Technical Soaring最新文献

Flight is Not Improbable: Octave Chanute Combines Civil Engineering With Aeronautics 飞行并非不可能:将土木工程与航空学相结合

Technical Soaring Pub Date : 2015-01-05 DOI: 10.2514/6.2015-0105

Simine Short

引用次数: 0

Fly around the World with a Solar Powered Airplane 驾驶太阳能飞机环游世界

Technical Soaring Pub Date : 2008-09-14 DOI: 10.2514/6.2008-8954

Hannes Ross

{"title":"Fly around the World with a Solar Powered Airplane","authors":"Hannes Ross","doi":"10.2514/6.2008-8954","DOIUrl":"https://doi.org/10.2514/6.2008-8954","url":null,"abstract":"Quite a few manned and unmanned solar powered aircraft have been developed and flown in the last 30 years. Objectives and missions cover a wide spectrum ranging from a pure technological goal to “Fly with Solar Energy” to civil or military surveillance and reconnaissance missions. However, none of those aircraft was able to demonstrate a continuous day and night operation until 2005. An overview of the historic solar powered aircraft is provided and the basic challenges which have to be solved for a solar powered aircraft are being discussed: • Geographical area of operation, time windows during the year, mission profiles, payload • Energy collection and utilization • Typical design parameter for different missions Today’s technological status in the critical areas (solar cells, batteries, structure/materials) is discussed. It allows developing a solar powered aircraft with the capability not only to fly during the sunshine hours, but to save enough energy during the day to fly throughout the night and recollect energy after sunrise the next day for a perpetual continuation of flight. In 2001 the Swiss Bertrand Piccard, who together with Brian Jones (UK) circled the earth in a balloon in 1999, proposed to design a manned solar powered aircraft and to fly it around the world. Such an aircraft is now being developed by the Solar Impulse organization in Switzerland. The primary objective of this endeavor is to make people aware of the fact, that the conventional energy sources are limited and that renewable energy must and can be used to solve future demands. Development aspects of the Solar Impulse Program are described and a program status is provided. 1. Solar Power Collection, the Basics Today solar cells for power generation on houses have an efficiency of up to 17 %. For special purposes monocrystaline cells may convert more than 20 % of the incoming energy into electric energy. The trivial, however, for flying extremely important conclusion is: the electric energy collected is proportional to the solar cell area (Fig. 1-1). Energy (W) Collected Solar Cell Area (m2) Theoretical Limit of SC efficiency: ~28 %, monocristaline Silizium ~29 % Gallium Arsenid 20% for high tech application ~14 % for ground based systems (e.g.solar roof ) Energy collected is proportional to solar cell area! Solar Cell Cost Fig. 1-1: Solar energy collection The orientation and the inclination of the solar cell area relative to the horizon are very important parameters, in addition to the geographic location (latitude), the time of the year and the time of the day. Also the altitude and of course the weather (clouds, humidity, temperature) play an important role for the determination of the solar energy collection. Fig.1-2 illustrates these principal relationships and shows calculated and measured values for solar energy collected for a location near Munich (Germany) on a summer and winter day [Ref.1]. A maximum of 900W of beam energy can be collected with an area of 1 ","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"333 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122990106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 55

Wind Energy Extraction by Birds and Flight Vehicles 利用鸟类和飞行器提取风能

Technical Soaring Pub Date : 2005-01-10 DOI: 10.2514/6.2005-241

P. Lissaman

{"title":"Wind Energy Extraction by Birds and Flight Vehicles","authors":"P. Lissaman","doi":"10.2514/6.2005-241","DOIUrl":"https://doi.org/10.2514/6.2005-241","url":null,"abstract":"When a bird or flight vehicle is oriented with a component of its lift vector aligned with the natural wind work is done on the flight system. Consequently, by suitable maneuvers, variations in wind speed can be used to add energy to the system. These procedures are used by albatrosses and many other birds. The equations of motion are simplified by normalizing using the minimum drag speed and integrating numerically for the control cycles involving angles of attack and bank. An energy neutral cycle by which an un-powered vehicle returns to initial velocity and height depends only upon the maximum lift/drag ratio of the vehicle and the wind speed variation. The minimum speed difference for a neutral energy cycle occurs for a vertical or horizontal step in wind speed. For a continuous wind profile a variational method is used to find the minimum gradient for a neutral energy cycle. Simple expressions are derived for the minimum wind variations for these two cases. The oceanic boundary layer and the shear layer downwind of a ridge are studied, and neutral energy wind criteria derived for them. Birds and small UAVs, with flight speeds comparable to atmospheric wind variations, can profit from wind energy extraction. Presented at the 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno NV, January, 10-13, 2005: Lissaman, P.B.S., “Wind Energy Extraction by Birds and Flight Vehicles,” AIAA Paper 2005-241, AIAA Annual Meeting, Reno, Jan. 2005.","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"69 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114121197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 80

Flight Path Optimization for Competition Sailplanes through State Variables Parameterization 基于状态变量参数化的竞赛滑翔机航迹优化

Technical Soaring Pub Date : 2004-11-16 DOI: 10.4271/2004-01-3472

P. H. I. A. D. Oliveira, R. D. F. Pinto

引用次数: 1

The Influence of Materials on the Development of Sailplane Design 材料对滑翔机设计发展的影响

Technical Soaring Pub Date : 2003-07-14 DOI: 10.2514/6.2003-2778

C. Kensche

{"title":"The Influence of Materials on the Development of Sailplane Design","authors":"C. Kensche","doi":"10.2514/6.2003-2778","DOIUrl":"https://doi.org/10.2514/6.2003-2778","url":null,"abstract":"The evolution of sailplanes in the past century is a product of both the progress in aerodynamics as well as the usage of new materials including constructive and technological solutions. The focus of this contribution is to highlight the importance of new materials and their application in the development of sailplane design. Three periods are classified. The first beginning with the flights of O. Lilienthal in 1891 is characterized by wire braced, cloth covered willow, bamboo and wood constructions of the wings with thin airfoils. New possibilities were discovered in 1921 with the Vampyr where by means of plywood a cantilever single beam design including a D-tube leading edge of high torsion stiffness allowed a thick airfoil wing without wire braces. In this period also some important metal designs can be found. The end of this period which culminated in the HKS and KA6 constructions was rung in with the Phoenix in 1957 which was completely designed in glass fiber reinforced plastics (GFRP). The introduction of high strength and high modulus carbon fibers finally enabled further possibilities to increase the glider per-formance. Composite materials have been dominating the development of sailplanes now for nearly 50 years. Nevertheless, there are still problems to be solved such as the missing confidence in the very good fatigue properties of FRP. Thus, also lifetime certification and evaluation items are discussed, too.","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115894205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

The Rebirth of Hang Gliding and Ultralight Sport Aviation 悬挂式滑翔和超轻型运动航空的重生

Technical Soaring Pub Date : 2003-07-14 DOI: 10.2514/6.2003-2876

Paul W. Dees

{"title":"The Rebirth of Hang Gliding and Ultralight Sport Aviation","authors":"Paul W. Dees","doi":"10.2514/6.2003-2876","DOIUrl":"https://doi.org/10.2514/6.2003-2876","url":null,"abstract":"Ultralight aircraft provide thousands of participants an inexpensive avenue to fly recreationally. The aircraft are manufactured in a viable industry using technology developed to optimize performance at low cost. Many pioneering aircraft of the 1890-1930 timeframe were hang gliders and ultralight aircraft. Examples include the hang gliders of Otto Lilienthal and Octave Chanute, the famous gliders of the Wright brothers, and Santos Dumont's famous Demoisille ultralight airplane of 1909. Powered flight rapidly evolved into heaviel faster, and more sophisticated aircraft to serve the multitude of military and commercial roles they do today. In the early 1970's a rebirth of sorts occurred with the adaptation of Francis Rogallo's flexible wing into a viable weight-shift controlled hang glider. These \"Standard Rogallo\" wings offered recreational flight to an ordinary person at an affordable price, though with some dangerous flight characteristics. Hang gliding as a sport evolved rapidly during ttire 1970's and 1980's with the advent of better, safer gliders and improved pilot skills. In the USA, the FAA allowed self-regulation by not requiring licensing of pilots or certification of gliders. The United States Hang Gliding Association (USHGA) standardizes training, rates pilots, and promotes the sport. Hang gliders are currently certified privately through limited testing to Hang Glider Manufacturing Association (HGMA) standards. In the mid 1970's pilots began adding small two-cycle engines to hang gliders, and the rebirth of ultralight aviation began in earnest. A burst of creativity resulted in many new designs, many with dangerous flight characteristics. Several groups offered training and certification of pilots. Safer designs evolved into several basic types, including conventional looking designs, trikes, and powered parachutes. Paragliding began during the 1980's with the advent of foot-launched gliding parachut-like aircraft. Powered paragliders soon followed. Likewise, several footlaunched sailplane designs also evolved during the 1980's, and ultralight sailplanes have emerged as another new exciting sport aviation discipline. Current hang gliding technology includes rigid winged designs offering greatly improved performance.","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123989309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

EVOLUTION OF AIRFOILS FOR SAILPLANES 滑翔机翼型的演变

Technical Soaring Pub Date : 2003-07-14 DOI: 10.2514/6.2003-2779

K. Horstmann, L. Boermans

{"title":"EVOLUTION OF AIRFOILS FOR SAILPLANES","authors":"K. Horstmann, L. Boermans","doi":"10.2514/6.2003-2779","DOIUrl":"https://doi.org/10.2514/6.2003-2779","url":null,"abstract":"About 110 years ago O. Lilienthal built his gliders with cambered plate wings which were stiffened out by a plenty of strut wires. Analysis of this type of airfoils show their narrow range of angles of attack and their rapid loss of lift at stall conditions. The development of the thick airfoils of the Gottingen series led to the construction of the Vampyr with a strut free wing and a torsion leading edge box. The quality of the surface and the maximum thickness close to the leading edge did not allow reasonable extent of laminar flow. The big advantages of laminar flow airfoils have been discovered in the late thirties and have been systematically investigated by the NACA. But only the combination of an airfoil designed for laminar flow and the excellent surface quality of a sandwich construction of glass fibre reinforced plastics and solid foam made the big success of laminar airfoils for sailplanes possible. This is shown by way of the example of the Ka 6 and the Phonix. Examples of typical airfoils demonstrate further developments: Airfoils without and with flaps; problem of laminar separation bubbles, use of destabilisation zones and use of turbulators. An attempt to assess future possibilities for performance improvements of sailplanes closed the paper.","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116156501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

THE EVOLUTION OF SAILPLANE WING DESIGN 滑翔机机翼设计的演变

Technical Soaring Pub Date : 2003-07-14 DOI: 10.2514/6.2003-2777

M. Maughmer

{"title":"THE EVOLUTION OF SAILPLANE WING DESIGN","authors":"M. Maughmer","doi":"10.2514/6.2003-2777","DOIUrl":"https://doi.org/10.2514/6.2003-2777","url":null,"abstract":"As the sport of soaring initially focused on exploiting ridge winds to maintain altitude, and the level of structural technology was unable to allow large spans, the low sink rates required were achieved by wings having large areas and fairly low aspect ratios. By the late 1920's, the discovery of thermals led to the use of climb/glide sequences for cross-country soaring. Thus, the trade-off between low induced drag for climb and low profile drag for cruise became a critical issue in the design of sailplane wings. Theoretical guidance for these designs was provided primarily by the lifting-line theory of Ludwig Prandtl and the minimum induced drag, elliptical loading result of Max Munk. During this time, the need for greater spans and higher aspect ratios led to structural advancements in the primarily wooden airframes and the development of some very interesting wing geometries, such as the distinctive gull wings that were then popular. The evolution of wing design through this period continued slowly until the introduction of new materials and laminar flow wing sections led to very rapid advancements beginning in the late 1950's. The use of glass-reinforced plastic structures, and later carbon-reinforced plastic, allowed designers to incorporate much larger aspect ratios than had been possible earlier. By the rnid 1970's, the computational capabilities had improved io the extent that lifting-surface theories, such as vortex-lattice and panel methods, were utilized in the design process. In additiory non-linear methods were developed that could not only account for non-rigid wakes, but also optimize the wing geometry to achieve the greatest cross-country performance. These developments led to the adaptation of planforms having straight trailing edges and on to non-planar wing geometries and the, now commonplace, use of winglets. While it is not at all clear what directions wing design in the future will take, it will no doubt be influenced by technological developments such as the use of boundary-layer suction for laminar-flow control and conformable/adaptable wing geometries that \"morph\" to the optimum configuration for any given flight situation.","PeriodicalId":131722,"journal":{"name":"Technical Soaring","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117107840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

A New Airfoil Optimized For Light Aircraft Performance 一个新的机翼优化轻型飞机的性能

Technical Soaring Pub Date : 2001-09-11 DOI: 10.4271/2001-01-2991

Paul W. Dees

引用次数: 1

A new instrument for fuel consumption measurement in light aircraft and motorgliders 一种用于轻型飞机和摩托艇燃油消耗量测量的新仪器

Technical Soaring Pub Date : 2000-04-11 DOI: 10.4271/2000-01-2122

P. Morelli, P. Nuccio

引用次数: 0