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Book Performance Analysis of Two Early NACA High Speed Propellers with Application to Civil Tiltrotor Configurations

Download or read book Performance Analysis of Two Early NACA High Speed Propellers with Application to Civil Tiltrotor Configurations written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-19 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The helicopter industry is vigorously pursuing development of civil tiltrotors. One key to efficient high speed performance of this rotorcraft is prop-rotor performance. Of equal, if not greater, importance is assurance that the flight envelope is free of aeroelastic instabilities well beyond currently envisioned cuise speeds. This later condition requires study at helical tip Match numbers well in excess of 1.0. Two 1940's 'supersonic' propeller experiments conducted by NACA have provided an immensely valuable data bank with which to study prop-rotor behavior at transonic and supersonic helical tip Mach numbers. Very accurate 'blades alone' data were obtained by using nearly an infinite hub. Tabulated data were recreated from the many thrust and power figures and are included in two Appendices to this report. This data set is exceptionally well suited to re-evaluating classical blade element theories as well as evolving computational fluid dynamic (CFD) analyses. A limited comparison of one propeller's experimental results to a modem rotorcraft CFD code is made. This code, referred to as TURNS, gives very encouraging results. Detailed analysis of the performance data from both propellers is provided in Appendix A. This appendix quantifies the minimum power required to produce usable prop-rotor thrust. The dependence of minimum profile power on Reynolds number is quantified. First order compressibility power losses are quantified as well and a first approximation to design air-foil thickness ratio to avoid compressibility losses is provided. Appendix A's results are applied to study high speed civil tiltrotor cruise performance. Predicted tiltrotor performance is compared to two turboprop commercial transports. The comparison shows that there is no fundamental aerodynamic reason why the rotorcraft industry could not develop civil tiltrotor aircraft which have competitive cruise performance with today's regional, turboprop airlines. Recommendations for future study t...

Book Tests of Two blade Propellers in the Langley 8 foot High speed Tunnel to Determine the Effect on Propeller Performance of a Modification of Inboard Pitch Distribution

Download or read book Tests of Two blade Propellers in the Langley 8 foot High speed Tunnel to Determine the Effect on Propeller Performance of a Modification of Inboard Pitch Distribution written by James Benjamin Delano and published by . This book was released on 1951 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents propeller characteristics for two propellers that differ only in inboard pitch distribution. The forward Mach number range extended to 0.062 and the blade-angle range was from 20 to 55 degrees. Section thrust-coefficient data are also presented to afford a more detailed analysis of the effects of modifying the pitch distribution of the inboard sections of a propeller.

Book The History of the XV 15 Tilt Rotor Research Aircraft

Download or read book The History of the XV 15 Tilt Rotor Research Aircraft written by Martin D. Maisel and published by . This book was released on 2000 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Analysis for High Speed Propeller Nacelle Aerodynamic Performance Prediction Volume 1

Download or read book An Analysis for High Speed Propeller Nacelle Aerodynamic Performance Prediction Volume 1 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computer program, the Propeller Nacelle Aerodynamic Performance Prediction Analysis (PANPER), was developed for the prediction and analysis of the performance and airflow of propeller-nacelle configurations operating over a forward speed range inclusive of high speed flight typical of recent propfan designs. A propeller lifting line, wake program was combined with a compressible, viscous center body interaction program, originally developed for diffusers, to compute the propeller-nacelle flow field, blade loading distribution, propeller performance, and the nacelle forebody pressure and viscous drag distributions. The computer analysis is applicable to single and coaxial counterrotating propellers. The blade geometries can include spanwise variations in sweep, droop, taper, thickness, and airfoil section type. In the coaxial mode of operation the analysis can treat both equal and unequal blade number and rotational speeds on the propeller disks. The nacelle portion of the analysis can treat both free air and tunnel wall configurations including wall bleed. The analysis was applied to many different sets of flight conditions using selected aerodynamic modeling options. The influence of different propeller nacelle-tunnel wall configurations was studied. Comparisons with available test data for both single and coaxial propeller configurations are presented along with a discussion of the results. Egolf, T. Alan and Anderson, Olof L. and Edwards, David E. and Landgrebe, Anton J. Unspecified Center NASA-CR-4199-VOL-1, E-4382, NAS 1.26:4199-VOL-1 NAS3-20961; NAS3-22142; NAS3-22257; RTOP 535-03-01...

Book An Analysis for High Speed Propeller Nacelle Aerodynamic Performance Prediction Volume 2

Download or read book An Analysis for High Speed Propeller Nacelle Aerodynamic Performance Prediction Volume 2 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: A user's manual for the computer program developed for the prediction of propeller-nacelle aerodynamic performance reported in, An Analysis for High Speed Propeller-Nacelle Aerodynamic Performance Prediction: Volume 1 -- Theory and Application, is presented. The manual describes the computer program mode of operation requirements, input structure, input data requirements and the program output. In addition, it provides the user with documentation of the internal program structure and the software used in the computer program as it relates to the theory presented in Volume 1. Sample input data setups are provided along with selected printout of the program output for one of the sample setups. Egolf, T. Alan and Anderson, Olof L. and Edwards, David E. and Landgrebe, Anton J. Unspecified Center NASA-CR-4199-VOL-2, E-4399, NAS 1.26:4199-VOL-2 NAS3-20961; NAS3-22142; NAS3-22257; RTOP 535-03-01...

Book Tests of Two blade Propellers in the Langley 8 foot High speed Tunnel to Determine the Effect on Propeller Performance of a Modification of Inboard Pitch Distribution

Download or read book Tests of Two blade Propellers in the Langley 8 foot High speed Tunnel to Determine the Effect on Propeller Performance of a Modification of Inboard Pitch Distribution written by James B. Delano and published by . This book was released on 1945 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Summary and Recent Results from the NASA Advanced High Speed Propeller Research Program

Download or read book Summary and Recent Results from the NASA Advanced High Speed Propeller Research Program written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced high-speed propellers offer large performance improvements for aircraft that cruise in the Mach 0.7 to 0.8 speed regime. The current status of the NASA research program on high-speed propeller aerodynamics, acoustics, and aeroelastics is described. Recent wind tunnel results for five 8- to 10-blade advanced models are compared with analytical predictions. Test results show that blade sweep was important in achieving net efficiencies near 80 percent at Mach 0.8 and reducing near-field cruise noise by dB. Lifting line and lifting surface aerodynamic analysis codes are under development and some initial lifting line results are compared with propeller force and probe data. Some initial laser velocimeter measurements of the flow field velocities of an 8-bladed 45 deg swept propeller are shown. Experimental aeroelastic results indicate that cascade effects and blade sweep strongly affect propeller aeroelastic characteristics. Comparisons of propeller near-field noise data with linear acoustic theory indicate that the theory adequate predicts near-field noise for subsonic tip speeds but overpredicts the noise for supersonic tip speeds. Potential large gains in propeller efficiency of 7 to 11 percent at Mach 0.8 may be possible with advanced counter-rotation propellers. Mitchell, G. A. and Mikkelson, D. C. Glenn Research Center NASA-TM-82891, E-1269, NAS 1.15:82891 RTOP 535-03-12...

Book Introduction to autogyros helicopters and other V STOL aircraft

Download or read book Introduction to autogyros helicopters and other V STOL aircraft written by Franklin D. Harris and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Aeroacoustics of Flight Vehicles

Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Aeordynamic Characteristics of a Two Blade NACA 10 3 062 045 Propeller and of a Two Blade NACA 10 3 08 045 Propeller

Download or read book Aeordynamic Characteristics of a Two Blade NACA 10 3 062 045 Propeller and of a Two Blade NACA 10 3 08 045 Propeller written by and published by . This book was released on 1953 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the investigation to determine the influence of blade-section thickness ratio on propeller performance, tests were made in the Langley 16-foot high-speed tunnel to determine the aerodynamic characteristics of the two-blade NACA 10-(3)(062)-045 propeller and of the two-blade NACA 10-(3)(08)-045 propeller. Data were obtained over a blade-angle range from 20 deg to 55 deg as measured at the 0.75-radius station, the various constant values of rotational speed used giving a range of advance ratio from 0.5 to 3.8. Maximum efficiencies of the order of 91.5 to 92 percent were obtained for the propellers. The propeller with the thinner airfoil sections over the outboard portion of the blades, the NACA 10-(3)(062)-045 propeller, had lower losses at high tip speeds, the difference amounting to about 5 percent at a helical tip Mach number of 1.10.