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NASA Supercritical Airfoils
NASA Technical Paper 2969 1990 NASA Supercritical Airfoils A Matrix of Family-Related Airfoils Charles D. Harris Langley Research Center Hampton, Virginia National Aeronautics-and Space Administration Office of Management Scientific and Technical Information Division Summary wind-tunnel testing. The process consisted of eval- A concerted effort within the National Aero- uating experimental pressure distributions at design and off-design conditions and physically altering the nautics and Space Administration (NASA) during airfoil profiles to yield the best drag characteristics the 1960's and 1970's was directed toward develop- over a range of experimental test conditions. ing practical two-dimensional turbulent airfoils with The insight gained and the design guidelines that good transonic behavior while retaining acceptable were recognized during these early phase 1 investiga- low-speed characteristics and focused on a concept tions, together with transonic, viscous, airfoil anal- referred to as the supercritical airfoil. This dis- ysis codes developed during the same time period, tinctive airfoil shape, based on the concept of local resulted in the design of a matrix of family-related supersonic flow with isentropic recompression, was supercritical airfoils (denoted by the SC(phase 2) characterized by a large leading-edge radius, reduced prefix). curvature over the middle region of the upper surface, and substantial aft camber. The purpose of this report is to summarize the This report summarizes the supercritical airfoil background of the NASA supercritical airfoil devel- development program in a chronological fashion, dis- opment, to discuss some of the airfoil design guide- lines, and to present coordinates of a matrix of cusses some of the design guidelines, and presents family-related supercritical airfoils with thicknesses coordinates of a matrix of family-related super- critical airfoils with thicknesses from 2 to 18 percent from 2 to 18 percent and design lift coefficients from and design lift coefficients from 0 to 1.0. -
University of Oklahoma Graduate College Design and Performance Evaluation of a Retractable Wingtip Vortex Reduction Device a Th
UNIVERSITY OF OKLAHOMA GRADUATE COLLEGE DESIGN AND PERFORMANCE EVALUATION OF A RETRACTABLE WINGTIP VORTEX REDUCTION DEVICE A THESIS SUBMITTED TO THE GRADUATE FACULTY In partial fulfillment of the requirements for the Degree of Master of Science Mechanical Engineering By Tausif Jamal Norman, OK 2019 DESIGN AND PERFORMANCE EVALUATION OF A RETRACTABLE WINGTIP VORTEX REDUCTION DEVICE A THESIS APPROVED FOR THE SCHOOL OF AEROSPACE AND MECHANICAL ENGINEERING BY THE COMMITTEE CONSISTING OF Dr. D. Keith Walters, Chair Dr. Hamidreza Shabgard Dr. Prakash Vedula ©Copyright by Tausif Jamal 2019 All Rights Reserved. ABSTRACT As an airfoil achieves lift, the pressure differential at the wingtips trigger the roll up of fluid which results in swirling wakes. This wake is characterized by the presence of strong rotating cylindrical vortices that can persist for miles. Since large aircrafts can generate strong vortices, airports require a minimum separation between two aircrafts to ensure safe take-off and landing. Recently, there have been considerable efforts to address the effects of wingtip vortices such as the categorization of expected wake turbulence for commercial aircrafts to optimize the wait times during take-off and landing. However, apart from the implementation of winglets, there has been little effort to address the issue of wingtip vortices via minimal changes to airfoil design. The primary objective of this study is to evaluate the performance of a newly proposed retractable wingtip vortex reduction device for commercial aircrafts. The proposed design consists of longitudinal slits placed in the streamwise direction near the wingtip to reduce the pressure differential between the pressure and the suction sides. -
Hydrofoil, Rudder, and Strut Design Issues
International Hydrofoil Society Correspondence Archives... Hydrofoil, Rudder, and Strut Design Issues (See also links to design texts and other technical information sources on the IHS Links Page) (Last Update: 11 Nov 03) Return to the Archived Messages Contents Page To search current messages, go to the Automated BBS Correspondence Where is Foil Design Data? [11 May 03] Where do I go for specifics about foil design? As in how do I determine the size, aspect ratio, need for winglets, shape, (inverted T vs. inverted Y vs. horizontal V), NASA foil specification . My plan calls for a single foil fully submerged with all control being accomplished with above water airfoils (pitch, roll, direction). Everything above water is conceptually set, but I have limited understanding / knowledge about foils. I understand that there are arrangements combining a lower speed and higher speed foil on the same vertical column, with some type of grooving on the higher speed foil to prevent cavitation at limited angles of attack. With respect to the website http://www.supramar.ch/ there is an article on grooving to avoid cavitation. I anticipate a limited wave surface (off shore wind) so elevation could be limited, and the initial lifting foil would be unlikely to be exposed to resubmersion at speed. Supramar is willing to guide/specify the grooving at no charge, but I need a foil design for their review or at least that seems to be the situation. I have not actually asked for a design proposal. Maybe I should. Actually it is hard to know if my request would even be taken seriously. -
Aviation Glossary
AVIATION GLOSSARY 100-hour inspection – A complete inspection of an aircraft operated for hire required after every 100 hours of operation. It is identical to an annual inspection but may be performed by any certified Airframe and Powerplant mechanic. Absolute altitude – The vertical distance of an aircraft above the terrain. AD - See Airworthiness Directive. ADC – See Air Data Computer. ADF - See Automatic Direction Finder. Adverse yaw - A flight condition in which the nose of an aircraft tends to turn away from the intended direction of turn. Aeronautical Information Manual (AIM) – A primary FAA publication whose purpose is to instruct airmen about operating in the National Airspace System of the U.S. A/FD – See Airport/Facility Directory. AHRS – See Attitude Heading Reference System. Ailerons – A primary flight control surface mounted on the trailing edge of an airplane wing, near the tip. AIM – See Aeronautical Information Manual. Air data computer (ADC) – The system that receives and processes pitot pressure, static pressure, and temperature to present precise information in the cockpit such as altitude, indicated airspeed, true airspeed, vertical speed, wind direction and velocity, and air temperature. Airfoil – Any surface designed to obtain a useful reaction, or lift, from air passing over it. Airmen’s Meteorological Information (AIRMET) - Issued to advise pilots of significant weather, but describes conditions with lower intensities than SIGMETs. AIRMET – See Airmen’s Meteorological Information. Airport/Facility Directory (A/FD) – An FAA publication containing information on all airports, seaplane bases and heliports open to the public as well as communications data, navigational facilities and some procedures and special notices. -
Aircraft Winglet Design
DEGREE PROJECT IN VEHICLE ENGINEERING, SECOND CYCLE, 15 CREDITS STOCKHOLM, SWEDEN 2020 Aircraft Winglet Design Increasing the aerodynamic efficiency of a wing HANLIN GONGZHANG ERIC AXTELIUS KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ENGINEERING SCIENCES 1 Abstract Aerodynamic drag can be decreased with respect to a wing’s geometry, and wingtip devices, so called winglets, play a vital role in wing design. The focus has been laid on studying the lift and drag forces generated by merging various winglet designs with a constrained aircraft wing. By using computational fluid dynamic (CFD) simulations alongside wind tunnel testing of scaled down 3D-printed models, one can evaluate such forces and determine each respective winglet’s contribution to the total lift and drag forces of the wing. At last, the efficiency of the wing was furtherly determined by evaluating its lift-to-drag ratios with the obtained lift and drag forces. The result from this study showed that the overall efficiency of the wing varied depending on the winglet design, with some designs noticeable more efficient than others according to the CFD-simulations. The shark fin-alike winglet was overall the most efficient design, followed shortly by the famous blended design found in many mid-sized airliners. The worst performing designs were surprisingly the fenced and spiroid designs, which had efficiencies on par with the wing without winglet. 2 Content Abstract 2 Introduction 4 Background 4 1.2 Purpose and structure of the thesis 4 1.3 Literature review 4 Method 9 2.1 Modelling -
Advanced RANS Modeling of Wingtip Vortex Flows
Center for Turbulence Research 73 Proceedings of the Summer Program 2006 Advanced RANS modeling of wingtip vortex flows By A. Revell , G. Iaccarino AND X. Wu y The numerical calculation of the trailing vortex shed from the wingtip of an aircraft has attracted significant attention in recent years. An accurate prediction of the flow over the wing is required to provide the correct initial conditions for the trailing vortex, while careful modeling is also necessary in order to account for the turbulence in the vortex core. As such, recent works have concluded that in order to achieve results of satisfac- tory accuracy, the use of complex turbulence modeling closures and numerical grids of considerable size is an absolute necessity. In Craft et al. (2006) it was proposed that a Reynolds stress-transport model (RSM) should be used, while Duraisamy & Iaccarino (2005) obtained optimal results with a version of the v2 f which was specifically sen- sitised to streamline curvature. The authors report grid requiremen− ts upward of 7 106 grid points, highlighting the substantial numerical cost involved with predicting this×flow. The computations here are reported for the flow over a NACA0012 half-wing with rounded wingtip at an incidence angle of 10◦, as measured by Chow et al. (1997). The primary aim is to assess the performance of a new turbulence modeling scheme which accounts for the stress-strain misalignment effects in a turbulent flow. This three-equation model bridges the gap between popular two equation eddy-viscosity models (EVM) and the seven equations of a RSM. Relative to a RSM, this new approach inherits the stability advantages of an eddy-viscosity scheme, together with a lower computational expense, and it has already been validated for a range of unsteady mean flows (Revell 2006). -
Influence of Aircraft Vortices on Spray Cloud
Journal of the American Mosquito Control Association, 12(2):372_379, 1996 Copyright O 1996 by the American Mosquito Control Association, Inc. INFLUENCE OF AIRCRAFT VORTICESON SPRAY CLOUD BEHAVIOR R. E. MICKLE Atmospheric Environment Service, 4905 Dufferin Street, Downsview, Ontario M3H5T4, Canada ABSTRACT. For small droplet spraying, the spray cloud is initially entrained into the wingtip vortices so that the ultimate fate of the spray is conffolled by the motion of these vortices. In close to 10O aerial sprays, the emitted spray cloud has been mapped using a scanning laser system that displays diffusion and transport of the spray cloud. Results detailing the concentrations within the spray cloud in space and time are given for sprays in parallel and crosswinds. Wind direction is seen to potentially alter the vortex motion and hence the fate of the spray cloud. In crosswind spraying, the vortex behavior associated with the 2 wings is found to differ, which leads to enhanced deposition from the upwind wing and enhanced drift from the downwind wins. INTRODUCTION EXPERIMENTAL METHODS The application of larvicides and adulticides The ARAL (AES Rapid Acquisition Lidar) by aircraft has been an effective mechanism for has been used in 2 experiments to map close to mosquito control. Howevet the benefits of 100 different spray scenarios in a variety of me- spraying are accompanied by the difficulty in teorological conditions (stable and unstable) en- targeting small droplets and by the potential en- compassing light to high winds at cross and par- vironmental impact of applying any chemical allel angles to the flight line. Aircraft used in into the environment in quantities that may be these studies have included a Cessna 188, TBM toxic to nontarget species. -
Design and Computational Analysis of Winglets
Turkish Journal of Computer and Mathematics Education Vol.12 No.7 (2021), 1-9 Research Article Design and Computational Analysis of Winglets V.Madhanraj(1), Kaka Ganesh Chandra(2), Desineni Swprazeeth(3) , Battina Dhanush Gopal(4), Hindustan Institute of Technology and Science, Padur, Chennai. Article History: Received: 10 January 2021; Revised: 12 February 2021; Accepted: 27 March 2021; Published online: 16 April 2021 Abstract: The primary goal of this project is to learn and analyse the aerodynamic performance of wings and various types of winglets and wingtip devices. The objective of this study is to improve a model for various types of winglets and wingtip devices using the software SOLIDWORKS, And Fluent Analysis using the software ANSYS. The best performing aerofoil in terms of aerodynamic efficiency, NACA 64-215, was chosen for wing construction. A wing which is without winglets was simulated, followed by a wing with various winglets at different Cant angles. To determine the aerodynamic efficiency, a wing with a blended winglet and a raked winglet was simulated. In order to found a more efficient wing with winglets, designs of Blended and Raked winglets are modified, and comparison of the performance of winglets by varying with different cant angles, 30° and 60° were performed. As a result of this work, it was concluded that adding a winglet to a wing increases its aerodynamic efficiency in terms of CL/CD. Keywords: Winglets, Wingtip Devices, Blended Winglet, Raked Winglet, Lift, Drag, Vorticity, Co-efficient of Lift, Co- efficient of Drag 1.1 Introduction to Winglets Current global environmental issues such as rising aviation fuel costs and global warming have forced airlines to make adjustments. -
Human Powered Hydrofoil Design & Analytic Wing Optimization
Human Powered Hydrofoil Design & Analytic Wing Optimization Andy Gunkler and Dr. C. Mark Archibald Grove City College Grove City, PA 16127 Email: [email protected] Abstract – Human powered hydrofoil watercraft can have marked performance advantages over displacement-hull craft, but pose significant engineering challenges. The focus of this hydrofoil independent research project was two-fold. First of all, a general vehicle configuration was developed. Secondly, a thorough optimization process was developed for designing lifting foils that are highly efficient over a wide range of speeds. Given a well-defined set of design specifications, such as vehicle weight and desired top speed, an optimal horizontal, non-surface- piercing wing can be engineered. Design variables include foil span, area, planform shape, and airfoil cross section. The optimization begins with analytical expressions of hydrodynamic characteristics such as lift, profile drag, induced drag, surface wave drag, and interference drag. Research of optimization processes developed in the past illuminated instances in which coefficients of lift and drag were assumed to be constant. These shortcuts, made presumably for the sake of simplicity, lead to grossly erroneous regions of calculated drag. The optimization process developed for this study more accurately computes profile drag forces by making use of a variable coefficient of drag which, was found to be a function of the characteristic Reynolds number, required coefficient of lift, and airfoil section. At the desired cruising speed, total drag is minimized while lift is maximized. Next, a strength and rigidity analysis of the foil eliminates designs for which the hydrodynamic parameters produce structurally unsound wings. Incorporating constraints on minimum takeoff speed and power required to stay foil-borne isolates a set of optimized design parameters. -
Wingtip Vortices and Free Shear Layer Interaction in The
WINGTIP VORTICES AND FREE SHEAR LAYER INTERACTION IN THE VICINITY OF MAXIMUM LIFT TO DRAG RATIO LIFT CONDITION Dissertation Submitted to The School of Engineering of the UNIVERSITY OF DAYTON In Partial Fulfillment of the Requirements for The Degree of Doctor of Philosophy in Engineering By Muhammad Omar Memon, M.S. UNIVERSITY OF DAYTON Dayton, Ohio May, 2017 WINGTIP VORTICES AND FREE SHEAR LAYER INTERACTION IN THE VICINITY OF MAXIMUM LIFT TO DRAG RATIO LIFT CONDITION Name: Memon, Muhammad Omar APPROVED BY: _______________________ _______________________ Aaron Altman Markus Rumpfkeil Advisory Committee Chairman Committee Member Professor; Director, Graduate Aerospace Program Associate Professor Mechanical and Aerospace Engineering Mechanical and Aerospace Engineering _______________________ _______________________ Jose Camberos Wiebke S. Diestelkamp Committee Member Committee Member Adjunct Professor Professor & Chair Mechanical and Aerospace Engineering Department of Mathematics _______________________ _______________________ Robert J. Wilkens, PhD., P.E. Eddy M. Rojas, PhD., M.A., P.E. Associate Dean for Research and Innovation Dean, School of Engineering Professor School of Engineering ii © Copyright by Muhammad Omar Memon All rights reserved 2017 iii ABSTRACT WINGTIP VORTICES AND FREE SHEAR LAYER INTERACTION IN THE VICINITY OF MAXIMUM LIFT TO DRAG RATIO LIFT CONDITION Name: Memon, Muhammad Omar University of Dayton Advisor: Dr. Aaron Altman Cost-effective air-travel is something everyone wishes for when it comes to booking flights. The continued and projected increase in commercial air travel advocates for energy efficient airplanes, reduced carbon footprint, and a strong need to accommodate more airplanes into airports. All of these needs are directly affected by the magnitudes of drag these aircraft experience and the nature of their wingtip vortex. -
Design of a Foiling Optimist
Journal of Sailboat Technology, Article 2018-06 © 2018, The Society of Naval Architects and Marine Engineers. DESIGN OF A FOILING OPTIMIST A. Andersson, A. Barreng, E. Bohnsack, L. Larsson, L. Lundin, G. Olander, R. Sahlberg and E. Werner Chalmers University of Technology, Sweden C. Finnsgård and A. Persson Chalmers University of Technology and SSPA Sweden AB, Sweden M. Brown and J McVeagh SSPA Sweden AB, Sweden Downloaded from http://onepetro.org/jst/article-pdf/3/01/1/2205397/sname-jst-2018-06.pdf by guest on 26 September 2021 Manuscript received January 16, 2018; accepted September 11, 2018. Abstract: Because of the successful application of hydrofoils on the America's Cup catamarans in the past two campaigns the interest in foiling sailing craft has boosted. Foils have been fitted to a large number of yachts with great success, ranging from dinghies to ocean racers. An interesting question is whether one of the slowest racing boats in the world, the Optimist dinghy, can foil, and if so, at what minimum wind speed. The present paper presents a comprehensive design campaign to answer the two questions. The campaign includes a newly developed Velocity Prediction Program (VPP) for foiling/non-foiling conditions, a wind tunnel test of sail aerodynamics, a towing tank test of hull hydrodynamics and a large number of numerical predictions of foil characteristics. An optimum foil configuration is developed and towing tank tested with satisfactory results. The final proof of the concept is a successful on the water test with stable foiling -
Modelling Flow Around a NACA 0012 Foil a Report for 3Rd Year, 2Nd Semester Project
Modelling Flow around a NACA 0012 foil A report for 3rd Year, 2nd Semester Project Eamonn Colley [email protected] Supervisor: Tim Gourlay Co‐Supervisor: Andrew King October 2011 Curtin University Perth, Western Australia 1 Abstract The third year project consisted of using open source software (OpenFoam) to model 2D foils – in particular the NACA 0012. It was found that although the flow seemed to simulate what should be happening around the foil, the results did not agree with test programs and approximate theoretical values. Using X‐Foil, a small program that uses a panel method to find the lift, drag and pressure distribution by a boundary layer evaluation algorithm we could compare the results obtained from OpenFOAM. It was determined that the discrepancies in the lift coefficient, drag coefficient and pressure coefficient could be due the mesh not accurate enough around the leading and trailing edge or that unrealistic values were used. This can be improved by refining the mesh around these areas or changing the values to be close matching to a full size helicopter. Experimental work was also completed on a 65‐009 NACA foil. Although the data collected from this experiment could not be used to compare any results made in OpenFOAM, the techniques learnt could be applied to future experiments to improve the quality of data taken. 2 Contents Modelling Flow around a NACA 0012 foil...............................................................................................1 Abstract...................................................................................................................................................2