An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models

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ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models by : K. S. Keen

Download or read book An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models written by K. S. Keen and published by . This book was released on 1997 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic study was conducted to evaluate anticipated ranges and required accuracies for onboard linear acceleration and angular rate (or acceleration) measurement equipment to be mounted within dynamically scaled wind tunnel drop models. Generic simulations of the separation motion of a tumbling fuel tank both at full scale and at 1/15th wind tunnel model scale were generated using an analytic trajectory simulation program coupled with a prescribed aerodynamic database. The simulations provide a basis for sizing the required instrumentation for proof of concept demonstrations of telemetry techniques in the wind tunnel. The simulations were also used as test cases to demonstrate extraction of aerodynamic information from drop data positions and orientations as read from film records via an inverse solution of the store equations of motion. The studies also aid identification and evaluation of inaccuracies associated with the basic dynamic scaling laws and standard film based data reduction techniques.

An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models

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ISBN 13 :
Total Pages : 120 pages
Book Rating : 4.:/5 (227 download)

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Book Synopsis An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models by :

Download or read book An Analytic Investigation of Accuracy Requirements for Onboard Instrumentation and Film Data for Dynamically Scaled Wind Tunnel Drop Models written by and published by . This book was released on 1997 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic study was conducted to evaluate anticipated ranges and required accuracies for onboard linear acceleration and angular rate (or acceleration) measurement equipment to be mounted within dynamically scaled wind tunnel drop models. Generic simulations of the separation motion of a tumbling fuel tank both at full scale and at 1/15th wind tunnel model scale were generated using an analytic trajectory simulation program coupled with a prescribed aerodynamic database. The simulations provide a basis for sizing the required instrumentation for proof of concept demonstrations of telemetry techniques in the wind tunnel. The simulations were also used as test cases to demonstrate extraction of aerodynamic information from drop data positions and orientations as read from film records via an inverse solution of the store equations of motion. The studies also aid identification and evaluation of inaccuracies associated with the basic dynamic scaling laws and standard film based data reduction techniques.

The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System

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Publisher :
ISBN 13 :
Total Pages : 153 pages
Book Rating : 4.:/5 (227 download)

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Book Synopsis The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System by : Irving C. Statler

Download or read book The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System written by Irving C. Statler and published by . This book was released on 1967 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cornell Aeronautical Laboratory (CAL) system provides a unique mounting through which a model can be forced precisely in any desired planar sinusoidal motion. The versatility and overall accuracy of the CAL/Air Force dynamic testing system was demonstrated during a series of wind-tunnel tests. These tests permitted, for the first time, a measurement of the separate components of the rotary damping moment. The moment due to rate of change of angle of attack was measured by oscillating the model in pure plunging motion. The moment due to pitch rate was measured during pitching motion. The sum of these is compared with the total rotary damping moment as measured in rotation. Comparisons of data taken at two frequencies and four Mach numbers indicate that the components are accurate to within plus or minus ten percent of the total rotary damping moment. The results are compared with theory, flight test data, and other wind-tunnel measurements on the same and similar models. Future applications of this equipment are reviewed, particularly with regard to its use as a research tool to support basic investigations for the development of theoretical or semiempirical methods for predicting dynamic stability characteristics of aircraft at transonic speeds. (Author).

Government Reports Announcements & Index

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ISBN 13 :
Total Pages : 782 pages
Book Rating : 4.3/5 (129 download)

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Book Synopsis Government Reports Announcements & Index by :

Download or read book Government Reports Announcements & Index written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Scientific and Technical Aerospace Reports

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ISBN 13 :
Total Pages : 1162 pages
Book Rating : 4.:/5 (31 download)

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Book Synopsis Scientific and Technical Aerospace Reports by :

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1986 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Modal Correction Method for Dynamically Induced Errors in Wind-Tunnel Model Attitude Measurements

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Publisher : Independently Published
ISBN 13 : 9781792687150
Total Pages : 28 pages
Book Rating : 4.6/5 (871 download)

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Book Synopsis Modal Correction Method for Dynamically Induced Errors in Wind-Tunnel Model Attitude Measurements by : National Aeronautics and Space Adm Nasa

Download or read book Modal Correction Method for Dynamically Induced Errors in Wind-Tunnel Model Attitude Measurements written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-30 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes a method for correcting the dynamically induced bias errors in wind tunnel model attitude measurements using measured modal properties of the model system. At NASA Langley Research Center, the predominant instrumentation used to measure model attitude is a servo-accelerometer device that senses the model attitude with respect to the local vertical. Under smooth wind tunnel operating conditions, this inertial device can measure the model attitude with an accuracy of 0.01 degree. During wind tunnel tests when the model is responding at high dynamic amplitudes, the inertial device also senses the centrifugal acceleration associated with model vibration. This centrifugal acceleration results in a bias error in the model attitude measurement. A study of the response of a cantilevered model system to a simulated dynamic environment shows significant bias error in the model attitude measurement can occur and is vibration mode and amplitude dependent. For each vibration mode contributing to the bias error, the error is estimated from the measured modal properties and tangential accelerations at the model attitude device. Linear superposition is used to combine the bias estimates for individual modes to determine the overall bias error as a function of time. The modal correction model predicts the bias error to a high degree of accuracy for the vibration modes characterized in the simulated dynamic environment. Buehrle, R. D. and Young, C. P., Jr. Langley Research Center NASA-TM-111560, NAS 1.15:111560 ...

Dependence of Dynamic Modeling Accuracy on Sensor Measurements, Mass Properties, and Aircraft Geometry

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Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781719395175
Total Pages : 42 pages
Book Rating : 4.3/5 (951 download)

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Book Synopsis Dependence of Dynamic Modeling Accuracy on Sensor Measurements, Mass Properties, and Aircraft Geometry by : National Aeronautics and Space Administration (NASA)

Download or read book Dependence of Dynamic Modeling Accuracy on Sensor Measurements, Mass Properties, and Aircraft Geometry written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NASA Generic Transport Model (GTM) nonlinear simulation was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of identified parameters in mathematical models describing the flight dynamics and determined from flight data. Measurements from a typical flight condition and system identification maneuver were systematically and progressively deteriorated by introducing noise, resolution errors, and bias errors. The data were then used to estimate nondimensional stability and control derivatives within a Monte Carlo simulation. Based on these results, recommendations are provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using additional flight conditions and parameter estimation methods, as well as a nonlinear flight simulation of the General Dynamics F-16 aircraft, were compared with these recommendations Grauer, Jared A. and Morelli, Eugene A. Langley Research Center DYNAMIC MODELS; MATHEMATICAL MODELS; FLIGHT SIMULATION; ERRORS; AIRCRAFT INSTRUMENTS; MEASURING INSTRUMENTS; SYSTEM IDENTIFICATION; COMPUTER AIDED DESIGN; MONTE CARLO METHOD; AIRCRAFT STABILITY

Dynamic Response Tests of Inertial and Optical Wind-Tunnel Model Attitude Measurement Devices

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Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722186227
Total Pages : 46 pages
Book Rating : 4.1/5 (862 download)

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Book Synopsis Dynamic Response Tests of Inertial and Optical Wind-Tunnel Model Attitude Measurement Devices by : National Aeronautics and Space Administration (NASA)

Download or read book Dynamic Response Tests of Inertial and Optical Wind-Tunnel Model Attitude Measurement Devices written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented for an experimental study of the response of inertial and optical wind-tunnel model attitude measurement systems in a wind-off simulated dynamic environment. This study is part of an ongoing activity at the NASA Langley Research Center to develop high accuracy, advanced model attitude measurement systems that can be used in a dynamic wind-tunnel environment. This activity was prompted by the inertial model attitude sensor response observed during high levels of model vibration which results in a model attitude measurement bias error. Significant bias errors in model attitude measurement were found for the measurement using the inertial device during wind-off dynamic testing of a model system. The amount of bias present during wind-tunnel tests will depend on the amplitudes of the model dynamic response and the modal characteristics of the model system. Correction models are presented that predict the vibration-induced bias errors to a high degree of accuracy for the vibration modes characterized in the simulated dynamic environment. The optical system results were uncorrupted by model vibration in the laboratory setup. Buehrle, R. D. and Young, C. P., Jr. and Burner, A. W. and Tripp, J. S. and Tcheng, P. and Finley, T. D. and Popernack, T. G., Jr. Langley Research Center RTOP 505-59-54-01...

Instrument Error Analysis as it Applies to Wind-tunnel Testing

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ISBN 13 :
Total Pages : 68 pages
Book Rating : 4.:/5 (317 download)

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Book Synopsis Instrument Error Analysis as it Applies to Wind-tunnel Testing by : Emanuel Rind

Download or read book Instrument Error Analysis as it Applies to Wind-tunnel Testing written by Emanuel Rind and published by . This book was released on 1979 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Popular Science

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ISBN 13 :
Total Pages : 128 pages
Book Rating : 4./5 ( download)

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Book Synopsis Popular Science by :

Download or read book Popular Science written by and published by . This book was released on 2007-08 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Popular Science gives our readers the information and tools to improve their technology and their world. The core belief that Popular Science and our readers share: The future is going to be better, and science and technology are the driving forces that will help make it better.

Aeronautical Engineering

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ISBN 13 :
Total Pages : 168 pages
Book Rating : 4.3/5 ( download)

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Book Synopsis Aeronautical Engineering by :

Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).

The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System

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Publisher :
ISBN 13 :
Total Pages : 32 pages
Book Rating : 4.:/5 (46 download)

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Book Synopsis The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System by : Irving C. Statler

Download or read book The Development and Evaluation of the CAL/Air Force Dynamic Wind-tunnel Testing System written by Irving C. Statler and published by . This book was released on 1967 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The F-104 model was designed and fabricated by the Air Force Flight Dynamics Laboratory and incorporated an unusual force and motion sensing system utilizing an internal dummy model with duplicate mass, inertia, and c.g. location. Longitudinal dynamic tests were performed with this model up through the transonic speed range. The results are evaluated with respect to the operation of the dynamic testing system and to the performance of the dummy model for measuring motion and canceling inertial loads.

NASA SP.

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ISBN 13 :
Total Pages : 668 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis NASA SP. by :

Download or read book NASA SP. written by and published by . This book was released on 1991 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Integrated Experimental and Numerical Research on the Aerodynamics of Unsteady Moving Aircraft

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ISBN 13 :
Total Pages : 51 pages
Book Rating : 4.:/5 (713 download)

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Book Synopsis Integrated Experimental and Numerical Research on the Aerodynamics of Unsteady Moving Aircraft by :

Download or read book Integrated Experimental and Numerical Research on the Aerodynamics of Unsteady Moving Aircraft written by and published by . This book was released on 2007 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the experimental determination of the dynamic wind tunnel data a new combined motion test capability was developed at the German-Dutch Wind Tunnels DNW for their 3m Low Speed Wind Tunnel NWB in Braunschweig, Germany, using a unique six degree-of-freedom test rig called?Model Positioning Mechanism? (MPM) as an improved successor to the older systems. With that cutting-edge device several transport aircraft configurations including a blended wing body configuration were tested in different modes of oscillatory motions roll, pitch and yaw as well as delta wing geometries like X-31 equipped with remote controlled rudders and flaps to be able to simulate realistic flight maneuvers, e.g. a dutch-roll. This paper describes the motivation behind these tests and the test setup and in addition gives a short introduction into time accurate maneuver testing capabilities incorporating models with remote controlled control surfaces. Furthermore, the adaptation of numerical methods for the prediction of dynamic derivatives is described and some examples with the DLR-F12 configuration will be given. The calculations are based on RANS-solution using the finite volume parallel solution algorithm with an unstructured discretization concept (DLR TAU-code).

High-speed Wind Tunnels

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ISBN 13 :
Total Pages : 236 pages
Book Rating : 4.E/5 ( download)

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Book Synopsis High-speed Wind Tunnels by : Luigi Crocco

Download or read book High-speed Wind Tunnels written by Luigi Crocco and published by . This book was released on 1946 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance assumed in recent times by experimental supersonic wind tunnels, as well as the power required, has brought about the need for a study which would permit a comparison of the types tested and the principal theoretical plans.

International Aerospace Abstracts

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ISBN 13 :
Total Pages : 974 pages
Book Rating : 4.F/5 ( download)

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Book Synopsis International Aerospace Abstracts by :

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

On Subscale Flight Testing

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Publisher : Linköping University Electronic Press
ISBN 13 : 9176852202
Total Pages : 112 pages
Book Rating : 4.1/5 (768 download)

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Book Synopsis On Subscale Flight Testing by : Alejandro Sobron

Download or read book On Subscale Flight Testing written by Alejandro Sobron and published by Linköping University Electronic Press. This book was released on 2018-11-05 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Downscaled physical models, also referred to as subscale models, have played an essential role in the investigation of the complex physics of flight until the recent disruption of numerical simulation. Despite the fact that improvements in computational methods are slowly pushing experimental techniques towards a secondary role as verification or calibration tools, real-world testing of physical prototypes still provides an unmatched confidence. Physical models are very effective at revealing issues that are sometimes not correctly identified in the virtual domain, and hence can be a valuable complement to other design tools. But traditional wind-tunnel testing cannot always meet all of the requirements of modern aeronautical research and development. It is nowadays too expensive to use these scarce facilities to explore different design iterations during the initial stages of aircraft development, or to experiment with new and immature technologies. Testing of free-flight subscale models, referred to as Subscale Flight Testing (SFT), could offer an affordable and low-risk alternative for complementing conventional techniques with both qualitative and quantitative information. The miniaturisation of mechatronic systems, the advances in rapid-prototyping techniques and power storage, as well as new manufacturing methods, currently enable the development of sophisticated test objects at scales that were impractical some decades ago. Moreover, the recent boom in the commercial drone industry has driven a quick development of specialised electronics and sensors, which offer nowadays surprising capabilities at competitive prices. These recent technological disruptions have significantly altered the cost-benefit function of SFT and it is necessary to re-evaluate its potential in the contemporary aircraft development context. This thesis aims to increase the comprehension and knowledge of the SFT method in order to define a practical framework for its use in aircraft design; focusing on low-cost, short-time solutions that don’t require more than a small organization and few resources. This objective is approached from a theoretical point of view by means of an analysis of the physical and practical limitations of the scaling laws; and from an empirical point of view by means of field experiments aimed at identifying practical needs for equipment, methods, and tools. A low-cost data acquisition system is developed and tested; a novel method for semi-automated flight testing in small airspaces is proposed; a set of tools for analysis and visualisation of flight data is presented; and it is also demonstrated that it is possible to explore and demonstrate new technology using SFT with a very limited amount of economic and human resources. All these, together with a theoretical review and contextualisation, contribute to increasing the comprehension and knowledge of the SFT method in general, and its potential applications in aircraft conceptual design in particular.