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Aerodynamics and Fluid Mechanics Commons

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Blended Wing Body Propulsion System Design, Parth Kumar, Adeel Khalid 2017 Georgia Institute of Technology

Blended Wing Body Propulsion System Design, Parth Kumar, Adeel Khalid

International Journal of Aviation, Aeronautics, and Aerospace

This research paper focuses on the optimization of the propulsion system of a blended wing body design. Two different aspects of the design, the engine placement and count, and the engine itself, are investigated. The preliminary wing of the BWB is created through aerodynamic analysis, and is kept as a constant over the different propulsion system configurations. The engine parameters are first investigated. Equations are derived to express takeoff distance and climb rate as a function of engine sea level thrust, cruise thrust, and the number of engines. Nearly 150 different engine models, in BWB configurations of 2, 3, 4 ...


Wingtip Vortex Alleviation Using A Reverse Delta Type Add-On Device, Afaq Altaf 2017 New York Institute of Technology

Wingtip Vortex Alleviation Using A Reverse Delta Type Add-On Device, Afaq Altaf

International Journal of Aviation, Aeronautics, and Aerospace

The result of interactions of a wingtip vortex of a half-span wing and vortices generated by a slender reverse delta type add-on device were studied using Particle Image Velocimetry in a closed-loop low-speed wind tunnel. Characteristics of the vortex interactions produced downstream in planes perpendicular to the free stream direction at a mean chord-based Reynolds number, Rec = 2.75×105, are explored in this work. The study reveals that the reverse delta type add-on device considerably reduces the tangential velocity, vorticity and circulation magnitude of the resultant vortex by up to 79.6%, 85.6% and 48.7 ...


Estimation Of Turbulence Effects On Wind-Induced Suctions On The Roof Of A Low-Rise Building, Chieh-Hsun Wu 2017 The University of Western Ontario

Estimation Of Turbulence Effects On Wind-Induced Suctions On The Roof Of A Low-Rise Building, Chieh-Hsun Wu

Electronic Thesis and Dissertation Repository

The effects of turbulence in the atmospheric boundary layer (ABL) on surface pressures of a typical low-rise building roof are investigated in this thesis. A 1/50 geometrically-scaled model of the Texas Tech University Wind Engineering Field Research Lab (WERFL) building model is used for pressure measurements in wind tunnel experiments. ABL wind turbulence intensities ranging from about 10% to 30%, and length scales ranging from 6 to 12 times of the building height (H) are generated. The effects of ABL turbulence on the mean roof pressures within the separated flow are explained from the time-averaged Navier-Stokes equations. The pressure ...


Design And Validation Of Pressure Based Flow Rate Soft Sensor For Freeze-Drying, Pasita Pibulchinda, Tong Zhu, Vaibhav Kshirsagar, Alina A. Alexeenko 2017 Purdue University

Design And Validation Of Pressure Based Flow Rate Soft Sensor For Freeze-Drying, Pasita Pibulchinda, Tong Zhu, Vaibhav Kshirsagar, Alina A. Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lyophilization or freeze drying is a process of removing water by sublimation. It is commonly used to extend the shelf life of drugs in the pharmaceutical industry. Because the process is costly and time consuming, precise and efficient pressure, temperature control and drying time estimation are required. It is the goal of freeze-drying to run at maximum capacity while staying within the safe zone by carefully controlling the sublimation rate. Currently, real time estimation of sublimation rate is still challenging. The technique available called Tunable diode laser absorption spectroscopy (TDLAS) is invasive, and requires major modifications. The current study focuses ...


Wind Farm Power Prediction In Complex Terrain, Micah Sandusky 2017 Boise State University

Wind Farm Power Prediction In Complex Terrain, Micah Sandusky

Boise State University Theses and Dissertations

There has been increasing interest in predicting the velocity field within wind farms in complex terrain for resource assessment, turbine siting, and power forecasting. These capabilities are made possible by advancements in computational speed from a new generation of computing hardware and numerical methods. The current thesis research focuses on two technical components to advance the current state in wind power forecasting. The first component is improved prediction of wind flow over complex terrain using the versatile immersed boundary method to represent surface boundary conditions on a fixed Cartesian mesh. The proposed approach embodies the law-of-the-wall for rough surfaces and ...


Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, Kai Wang, Umesh Vaidya, Baskar Ganapathysubramanian, Hui Hu 2017 Iowa State University

Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, Kai Wang, Umesh Vaidya, Baskar Ganapathysubramanian, Hui Hu

Umesh Vaidya

The objective of this paper is to compare the existing methods and develop novel approaches for the experimental data analysis of the unsteady aerodynamics of the flapping wing microaerial-vehicle. These methods are developed for the purpose of identification of the beneficial dynamics and for the development of reduced order models for control design. We first employ Proper Orthogonal Decomposition (POD) method for the data analysis of the PIV measurements in the wakes of piezoelectric flapping wings. The basic idea behind POD based data analysis method is to decompose the time series snapshots of PIV measurements into high energy, POD, modes ...


Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, Kai Wang, Umesh Vaidya, Baskar Ganapathysubramanian, Hui Hu 2017 Iowa State University

Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, Kai Wang, Umesh Vaidya, Baskar Ganapathysubramanian, Hui Hu

Baskar Ganapathysubramanian

The objective of this paper is to compare the existing methods and develop novel approaches for the experimental data analysis of the unsteady aerodynamics of the flapping wing microaerial-vehicle. These methods are developed for the purpose of identification of the beneficial dynamics and for the development of reduced order models for control design. We first employ Proper Orthogonal Decomposition (POD) method for the data analysis of the PIV measurements in the wakes of piezoelectric flapping wings. The basic idea behind POD based data analysis method is to decompose the time series snapshots of PIV measurements into high energy, POD, modes ...


Turbulent Combustion Of Polydisperse Evaporating Sprays With Droplet Crossing: Eulerian Modeling And Validation In The Infinite Knudsen Limit, S. de Chaisemartin, L. Freret, D. Kah, F. Laurent, Rodney O. Fox, J. Reveillon, M. Massot 2017 Ecole Centrale Paris

Turbulent Combustion Of Polydisperse Evaporating Sprays With Droplet Crossing: Eulerian Modeling And Validation In The Infinite Knudsen Limit, S. De Chaisemartin, L. Freret, D. Kah, F. Laurent, Rodney O. Fox, J. Reveillon, M. Massot

Rodney O. Fox

The accurate simulation of the dynamics of polydisperse evaporating sprays in unsteady gaseous flows with large-scale vortical structures is both a crucial issue for industrial applications and a challenge for modeling and scientific computing. The difficulties encountered by the usual Lagrangian approaches make the use of Eulerian models attractive, aiming at a lower cost and an easier coupling with the carrier gaseous phase. Among these models, the multi-fluid model allows for a detailed description of the polydispersity and size-velocity correlations for droplets of various sizes. The purpose of the present study is twofold. First, we extend the multi-fluid model in ...


Numerical Description Of Dilute Particle-Laden Flows By A Quadrature-Based Moment Method, N. Le Lostec, Rodney O. Fox, O. Simonin, P. Villedieu 2017 Office National d'Etudes et de Recherches Aerospatiales, France

Numerical Description Of Dilute Particle-Laden Flows By A Quadrature-Based Moment Method, N. Le Lostec, Rodney O. Fox, O. Simonin, P. Villedieu

Rodney O. Fox

The numerical simulation of gas-particle flows is divided into two families of methods. In Euler-Lagrange methods individual particle trajectories are computed, whereas in Euler-Euler methods particles are characterized by statistical descriptors. Lagrangian methods are very precise but their computational cost increases with instationarity and particle volume fraction. In Eulerian methods (also called moment methods) the particle-phase computational cost is comparable to that of the fluid phase but requires strong simplificaions. Existing Eulerian models consider unimodal or close-to-equilibrium particle velocity distributions and then fail when the actual distribution is far from equilibrium. Quadrature-based Eulerian methods introduce a new reconstruction of the ...


A Quadrature-Based Moment Closure For The Williams Spray Equation, O. Desjardins, Rodney O. Fox, P. Villedieu 2017 Iowa State University

A Quadrature-Based Moment Closure For The Williams Spray Equation, O. Desjardins, Rodney O. Fox, P. Villedieu

Rodney O. Fox

Sprays and other dispersed-phase systems can be described by a kinetic equation containing terms for spatial transport, acceleration, and particle processes (such as evaporation or collisions). In principle, the kinetic description is valid from the dilute (non-collisional) to the dense limit. However, its numerical solution in multi-dimensional systems is intractable due to the large number of independent variables. As an alternative, Lagrangian methods "discretize" the density function into "parcels" that are simulated using Monte-Carlo methods. While quite accurate, as in any statistical approach, Lagrangian methods require a relatively large number of parcels to control statistical noise, and thus are computationally ...


Leading Edge Boundary Layer Suction Device For The Cal Poly Rolling Road Wind Tunnel, Daniel C. Glover, Liam M. Madden, Robert J. Cabri 2017 California Polytechnic State University, San Luis Obispo

Leading Edge Boundary Layer Suction Device For The Cal Poly Rolling Road Wind Tunnel, Daniel C. Glover, Liam M. Madden, Robert J. Cabri

Mechanical Engineering

No abstract provided.


An Investigation Of Avian Wing Tip Vortex Generation Using A Biomimetic Approach, David Stewart Martin 2017 California Polytechnic State University, San Luis Obispo

An Investigation Of Avian Wing Tip Vortex Generation Using A Biomimetic Approach, David Stewart Martin

Master's Theses and Project Reports

An experimental study has been conducted to develop a process allowing the creation of biologically accurate aerodynamic test models mimicking the slotted primary feather geometry of the Brown Pelican (Pelecanus occidentalis). Preserved examples of both a full Brown Pelican wing and a single primary feather were 3D scanned and digitally reconstructed using a combination of MATLAB and CAD software. The final model was then 3D printed as a collection of smaller components using a LulzBot TAZ 6 printer and Taulman3D T-Glase PET filament. After using various surface finishing techniques to improve the finish of all 3D printed parts, an assembly ...


Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul 2017 California Polytechnic State University, San Luis Obispo

Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul

Master's Theses and Project Reports

This work investigates the feasibility of producing small scale, low aerodynamic loading wind tunnel models, using FDM 3D printing methods, that are both structurally and aerodynamically representative in the wind tunnel. To verify the applicability of this approach, a 2.07% scale model of the NASA CRM was produced, whose wings were manufacturing using a Finite Deposition Modeling 3D printer. Experimental data was compared to numerical simulations to determine percent difference in wake distribution and wingtip deflection for multiple configurations.

Numerical simulation data taken in the form of CFD and FEA was used to validate data taken in the wind ...


Uncertainty Quantification Of Turbulence Model Closure Coefficients On Openfoam And Fluent For Mildly Separated Flows, Ike Witte 2017 Washington University in St Louis

Uncertainty Quantification Of Turbulence Model Closure Coefficients On Openfoam And Fluent For Mildly Separated Flows, Ike Witte

Engineering and Applied Science Theses & Dissertations

In this thesis, detailed uncertainty quantification studies focusing on the closure coefficients of eddy-viscosity turbulence models for several flows using two CFD solvers have been performed. Three eddy viscosity turbulence models considered are: the one-equation Spalart-Allmaras (SA) model, the two-equation Shear Stress Transport (SST) k-ω model, and the one-equation Wray-Agarwal (WA) model. OpenFOAM and ANSYS Fluent are used as flow solvers. Uncertainty quantification analyses are performed for subsonic flow over a flat plate, subsonic flow over a backward-facing step, and transonic flow past an axisymmetric bump. In the case of flat plate, coefficients of pressure, lift, drag, and skin friction ...


Aerodynamics And Shock Buffet Of A Transonic Airfoil In Ground Effect, Boshun Gao 2017 Washington University in St. Louis

Aerodynamics And Shock Buffet Of A Transonic Airfoil In Ground Effect, Boshun Gao

Engineering and Applied Science Theses & Dissertations

No abstract provided.


Design And Computational Fluid Dynamics Analysis Of An Idealized Modern Wingsuit, Maria E. Ferguson 2017 Washington University in St Louis

Design And Computational Fluid Dynamics Analysis Of An Idealized Modern Wingsuit, Maria E. Ferguson

Engineering and Applied Science Theses & Dissertations

The aerodynamics of a modern wingsuit has been the subject of very few detailed scientific studies to date. The prevailing design process remains the dangerous “sew and fly” method, in which designs are tested when they are first flown. This study utilizes Computational Fluid Dynamics (CFD) tools to analyze the flow field and aerodynamics of an idealized wingsuit, which is designed using Computer-Aided Design (CAD) modeling. The 3D CAD software Autodesk Inventor is used to create the wingsuit model, which is designed with a Gottingen 228 airfoil cross-section and a relatively large planform of aspect ratio 1.3. The commercial ...


Aerodynamics And Vortex Structures Of A Flapping Airfoil In Forward Flight In Proximity Of Ground, Hang Li 2017 Washington University in St. Louis

Aerodynamics And Vortex Structures Of A Flapping Airfoil In Forward Flight In Proximity Of Ground, Hang Li

Engineering and Applied Science Theses & Dissertations

The traditional flapping wing high lift mechanism research mainly focuses on the wing in unbounded flow. However, the real insect flight includes not only the unbounded flow field but also the near-surface flight. Therefore, research on near-surface flight can help reveal the high-lift mechanism of insect flight and should also be beneficial to the research on Micro-Air-Vehicles (MAV). In this thesis, the flow fields of an airfoil in hover and forward flight are simulated in the presence of ground by newly available function of “dynamic meshing” in ANSYS Fluent is employed. The characteristics of aerodynamics, pressure distribution, and vortex structure ...


Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect, NING DENG 2017 Washington University in St. Louis

Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect, Ning Deng

Engineering and Applied Science Theses & Dissertations

The main focus of this thesis is on the simulation of flow past a three-dimensional wing-body configuration (DLR-F6) in ground effect; a complex 3D wing-body configuration in ground effect has never been analyzed in the aerodynamics literature to date. For the purpose of validation of the simulation approach, computations are performed for the DLR-F6 wing-body in unbounded flow and are compared with the experimental data. The commercial CFD solver ANSYS FLUENT is employed for computations. Compressible Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with Spalart-Allmaras (SA) and - Shear Stress Transport (SST) turbulence models are solved. The validated code is employed to ...


Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman 2017 International Islamic University - Malaysia

Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

This paper is an attempt to summarize the effect of wing tip devices employed by birds, as well as aeronautical engineers in the past to improve the performance characteristics of aircraft. The focus is on reduction of the induced drag or drag due to lift also known as inviscid drag. This paper will provide an insight on both biomimetic and conventional wing tip approaches to reduce the induced drag. Prior analysis and experiments on the aerodynamics of airplane performance due to both these separate studies have been discussed. The needs of the industry and their past inventions have been described ...


Application Of Strand-Cartesian Interfaced Solver On Flows Around Various Geometries, Yushi Yanagita 2017 Utah State University

Application Of Strand-Cartesian Interfaced Solver On Flows Around Various Geometries, Yushi Yanagita

All Graduate Plan B and other Reports

This work examines the application of a high-order numerical method to strand-based grids to solve the Navier-Stokes equations. Coined "Flux Correction", this method eliminates error terms in the fluxes of traditional second-order finite volume Galerkin methods. Flux Correction is first examined for applications to the Reynolds-Averaged Navier-Stokes equations to compute turbulent flows on a strictly strand-based domain. Flow over three geometries are examined to demonstrate the method’s capabilities: a three-dimensional bump, an infinite wing, and a hemisphere-cylinder configuration. Comparison to results obtained from established codes show that the turbulent Flux Correction scheme accurately predicts flow properties such as pressure ...


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