Aerodynamics and Fluid Mechanics Commons^™

Analysis Of One Way Valve Mechanism For Wings Of A Flapping Drone, Xinchen Deng

Student Works (2020-2029)

The flapping drone is one type of MAVs which is defined as a miniature unmanned aerial vehicle that is inspired by flying birds and insects. Flapping wings can make a perfect combination of thrust and lift by flapping up and down with full usage of unsteady air. The flapping drone has the advantages of high maneuverability and a special lift generation mechanism. Compared with rotary-wing or fixed-wing MAV, it is smaller, lighter, and has higher flight performance. It can quickly change the flight direction and flight speed by control the flapping frequency and it is the only flight mode that …

Numerical Investigation Of Leading-Edge Modifications Of A Naca Airfoil, Anisur Rahman Ikram

Masters Theses

A parametric investigation was carried out to understand the flow characteristics of tubercle airfoils and to determine the best approach and parameters for designing a tubercle airfoil. For this purpose, a straight edge base airfoil (NACA 4414) and several tubercle airfoils, by modifying the leading edge of the base airfoil, were created in SolidWorks and tested with Computational Fluid Dynamics (CFD) application software Star CCM+.

Alternative tubercle airfoil with elliptical bumps demonstrated superior post-stall performance when compared to their straight edge counterparts; their post-stall lift did not decrease drastically. However, their pre-stall lift coefficients were always lower than the base …

Lip Thrust Apparatus, Ian M. Wilson, Alvin K. Cheong

Mechanical Engineering

This document contains the background information, defined scope of work, preliminary design philosophy, conceptual design development, and final design choices along with its corresponding manufacturing and design verification plans. It also includes the preliminary testing and prototyping necessary in bringing our verification prototype to its final configuration for delivery. Finally, it includes the entire manufacturing process followed in creating the final project and the extensive testing performed to ensure it meets the defined engineering specifications. The aerodynamic phenomenon being analyzed and demonstrated in our final deliverable can be seen in a scenario where when a propeller is enclosed in a …

Design, Construction And Testing Of A 3-Component Force Balance For Educational Wind Tunnels In Undergraduate Aerodynamics, Milan Tomin, Marco Scipioni, Benjamin Gatti

Journal of Aviation/Aerospace Education & Research

This article is focused on providing detailed instructions on how to build and use a force balance for educational wind tunnels. The article’s objective is to encourage undergraduate students in underfunded programs to engage in the field of aerodynamics. The discussed force balance represents an affordable device that only requires basic components like Arduino board, a servo motor, and acrylic and aluminum as construction materials. A simple data collection example is included at the end of the article showing that this simple force balance can collect meaningful data about lift, drag, and moment coefficient of a tested airfoil.

Fuel Flow Reduction Impact Analysis Of Drag Reducing Film Applied To Aircraft Wings, Damon Resnick, Chris Donlan, Nimish Sakalle, Cody Pinkerman

SMU Data Science Review

In this paper, we present an analysis of flight data in order to determine whether the application of the Edge Aerodynamix Conformal Vortex Generator (CVG), applied to the wings of aircraft, reduces fuel flow during cruising conditions of flight. The CVG is a special treatment and film applied to the wings of an aircraft to protect the wings and reduce the non-laminar flow of air around the wings during flight. It is thought that by reducing the non-laminar flow or vortices around and directly behind the wings that an aircraft will move more smoothly through the air and provide a …

Study Of Biomimetic Micro And Macro Structures For Drag Reduction, Justin S. Schrout

Graduate Theses, Dissertations, and Problem Reports (ETD)

The ever increasing demand for global travel coupled with increasing costs of fuels have prompted many researchers to study new methods to save fuel to make travel more efficient. One of the proverbial low-hanging fruits for fuel efficiency is aerodynamic drag reduction. Simple changes in the shape or placement of structures on the surface of different types of vehicles have been shown to increase fuel efficiency by reducing drag (e.g., add-on lower and aft wake fairings on tractor trailers which have seen a tremendous rise in popularity on US highways in recent years). Areas of interest in drag reduction have …

Surface Structure And Its Effect On Reducing Drag, Ragini Ramachandran

Doctoral Dissertations and Master's Theses

A miniature subsonic open return wind tunnel was designed and fabricated to measure drag on small test models at low Reynolds numbers. The wind tunnel featured a sensitive strain gauge type load cell. The average drag coefficient of sphere and cube test models were used to validate the miniature wind tunnel, and the values obtained were consistent with published results over the range of Reynolds numbers tested. These initial results gave confidence that the tunnel could be used to study the effects of surface finish on the drag of various models. Several fabrics with differing ribbed surface structures, including a …

Design Advantages Of Skin Friction Drag Reduction Using Riblets, John Michael Gregory

Mechanical & Aerospace Engineering Theses & Dissertations

The research reported here has examined the potential improvements in overall aircraft performance that can result from integrating skin friction reduction technology, such as riblets, early in the aircraft design cycle. This study has shown that riblets can improve the payload capacity, increase the range, and improve performance of transport aircraft. If recent advances in fabrication techniques make it possible to create aluminum wing surfaces with integral riblet geometries, the applications could be widespread and the gains significant.

Boundary Layer Measurements Related To Wind Tunnel Testing Of Riblets, Emrah Cinar

Mechanical & Aerospace Engineering Theses & Dissertations

With fuel economy being a significant factor in today's world of aviation, aircraft manufacturers have been looking into ways to decrease drag to save fuel. Drag reduction using riblets on wing and fuselage surfaces is . an area that has been studied extensively for the last two decades. In preparation for a larger project which will use several methods to simulate this phenomena, small scale research had to be done to find ways to generate similar conditions on scaled models in a low speed wind tunnel and examine boundary layer behavior.

In this project, boundary layer measurement techniques, such as …

Aerodynamic And Acoustic Investigations Of An Advanced Over-The-Wing Nacelle Transport Aircraft Configuration, Geoffrey A. Hill

Mechanical & Aerospace Engineering Theses & Dissertations

The transonic aerodynamic and low-speed acoustic characteristics of an advanced, Over-the-Wing Nacelle (OWN), subsonic transport configuration are assessed. The cruise aerodynamics of the OWN were analyzed using both inviscid Euler and viscous Navier-Stokes CFD. Results of the assessments are compared to a similar configuration with a more traditional Under-the-Wing Nacelle (UWN) installation and a similar reference Wing-Body Qualitative observations and quantitative drag computations are made for the three configurations at a cruise Mach number of0.78, an approximate altitude of35,000-ft, and a C_L, of 0.44. It was found that the OWN's novel inboard wing channel design is effective in …

Aerodynamic Gradient-Based Optimization Using Computational Fluid Dynamics And Discrete Sensitivities For Practical Problems, Mohagna Jayendrarai Pandya

Mechanical & Aerospace Engineering Theses & Dissertations

A gradient-based shape optimization methodology based on quasi-analytical sensitivities has been developed for practical three-dimensional aerodynamic applications. The flow analysis has been rendered by a fully implicit, finite-volume formulation of the Euler and Thin Layer Navier-Stokes (TLNS) equations. The flow equations and aerodynamic sensitivity equation have been solved using an alternating-direction-implicit (ADI) algorithm for memory efficiency. A wing geometry model based on space-surface and planform parameterization has been utilized. The present methodology and its components have been tested via several comparisons.

Initially, the inviscid flow analysis for a wing has been compared with those obtained using an unfactored, Preconditioned Conjugate …

Effect Of Passive Flow-Control Devices On The Drug Of A Tractor-Trailer Model, Jagjit K. Ahuja

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic drag of tractor trailers is responsible for approximately half of the fuel consumption at highway speeds (55m.p.h.). Thus, it is important that vehicle drag be reduced in order to reduce operating costs and to conserve fuel. The purpose of the subject research conducted in the Old Dominion University Low-Speed Wind Tunnel was to determine the effect of various add-on flow-control devices, such as a cab-mounted flow deflector and gap seals between the tractor and the trailer. In addition, the effect of trailer rear-edge shaping has been studied. This was accomplished by contouring the trailer's rear end. It has …