Download or read book IN FLIGHT MEASUREMENT AND CORRELATION WITH THEORY OF BLADE AIRLOADS AND RESPONSES ON THE XH 51A COMPOUND HELICOPTER ROTOR VOLUME 2 MEASUREMENT AND DATA REDUCTION OF AIRLOADS AND STRUCTURAL LOADS APPENDIXES 5 THROUGH 9 written by and published by . This book was released on 1968 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Differential pressure -- dynamic components; Differential pressure -- static components; Blade loads -- dynamic and static components; Harmonic components of airloads and pitching moments; Harmonic components of structural loads.
Download or read book IN FLIGHT MEASUREMENT AND CORRELATION WITH THEORY OF BLADE AIRLOADS AND RESPONSES ON THE XH 51A COMPOUND HELICOPTER ROTOR VOLUME I MEASUREMENT AND DATA REDUCTION OF AIRLOADS AND STRUCTURAL LOADS written by and published by . This book was released on 1968 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents the results of a two-phase research program consisting of (1) in-flight measurement of aerodynamic pressures and structural loads on a compound, rigid-rotor helicopter and (2) correlation of these data with theoretical results. Flight test data obtained in Phase I and recorded on an oscillograph were read on an oscillograph reading machine and were processed in an automatic data reduction program. This data processing consisted of integration of the pressure data to obtain the distribution of aerodynamic lift and pitching moments over the rotor blade, as functions of azimuth position. Airload and structural load data were harmonically analyzed. Output of the data reduction program was used in Phase II as input to the correlation program. The measured airloads were used to compute the theoretical bending and torsion responses of the blade. The measured torsion moments were used in the theoretical prediction of the airloads. The results of the applied theories are compared with the flight measurements.
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the Xh 51a Compound Helicopter Rotor written by E.A. Bartsch and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the XH 51A Compound Helicopter Rotor Measurement and data reduction of airloads and structural loads written by and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents the results of a two-phase research program consisting of (1) in-flight measurement of aerodynamic pressures and structural loads on a compound, rigid-rotor helicopter and (2) correlation of these data with theoretical results. Flight test data obtained in Phase I and recorded on an oscillograph were read on an oscillograph reading machine and were processed in an automatic data reduction program. This data processing consisted of integration of the pressure data to obtain the distribution of aerodynamic lift and pitching moments over the rotor blade, as functions of azimuth position. Airload and structural load data were harmonically analyzed. Output of the data reduction program was used in Phase II as input to the correlation program. The measured airloads were used to compute the theoretical bending and torsion responses of the blade. The measured torsion moments were used in the theoretical prediction of the airloads. The results of the applied theories are compared with the flight measurements.
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the XH 51A Compound Helicopter Rotor written by and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents the results of a two-phase research program consisting of (1) in-flight measurement of aerodynamic pressures and structural loads on a compound, rigid-rotor helicopter and (2) correlation of these data with theoretical results. Flight test data obtained in Phase I and recorded on an oscillograph were read on an oscillograph reading machine and were processed in an automatic data reduction program. This data processing consisted of integration of the pressure data to obtain the distribution of aerodynamic lift and pitching moments over the rotor blade, as functions of azimuth position. Airload and structural load data were harmonically analyzed. Output of the data reduction program was used in Phase II as input to the correlation program. The measured airloads were used to compute the theoretical bending and torsion responses of the blade. The measured torsion moments were used in the theoretical prediction of the airloads. The results of the applied theories are compared with the flight measurements.
Download or read book NASA Technical Note written by and published by . This book was released on 1974 with total page 808 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 1968 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the Xh 51a Compound Helicopter Rotor written by J.E. Sweers and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book IN FLIGHT MEASUREMENT AND CORRELATION WITH THEORY OF BLADE AIRLOADS AND RESPONSES ON THE XH 51A COMPOUND HELICOPTER ROTOR VOLUME 3 THEORETICAL PREDICTION OF AIRLOADS AND STRUCTURAL LOADS AND CORRELATION WITH FLIGHT TEST MEASUREMENTS written by and published by . This book was released on 1968 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: In most of the conditions analyzed, the computed bending moments were found to be in good agreement with the measured moments. The agreement between computed and measured torsion moments, however, was poor, indicating that improvements are required in the mathematical model as far as the torsional properties are concerned. (These may include the introduction of the control system degrees of freedom in the model.) Comparison of measurements with airloads obtained with the Cornell program shows good agreement of the variations of the airloads over the azimuth. At the lower forward speeds the rotor wake can be represented by a set of ring vortexes. An urgent need exists for a method for predicting wake deformation and for programming this method. Torsional responses are important in the computation of airloads. A rotor trim procedure included in a rotor loads program has been shown to be useful in the prediction of rotor loads. Based on the results obtained for chordwise bending moments, the relationship between normal force coefficient and chord force coefficient used in Lockheed Program I should be reexamined, particularly in high angle-of-attack areas. Such investigation may result in improved estimates of drag coefficients.
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the XH 51A Compound Helicopter Rotor written by E. A. Bartsch and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In flight Measurement and Correlation with Theory of Blade Airloads and Responses on the XH 51A Compound Helicopter Rotor written by J. E. Sweers and published by . This book was released on 1968 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlation of Airloads on a Two bladed Helicopter Rotor written by Francisco J. Fernandez and published by . This book was released on 1993 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlation of Airloads on a Two Bladed Helicopter Rotor written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Airloads measured on a two-bladed helicopter rotor in flight during the Ames' Tip Aerodynamic and Acoustic Test are compared with calculations from a comprehensive helicopter analysis (CAMRAD/JA), and the pressures compared with calculations from a full-potential rotor code (FPR). The flight-test results cover an advance ratio range of 0.19 to 0.38. The lowest-speed case is characterized by the presence of significant blade-vortex interactions. Good correlation of peak-to-peak vortex-induced loads and the corresponding pressures is obtained. Results of the correlation for this two-bladed rotor are substantially similar to those for three- and four-bladed rotors, including the tip-vortex core size for best correlation, calculation of the peak-to-peak loads on the retreating side, and calculation of vortex iduced loads on inboard radial stations. The higher-speed cases are characterized by the presence of transonic flow on the outboard sections of the blade. Comparison of calculated and measured airloads on the advancing side is not considered appropriate because the presence of shocks makes chordwise integration of the measured data difficult. However, good correlation of the corresponding pressures is obtained. Fernandez, Francisco J. and Johnson, Wayne Ames Research Center RTOP 505-59-36...
Download or read book In flight Measurement of Rotor Blade Airloads Bending Moments and Motions Together with Rotor Shaft Loads and Fuselage Vibration on a Tandem Rotor Helicopter Volume Ii Calibrations and Instrumented Component Testing written by William J. Grant and published by . This book was released on 1967 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Calibration and instrumented component testing were performed to provide reliable instrumentation for the measurement of dynamic airloads on a large tandem rotor helicopter. All equipment underwent single-load calibration and much of it was calibrated for combined loads. Blade tension instrumentation was calibrated by whirl testing. The combined-loads calibrations represent an extension of the state of the art, especially for elastic structures such as rotor blades. All calibrations were evaluated qualitatively and a summary of the quality of all calibrations is presented. The general error in all calibrations is less than 3 percent. Component testing consisted of whirl tests and dynamic response tests of the rotor blades, and functional testing of the airloads pressure transducers. These tests determined the structural itegrity of the blade instrumentation and provided references for isolating the effects of such factors as blade bending, acceleration, and temperature. (Author).
Download or read book In flight Measurement of Rotor Blade Airloads Bending Moments and Motions Together with Rotor Shaft Loads and Fuselage Vibration on a Tandem Rotor Helicopter Volume Iv Summary and Evaluation of Results written by Richard R. Pruyn and published by . This book was released on 1967 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report describes and evaluates the results of an extensive program to measure the dynamic effects of flight on a tandem rotor helicopter. The flight test results are reviewed and then compared with theoretical predictions and with other flight test data. The airloads measurements from this program are similar to those of other flight test programs, with one major exception: single lifting-rotor helicopter data differ from the forward rotor data of a tandem. The aft rotor apparently produces an upwash which gives an increase in the airloads on the inboard region of the forward rotor. This effect results in an airload distribution that is similar to that which would be obtained with an increased blade twist of the forward rotor. For most longitudinal cyclic trim settings, the oscillations of the airloads of both tandem rotors tend to be similar to those of a single rotor, with intrarotor tip vortex intersections causing the predominant disturbances. Longitudinal cyclic trim settings can be obtained experimentally with the tandem helicopter which cause large airload pressure oscillations due to the intersection of forward rotor blade vortexes by the aft rotor blades. These pressure oscillations occur rapidly and do not appear to increase blade stresses, rotor shaft loads, or airframe vibration. (Author).
Download or read book IN FLIGHT MEASUREMENT OF ROTOR BLADE AIRLOADS BENDING MOMENTS AND MOTIONS TOGETHER WITH ROTOR SHAFT LOADS AND FUSELAGE VIBRATION ON A TANDEM ROTOR HELICOPTER VOLUME 5 INVESTIGATION OF BLADE STALL CONDITIONS written by and published by . This book was released on 1968 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report describes the results of an investigation into helicopter rotor blade stall conditions. The goals of this research were to increase the comprehension of blade stall and to aid in the future design of rotor blades with greater aerodynamic efficiency. The problem of rotor blade stall is discussed, covering areas such as rotor performance limitations, static airfoil section performance, dynamic and aerodynamic effects of the rotor environment, and radial flow effects. The results of the tests are presented and described in detail; they include tests at the high dynamic loads boundary, evidence of stall in rotor loads and blade motion data, coefficients of rotor airloads, and indications of negative aerodynamic damping. The test results are weighed against theoretical methods of prediction for purposes of comparison. The use of airloads measurements in the synthesis of airfoil data is investigated and a method for doing so is provided. The conclusions drawn from these tests are presented and recommendations for future research in this field are given.
Download or read book In flight Measurement of Rotor Blade Airloads Bending Moments and Motions Together with Rotor Shaft Loads and Fuselage Vibration on a Tandem Rotor Helicopter Volume I Instrumentation and In flight Recording System written by Roy Golub and published by . This book was released on 1967 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensively instrumented tandem rotor helicopter was developed to measure the rotor blade airloads and the resulting rotor blade motions and bending moments, rotor shaft loads and moments, and fuselage vibration. The report details the design, assembly, and testing of the instrumentation system and documents the capability of the system for fulfilling the requirements of the program. The selection and testing of the system components are described in detail, along with the integration of these components into the overall instrumentation and recording system. The exhaustive tests of the system, both on the ground and in flight, are described in step-by-step sequence. The capacities and capabilities of the system are delineated and illustrated. Four technical appendixes, giving precise engineering data and statistical records, are included in the report. (Author).
