Download or read book Considerations of Methods of Improving Helicopter Efficiency written by Richard C. Dingeldein and published by . This book was released on 1961 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Considerations of Methods of Improving Helicopter Efficiency written by Richard C. Dingeldein and published by . This book was released on 1961 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent NASA helicopter research indicates that significant improvements in hovering efficiency, up to 7 percent, are available from the use of a special airfoil section formed by combining an NACA 632A015 thickness distribution with an NACA 230 mean line. This airfoil should be considered for flying-crane-type helicopters. Application of standard leading-edge roughness causes a large drop in efficiency; however, the cambered rotor is shown to retain its superiority over a rotor having a symmetrical airfoil when both rotors have leading-edge roughness. A simple analysis of available rotor static-thrust data indicates a greatly reduced effect of compressibility effects on the rotor profile-drag power than predicted from calculations. Preliminary results of an experimental study of helicopter parasite drag indicate the practicability of achieving an equivalent flat-plate parasite-drag area of less than 4 square feet for a rotor-head-pylon-fuselage configuration (landing gear retracted) in the 2,000-pound minimum-flying-weight class. The large drag penalty of a conventional skid-type landing (3.6 square feet) can be reduced by two-thirds by careful design. Clean, fair, and smooth fuselages that tend to have narrow, deep cross sections are shown to have advantages from the standpoint of drag and download. A ferry range of the order of 1,500 miles is indicated to be practicable for the small helicopter considered.

Download or read book NASA Technical Note written by and published by . This book was released on 1962 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Requirements for Development of Improved Helicopter Rotor Efficiency written by and published by . This book was released on 1976 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Theory written by Wayne Johnson and published by Courier Corporation. This book was released on 2012-03-07 with total page 1122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monumental engineering text covers vertical flight, forward flight, performance, mathematics of rotating systems, rotary wing dynamics and aerodynamics, aeroelasticity, stability and control, stall, noise, and more. 189 illustrations. 1980 edition.

Download or read book Technical Abstract Bulletin written by Defense Documentation Center (U.S.) and published by . This book was released on 1961-04 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 1976 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SAFETY Considerations written by and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Linear and Nonlinear Control of Small Scale Unmanned Helicopters written by Ioannis A. Raptis and published by Springer. This book was released on 2012-12-01 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been significant interest for designing flight controllers for small-scale unmanned helicopters. Such helicopters preserve all the physical attributes of their full-scale counterparts, being at the same time more agile and dexterous. This book presents a comprehensive and well justified analysis for designing flight controllers for small-scale unmanned helicopters guarantying flight stability and tracking accuracy. The design of the flight controller is a critical and integral part for developing an autonomous helicopter platform. Helicopters are underactuated, highly nonlinear systems with significant dynamic coupling that needs to be considered and accounted for during controller design and implementation. Most reliable mathematical tools for analysis of control systems relate to modern control theory. Modern control techniques are model-based since the controller architecture depends on the dynamic representation of the system to be controlled. Therefore, the flight controller design problem is tightly connected with the helicopter modeling. This book provides a step-by-step methodology for designing, evaluating and implementing efficient flight controllers for small-scale helicopters. Design issues that are analytically covered include: • An illustrative presentation of both linear and nonlinear models of ordinary differential equations representing the helicopter dynamics. A detailed presentation of the helicopter equations of motion is given for the derivation of both model types. In addition, an insightful presentation of the main rotor's mechanism, aerodynamics and dynamics is also provided. Both model types are of low complexity, physically meaningful and capable of encapsulating the dynamic behavior of a large class of small-scale helicopters. • An illustrative and rigorous derivation of mathematical control algorithms based on both the linear and nonlinear representation of the helicopter dynamics. Flight controller designs guarantee that the tracking objectives of the helicopter's inertial position (or velocity) and heading are achieved. Each controller is carefully constructed by considering the small-scale helicopter's physical flight capabilities. Concepts of advanced stability analysis are used to improve the efficiency and reduce the complexity of the flight control system. Controller designs are derived in both continuous time and discrete time covering discretization issues, which emerge from the implementation of the control algorithm using microprocessors. • Presentation of the most powerful, practical and efficient methods for extracting the helicopter model parameters based on input/output responses, collected by the measurement instruments. This topic is of particular importance for real-life implementation of the control algorithms. This book is suitable for students and researches interested in the development and the mathematical derivation of flight controllers for small-scale helicopters. Background knowledge in modern control is required.

Download or read book Index of N A S A Technical Publications written by United States. National Aeronautics and Space Administration and published by . This book was released on 1960 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Selected Listing of NASA Scientific and Technical Reports for written by and published by . This book was released on 1960 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Securing the Future of U S Air Transportation written by National Research Council and published by National Academies Press. This book was released on 2003-12-18 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: As recently as the summer of 2001, many travelers were dreading air transportation because of extensive delays associated with undercapacity of the system. That all changed on 9/11, and demand for air transportation has not yet returned to peak levels. Most U.S. airlines continue to struggle for survival, and some have filed for bankruptcy. The situation makes it difficult to argue that strong action is urgently needed to avert a crisis of undercapacity in the air transportation system. This report assesses the visions and goals for U.S. civil aviation and technology goals for the year 2050.

Download or read book Proceedings of the Annual National Forum written by American Helicopter Society and published by . This book was released on with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1961 with total page 1878 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Performance Stability and Control written by Raymond W. Prouty and published by Brooks/Cole. This book was released on 1986 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhancing Human Performance written by National Research Council and published by National Academies Press. This book was released on 1988-01-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: In its evaluation, Enhancing Human Performance reviews the relevant materials, describes each technique, makes recommendations in some cases for further scientific research and investigation, and notes applications in military and industrial settings. The techniques address a wide range of goals, from enhancing classroom learning to improving creativity and motor skills.