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Effect of distance on airplane noise

Description: Report presenting a review of literature to determine the frequency of sound of a given source strength that is loudest at various distances from the source. Frequencies in the range from 500 to 1000 cycles per second were found to be the easiest to hear, even at a distance of several miles. Sound data obtained from a light trainer airplane showed good agreement with predictions.
Date: June 1947
Creator: Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Free-space oscillating pressures near the tips of rotating propellers

Description: Report presenting the theory for calculating the free-space oscillating pressures associated with a rotating propeller at any point in space. Good agreement was found between analytical and experimental results using this method. Results regarding vibration and sound levels in the fuselage in relation to pressure level are reported.
Date: April 1949
Creator: Hubbard, Harvey H. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Free-space oscillating pressures near the tips of rotating propellers

Description: The theory is given for calculating the free-space oscillating pressures associated with a rotating propeller, at any point in space. Because of its complexity this analysis is convenient only for use in the critical region near the propeller tips where the assumptions used by Gutin to simplify his final equations are not valid. Good agreement was found between analytical and experimental results in the tip Mach number range 0.45 to two, three, four, five, six, on eight-blade propellers and for a range of tip clearances from 0.04 to 0.30 times the propeller diameter. If the power coefficient, tip Mach number, and the tip clearance are known for a given propeller, the designer may determine from these charts the average maximum free-space oscillating pressure in the critical region near the plane of rotation. A section of the report is devoted to the fuselage response to these oscillating pressures and indicates some of the factors to be considered in solving the problems of fuselage vibration and noise.
Date: 1950
Creator: Hubbard, Harvey H. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

The problem of noise reduction with reference to light airplanes

Description: From Summary: "Experiments by Deming at the Langley Memorial Aeronautical Laboratory confirm completely the formula of Gutin, which permits the convenient calculation of the sound level of any airplane propeller at low forward speeds. A simplification of the Gutin formula has been achieved by the use of a set of functions giving the sound level in the direction of maximum intensity. The sound level can be read from graphs of the functions for various numbers of blades and tip speeds. Two numerical examples and one experimental example are included; also, a radical fan-type propeller is tentatively treated."
Date: August 1946
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Propeller-loudness charts for light airplanes

Description: Report presenting calculations of the rotational-noise and vortex-noise loudness levels at distances of 300 and 1000 feet for a variety of propellers with different blade numbers, diameters, and rotational speeds. Calculated results are presented in a chart for designers of propellers.
Date: July 1947
Creator: Hubbard, Harvey H. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Recent experimental flutter studies

Description: Report presenting some highlights of recent experimental studies of flutter at high speeds. Flutter problems have become more varied with the advent of transonic flight and importance of aeroelasticity, and the flutter field has merged with other aspect of aeroelasticity such as divergence and buffeting. The two main subjects of flutter, classical flutter and stall flutter, are explored in these studies.
Date: June 12, 1951
Creator: Regier, Arthur A. & Martin, Dennis J.
Partner: UNT Libraries Government Documents Department

Vibration surveys of the P-47-B rudder and fin-rudder assembly

Description: Report presenting a study of the flutter characteristics of the P-47 tail assembly, which included replacing the original fabric-covered rudder with a metal-covered rudder and reinforcing the fin. Figures are provided for different configurations and the cycles per second under the same conditions are provided.
Date: April 1943
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Vibration surveys of the P-40 rudder and fin-rudder assembly

Description: From Report: "The following surveys on the vibration response of the P-40 rudder and fin-rudder assembly were conducted during the fall of 1942 for the purpose of obtaining information on the flutter characteristics of high-speed airplanes of known performance. The tests on the rudder alone were made with the rudder suspended in a floating condition; the tests on the fin-rudder unit were made with the fin rigidly fastened to a concrete base." A variety of figures and diagrams for the assembly are provided.
Date: April 1943
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Vibration-response tests of a 1/5-scale model of the Grumman F6F airplane in the Langley 16-foot high-speed tunnel

Description: Report discussing vibration experiments on a model of the Grumman F6F at up to 500 miles per hour. There was no indication of actual flutter by shift or frequencies or by decreasing dampening. The symmetrical and unsymmetrical bending frequencies and responses are provided.
Date: November 18, 1944
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Effect of the lift coefficient on propeller flutter

Description: Report presenting flutter of propellers at high angles of attack and flutter data obtained in connection with tests of models of large wind-tunnel propellers. The stall flutter speed was found to be much lower than the calculated classical flutter speed. That flutter speed is only obtainable if the propeller operates at the ideal angle of zero twist.
Date: July 1945
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Factors affecting the design of quiet propellers

Description: From Summary: "The problems associated with propeller noise and with the design of propellers that are less noisy than those conventionally used are presented. Three aspects of these problems are discussed: acoustical, aerodynamic, and structural. Some of the factors which must be considered in the design of a quiet propeller are outlined."
Date: September 19, 1947
Creator: Regier, Arthur A. & Hubbard, Harvey H.
Partner: UNT Libraries Government Documents Department

Initial experiments on flutter of unswept cantilever wings at Mach number 1.3

Description: Report presenting tunnel testing of the flutter of 12 widely different unswept cantilever wings with a variety of mass-density parameters, center-of-gravity positions, and elastic-axis positions. Results regarding the flutter parameters, flutter-speed coefficients, effect of airfoil-section shape on flutter, and aspect-ratio effects are provided.
Date: November 1954
Creator: Tuovila, W. J.; Baker, John E. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Initial experiments on flutter of unswept cantilever wings at Mach number 1.3

Description: Report presenting the results of a preliminary experimental flutter investigation of widely different unswept cantilever wings at Mach number 1.3. Wings with a variety of mass-density parameters, center-of-gravity positions, and elastic-axis positions were tested.
Date: January 6, 1949
Creator: Tuovila, W. J.; Baker, John E. & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department

Effect of critical Mach number and flutter on maximum power loading of ducted fans

Description: Report presenting flutter tests of two wind-tunnel-fan models, one with conventional Clark Y airfoil sections and one with high-camber blade sections. The results indicated that higher flutter speeds were present for high lift coefficients for high-camber blades. Results regarding lift coefficients, blade-tip twisting, power loading, critical Mach numbers, flutter point, vibrational frequencies, and stall-flutter tip Mach number are provided.
Date: June 1947
Creator: Regier, Arthur A.; Barmby, John G. & Hubbard, Harvey H.
Partner: UNT Libraries Government Documents Department