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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 ...


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 ...


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 ...


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 ...


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 ...


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 ...


Enceladus Sample Return Mission, Braxton Brakefield, Rekesh Ali, Andrew Bishop, Shelby Honaker, David Taylor 2017 University of Tennessee, Knoxville

Enceladus Sample Return Mission, Braxton Brakefield, Rekesh Ali, Andrew Bishop, Shelby Honaker, David Taylor

University of Tennessee Honors Thesis Projects

No abstract provided.


In-House Fabrication Of Temperature Sensitive Paint For Turbine Cooling Research, Mayur D. Patel, Mark A. Ricklick 2017 Embry-Riddle Aeronautical University

In-House Fabrication Of Temperature Sensitive Paint For Turbine Cooling Research, Mayur D. Patel, Mark A. Ricklick

Beyond: Undergraduate Research Journal

The Temperature Sensitive Paint (TSP) is a widely used method in measuring and visualizing flow separation and heat transfer. Compared to the cost and time consumption needed for methods such as pitot tubes, temperature sensitive paint is a cheaper alternative. Due to high usage in College of Engineering research projects, it was determined that in house fabrication of temperature sensitive paint would reduce time and cost limitations. For initial stages, literature research was performed to determine the recipe of intensity based TSP with luminophore and polymer binder that operated optimum at temperatures from 0-100°C. Europium III thenoyltrifluoroacetonate was determined ...


An Archival Analysis Of Stall Warning System Effectiveness During Airborne Icing Encounters, John Michael Maris 2017 Embry-Riddle Aeronautical University

An Archival Analysis Of Stall Warning System Effectiveness During Airborne Icing Encounters, John Michael Maris

Dissertations and Theses

An archival study was conducted to determine the influence of stall warning system performance on aircrew decision-making outcomes during airborne icing encounters. A Conservative Icing Response Bias (CIRB) model was developed to explain the historical variability in aircrew performance in the face of airframe icing. The model combined Bayes’ Theorem with Signal Detection Theory (SDT) concepts to yield testable predictions that were evaluated using a Binary Logistic Regression (BLR) multivariate technique applied to two archives: the NASA Aviation Safety Reporting System (ASRS) incident database, and the National Transportation Safety Board (NTSB) accident databases, both covering the period January 1, 1988 ...


Study Of Experimentally Blended Wings, Ray Roos 2894888 2017 The University of Akron

Study Of Experimentally Blended Wings, Ray Roos 2894888

Honors Research Projects

This aim of this senior design project is to investigate the combination of a Selig 1223 and FX 74-CL5-140 into one profile to increase lift without significantly increasing drag. Our project began with researching current solutions for high lift and low drag airfoils. We found two airfoils which would be the target of our research, a Selig 1223 and the FX 74-CL5-140. After learning about the Cl and Cd of the current airfoils we built and physically tested the airfoils using additive manufacturing. A pressure differential tunnel was used to validate the airfoils. After researching how to blend two airfoil ...


Design And Modeling Of A Heat Exchanger For Porous Combustor Powered Steam Generators In Automotive Industry, Apratim Dasgupta 2017 University of Central Florida

Design And Modeling Of A Heat Exchanger For Porous Combustor Powered Steam Generators In Automotive Industry, Apratim Dasgupta

Electronic Theses and Dissertations

A major challenge faced by automobile manufacturers is to achieve reduction of particulate emission to acceptable standards, as the emission standards become more and more stringent. One of the ecologically friendly options to reduce emissions is to develop external combustion in a steam engine as a replacement of the internal combustion engine. There are multiple factors, other than pollution that need to be considered for developing a substitute for Internal Combustion Engine, like specific power, throttle response, torque speed curve, fuel consumption and refueling infrastructure. External combustion in a steam engine seems to be a bright idea, for a cleaner ...


Dynamic Load And Response Prediction Of Hawt Blades For Health Monitoring Application, Heather Sauder, Partha Sarkar, Simon Laflamme 2016 Iowa State University

Dynamic Load And Response Prediction Of Hawt Blades For Health Monitoring Application, Heather Sauder, Partha Sarkar, Simon Laflamme

Simon Laflamme

Wind turbine blades of a Horizontal Axis Wind Turbine (HAWT) are prone to damage; some insurance agencies report that as much as 40% of all claims are from blade damage. While most claims are not very expensive in comparison to other HAWT component repairs, for example, repairing of the gel coat, others, like replacing the entire blade can be one of the most expensive tasks. As the world moves toward larger and longer blades to capture more wind energy this problem will continue to grow. Inspecting wind turbine blades presents a challenge with most techniques requiring a technician to repel ...


Effect Of Slot Span On Wing Performance, Juan F. Granizo 2016 Embry-Riddle Aeronautical University

Effect Of Slot Span On Wing Performance, Juan F. Granizo

Dissertations and Theses

This report presents new numerically-derived correlations to estimate the aerodynamic properties of a three-dimensional wing that features a partial to full span fixed slot. Fixed slots have been thoroughly studied in the past with regards to their operation and the relation between slot geometry and wing performance. There have also been many studies on the advantages and disadvantages of tip-slotted wings and the comparison between these and full-slotted wings. Up to this point however, a study on the effects of slot span on wing performance has not been performed. Effect of slot span on wing performance is evaluated in an ...


Effect Of Flow-Acoustic Resonant Interactions On Aerodynamic Response Of Transitional Airfoils, Joseph Hayden 2016 Embry-Riddle Aeronautical University

Effect Of Flow-Acoustic Resonant Interactions On Aerodynamic Response Of Transitional Airfoils, Joseph Hayden

Dissertations and Theses

A high-accuracy numerical study is conducted to examine the impact of flow-acoustic resonant interactions on the aerodynamic response of symmetric and cambered airfoils in the realistic transitional flow regimes with Rec=140,000 and M=0.0465 as well as the low Reynolds number flow regime with Rec=10,000 and M=0.2. The symmetric NACA-0012 and the cambered SD7003 airfoils are investigated at various angles of attack that have been found previously to include both the tone and no-tone producing regimes, with specific focus on the aerodynamic lift response. Additional simulations are conducted with a low-intensity synthetic turbulence ...


Assessment Of Asymmetric Flight On Solar Uas, Eric Belfield 2016 California Polytechnic State University, San Luis Obispo

Assessment Of Asymmetric Flight On Solar Uas, Eric Belfield

Master's Theses and Project Reports

An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on ...


The Design And Computational Validation Of A Mach 3 Wind Tunnel Nozzle Contour, Sarah Elizabeth Adams 2016 University of Tennessee, Knoxville

The Design And Computational Validation Of A Mach 3 Wind Tunnel Nozzle Contour, Sarah Elizabeth Adams

Masters Theses

The objective of this effort was to design and validate a Mach 3 wind tunnel nozzle contour. The nozzle will be used for an existing facility, replacing a Mach 2.3 nozzle. The nozzle contour was design using the widely-distributed CONTUR code developed by Sivells. The program uses a combination of analytical solutions and the method of characteristics in order to calculate a nozzle contour. A nozzle contour adhering to the existing geometry requirements was achieved through an iterative process. The flowfield of the finalized nozzle contour was solved using ANSYS fluent. The solution results were analyzed for flow uniformity.


Dji S-1000 Spreading Wings Octocopter: Determination Of Rotor Downwash Slipstream Size, Jonathan Lemieux 2016 University of Tennessee, Knoxville

Dji S-1000 Spreading Wings Octocopter: Determination Of Rotor Downwash Slipstream Size, Jonathan Lemieux

Masters Theses

The DJI S-1000 Spreading Wings octocopter rotor downwash slipstream area of influence was measured in axial climb conditions and in straight level flight. These data were gathered using a simple apparatus of distributed anemometers and a custom made boom affixed to the drone. Straight level flight tests incurred autopilot oscillations that rendered the data gathering and analysis challenging. The best quality data was acquired during the axial climb flight tests. The axial climbs were conducted in calm winds. It was determined that the axial climbs under these conditions displaced the rotor slipstream 9 ± 2.5 cm to the rear of ...


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