rise and loss effects across blade rows of the fan and the inlet-fan interactions were taken into account as source terms of the governing equations without a blade geometry by a body force model. In this model, viscous effects in blade passages can also be calculated directly, which include the exchange of momentum between fluids and detailed viscous flow close to walls. NASA Rotor 37 compressor test rig was used to validate the ability of the body force model to estimate the real performance of blade rows. Calculated Pressure ratio characteristics and the distribution of the total Pressure, total temperature, and swirl angle in the span direction agreed well with experimental and numerical data. It is shown that the body force model is a promising approach for predicting the flow field of the turbomachinery. Then, coupled axisymmetric mixed compression supersonic inlet-fan simulations were conducted at Mach number 2.8 operating conditions. The analysis includes coupled steady-state performance, and effects of the fan on the inlet. The results indicate that the coupled simulation method is capable of simulating behavior of the supersonic inlet-fan system.
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Development of a coupled supersonic inlet-fan Navier–Stokes simulation method
Elsevier, 2018Co-Authors: Yongzhao Lyu, Tianyu Pan, Yifang GongAbstract:A coupled supersonic inlet-fan Navier–Stokes simulation method was developed by using COMSOL-CFD code. The flow Turning, Pressure rise and loss effects across blade rows of the fan and the inlet-fan interactions were taken into account as source terms of the governing equations without a blade geometry by a body force model. In this model, viscous effects in blade passages can also be calculated directly, which include the exchange of momentum between fluids and detailed viscous flow close to walls. NASA Rotor 37 compressor test rig was used to validate the ability of the body force model to estimate the real performance of blade rows. Calculated Pressure ratio characteristics and the distribution of the total Pressure, total temperature, and swirl angle in the span direction agreed well with experimental and numerical data. It is shown that the body force model is a promising approach for predicting the flow field of the turbomachinery. Then, coupled axisymmetric mixed compression supersonic inlet-fan simulations were conducted at Mach number 2.8 operating conditions. The analysis includes coupled steady-state performance, and effects of the fan on the inlet. The results indicate that the coupled simulation method is capable of simulating behavior of the supersonic inlet-fan system. Keywords: Body force model, Coupled simulation, Rapid numerical method, Supersonic inlet-fan, Viscous flo
Tim Schneider - One of the best experts on this subject based on the ideXlab platform.
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Investigations on Aerodynamic Loading Limits of Subsonic Compressor Tandem Cascades: End Wall Flow
Volume 2A: Turbomachinery, 2014Co-Authors: Charlotte Hertel, Christoph Bode, Dragan Kožulović, Tim SchneiderAbstract:An optimized subsonic compressor tandem cascade was investigated experimentally and numerically. Since the design aims at applications under incompressible flow conditions, a low inlet Mach number of 0.175 was used. The experiments were carried out at the low speed cascade wind tunnel at the Technische Universitat Braunschweig. For the numerical simulations, the CFD-solver TRACE of DLR Cologne was used, together with a curvature corrected k-ω turbulence model and the γ-Reθ transition model. The aerodynamic loading was varied by incidence variation. Results are presented and discussed for different inlet angles: spanwise loss coefficient, Turning, Pressure rise coefficient and AVR together with contour plots of the wake plane, flow visualization and oil flow pictures. Experimental and numerical results were compared and found to be in good agreement. The secondary flow topology of the front blade is considerably altered by the aerodynamic loading variation, whereas the topology of the rear blade surface is almost unchanged. The effect of the nozzle between the tandem blades, was observable up to the end wall for all investigated incidences. In addition, a comparison is made to published results of previous experimental and numerical investigations of a transonic tandem compressor cascade [1] and its reference single compressor cascade [2]. The comparison of the tandem cascades revealed that the general structures of the secondary flow seem to be similar for similar loading.Copyright © 2014 by ASME
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Investigations on Aerodynamic Loading Limits of Subsonic Compressor Tandem Cascades: Midspan Flow
Volume 1: Advances in Aerodynamics, 2013Co-Authors: Charlotte Hertel, Christoph Bode, Dragan Kožulović, Tim SchneiderAbstract:An optimized subsonic compressor tandem cascade was investigated experimentally and numerically. Since the design aims at incompressible applications, a low inlet Mach number of 0.175 was used. The experiments were carried out at the low speed cascade wind tunnel at the Technische Universitat Braunschweig. For the numerical simulations, the CFD-solver TRACE of DLR Cologne was used, together with a curvature corrected k-ω turbulence model and the γ-Reθ transition model. Besides the incidence variation, the aerodynamic loading has also been varied by contracting endwalls. Results are presented and discussed for different inlet angles and endwall contractions: Pressure distribution, loss coefficient, Turning, Pressure rise, AVDR and Mach number. The comparison of experimental and numerical results is always adequate for a large range of incidence. In addition, a comparison is made to an existing high subsonic tandem cascade and conventional cascades. For the latter the Lieblein diffusion factor has been employed as a measure of aerodynamic loading to complete the Lieblein Chart of McGlumphy [1].© 2013 ASME
Yongzhao Lyu - One of the best experts on this subject based on the ideXlab platform.
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Development of a coupled supersonic inlet-fan Navier–Stokes simulation method
Chinese Journal of Aeronautics, 2018Co-Authors: Li Qiushi, Yongzhao Lyu, Tianyu Pan, Yifang GongAbstract:Abstract A coupled supersonic inlet-fan Navier–Stokes simulation method was developed by using COMSOL-CFD code. The flow Turning, Pressure rise and loss effects across blade rows of the fan and the inlet-fan interactions were taken into account as source terms of the governing equations without a blade geometry by a body force model. In this model, viscous effects in blade passages can also be calculated directly, which include the exchange of momentum between fluids and detailed viscous flow close to walls. NASA Rotor 37 compressor test rig was used to validate the ability of the body force model to estimate the real performance of blade rows. Calculated Pressure ratio characteristics and the distribution of the total Pressure, total temperature, and swirl angle in the span direction agreed well with experimental and numerical data. It is shown that the body force model is a promising approach for predicting the flow field of the turbomachinery. Then, coupled axisymmetric mixed compression supersonic inlet-fan simulations were conducted at Mach number 2.8 operating conditions. The analysis includes coupled steady-state performance, and effects of the fan on the inlet. The results indicate that the coupled simulation method is capable of simulating behavior of the supersonic inlet-fan system.
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Development of a coupled supersonic inlet-fan Navier–Stokes simulation method
Elsevier, 2018Co-Authors: Yongzhao Lyu, Tianyu Pan, Yifang GongAbstract:A coupled supersonic inlet-fan Navier–Stokes simulation method was developed by using COMSOL-CFD code. The flow Turning, Pressure rise and loss effects across blade rows of the fan and the inlet-fan interactions were taken into account as source terms of the governing equations without a blade geometry by a body force model. In this model, viscous effects in blade passages can also be calculated directly, which include the exchange of momentum between fluids and detailed viscous flow close to walls. NASA Rotor 37 compressor test rig was used to validate the ability of the body force model to estimate the real performance of blade rows. Calculated Pressure ratio characteristics and the distribution of the total Pressure, total temperature, and swirl angle in the span direction agreed well with experimental and numerical data. It is shown that the body force model is a promising approach for predicting the flow field of the turbomachinery. Then, coupled axisymmetric mixed compression supersonic inlet-fan simulations were conducted at Mach number 2.8 operating conditions. The analysis includes coupled steady-state performance, and effects of the fan on the inlet. The results indicate that the coupled simulation method is capable of simulating behavior of the supersonic inlet-fan system. Keywords: Body force model, Coupled simulation, Rapid numerical method, Supersonic inlet-fan, Viscous flo
