Download or read book Experimental Investigation of the Effect of Propeller Blade Pitch on Propeller produced Unsteady Bearing Forces and Moments written by D. T. Valentine and published by . This book was released on 1976 with total page 52 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 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of the Unsteady Forces Acting on a Reactangular Flat Plate Due to the Action of a Propeller written by August F. Lehman and published by . This book was released on 1968 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was undertaken in a water tunnel to determine the effect of propeller blade thickness, operating KT value, propeller tip-plate clearance and plate width on the forces, moments and pressure induced on a flat plate. The plate was oriented so as to be parallel with the rotational axis of the propeller. Propellers having three blades were tested, with one propeller design having blade thicknesses double that of the other but with both propellers having equal thrust - RPM performance. Plate widths were equal to 1 and 3 propeller radii, with the length of the plate constant at 6 propeller radii. The pressure was measured by a small flush mounted transducer located in the center of the plate surface and directly over the propeller. A comparison of certain theoretical predictions with the experimental force and pressure data resulted in generally good agreement. (Author).

Download or read book MRIS Abstracts written by Maritime Research Information Service and published by . This book was released on 1981-06 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propellers 81 written by and published by . This book was released on 1981 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Multiple Blade Rate Unsteady Propeller Forces written by Stuart D. Jessup and published by . This book was released on 1990 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of unsteady propeller forces was conducted using model propellers operating in idealized axial wakes. Three-bladed propellers were operated behind 3-, 6-, 9- and 12-cycle wake screens generating blade rate and multiple axial wake inflow harmonics. The axial wake distributions were measured using a Pitot tube. Unsteady propeller bearing thrust and torque were measured with an unsteady force dynamometer. Measurements were compared to calculations using unsteady propeller lifting surface theory. Also, Laser Doppler Velocimetry (LDV) was used to measure the unsteady flow field about the propeller. LDV measurements were used to evaluate the effect of the propeller on the incoming wake. Keywords: Marine propellers; Unsteady loads; Bearing forces; Model tests; Propeller blades. (edc).

Download or read book NBS Special Publication written by and published by . This book was released on 1976 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Abstracts of the British Ship Research Association written by British Ship Research Association and published by . This book was released on 1977 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consists largely of abstracts of articles and papers of interest to shipbuilders, ship owners and marine engineers.

Download or read book Hydraulic Research in the United States and Canada 1974 written by Pauline H. Gurewitz and published by . This book was released on 1976 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Unsteady and Mean Loads on a CP Propeller Blade on a Model of the FF 1088 for Simulated Modes of Operation written by Robert J. Boswell and published by . This book was released on 1976 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments are described in which the mean and unsteady loads were measured on a single blade of a model of the controllable-pitch propeller on the FF-1088. The experiments were conducted behind a model of the FF-1088 hull under steady ahead operation, hull pitching motions, simulated crash ahead maneuvers, and simulated crash astern maneuvers. The experimental techniques are outlined and the dynamometer and data analysis system described. The results show that the circumferential variation of all measured components of blade loading is primarily a once-per-revolution variation, with maximum and minimum values occurring near the angular positions in which the spindle axis is horizontal. For sinusoidal pitching of the model hull with amplitude of 2 deg and frequency of 0.8 Hz, the peak-to-peak circumferential variation of measured forces and moments increased by a minimum of 50 percent over the values without hull pitching. For simulated operation during a crash ahead or crash astern maneuver, the circumferential variation of measured forces and moments varied approximately as the product of ship speed and propeller rotational speed, and was a function of propeller pitch. At no time during the simulated crash ahead or crash astern maneuvers were the circumferential variations of loads as large as during steady ahead operation. For steady ahead operation, circumferential variation of loading determined from the model experiments agreed fairly well with full-scale data, but was substantially larger than the theoretically calculated values. (Author).

Download or read book SSC written by and published by . This book was released on 1946 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Wind tunnel Investigation of Three Propellers Through an Angle of attack Range from 0 Degree to 85 Degrees written by Paul F. Yaggy and published by . This book was released on 1960 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydraulic Research in the United States and Canada written by and published by . This book was released on 1972 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Propeller Loading Measurement Correlation With Theory and Parametric Study written by Robert J. Boswell and published by . This book was released on 1968 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives of the present study are to measure the unsteady forces and moments on a series of marine propellers due to circumferentially nonuniform inflow; to correlate the measured unsteady thrust and torque with calculated values, based on various proposed theories; and to investigate variation of unsteady thrust and torque over a range of pertinent parameters, using the method determined from those described to be the best available for calculating unsteady loading. Experimental blade-frequency thrust and torque were compared with values calculated by the following techniques: quasi-steady, two-dimensional unsteady, combination quasi-steady two-dimensional unsteady, and three-dimensional unsteady. The three-dimensional unsteady theory yields the best correlation with experiment; however, the numerical techniques employed breakdown for narrow-bladed propellers and for propellers with blade overlap.

Download or read book Measurement of Forces and Spindle Moments on Individual Blades of a Large hubbed Propeller written by Stephen B. Denny and published by . This book was released on 1969 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Axial forces, torque forces and spindle moments were measured on the individual blades of a six-bladed large-hubbed propeller. Two different propeller-blade configurations were tested, and the hydrodynamic characteristics of each were determined over wide ranges of blade pitch and advance conditions. The experimental results indicated the peak forces and moments on propeller blades during emergency operating conditions as well as blade loads and propeller efficiencies during normal cruise operation. Also, by assuming a given blade rake relative to the propeller rotation plane and by vector resolution of the blade forces determined at zero advance for various pitches, it was possible to calculate the extent of propeller sideforce capability during cyclic pitch operation. The test results show that a mission requirement for large-hubbed cyclic-pitch propellers which calls for sizeable side-force capability for maneuvering will dictate the use of large blades that are not efficient in vehicle cruise modes. Recommendations are made for further investigations of blade-configuration and blade-rake effects on both propeller side-force capability and ahead propulsion. (Author).

Download or read book Experimental Determination of Unsteady Forces on Contrarotating Propellers for Application to Torpedoes written by and published by . This book was released on 1981 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents results of measurements of unsteady forces and moments on 4x4 and 4x5 bladed sets of contrarotating propellers in uniform flow and in a 4-cycle wake for application to torpedo propeller design. The uniform flow measurements were made to check earlier results that had been in disagreement with the results from calculations based on propeller theory. The uniform flow results confirmed the earlier results in showing larger forces on the forward propeller which is contrary to the prediction of existing theory. The results of the experiments in the 4-cycle wake showed unsteady forces on the forward propeller due to the effect of the wake along with the interaction forces between the two propellers. No theoretical calculations are available for comparison with the wake results. The present procedure for conducting unsteady force and moment measurements on contrarotating propellers continues to be tedious and easily subject to error. Consequently, it is recommended that no further experiments be conducted using this procedure. It is recommended that for future experiments on contrarotating propellers the shafts be locked together mechanically and that a second dynamometer be used so that unsteady measurements can be made on both propellers simultaneously. (Author).