National Advisory Committee for Aeronautics (NACA) - 35 Matching Results

Search Results

Flight and test-stand investigation of high-performance fuels in Pratt & Whitney R-1830-94 engines IV : comparison of cooling characteristics of flight and test-stand engines

Description: The cooling characteristics of three R-1830-94 engines, two of which were mounted in a test stand and the other in a B-24D airplane, were investigated and the results were compared. The flight tests were made at a pressure altitude of 7000 feet; the test-stand runs were made at ground-level atmospheric conditions. Three cooling runs were made for each engine: variable cooling-air pressure drop, variable carburetor-air flow, and variable fuel-air ratio. Actual cylinder temperatures of the three engines at nearly the same operating conditions of charge-air flow, fuel-air ratio, and cooling-air pressure drop paralleled predicted temperatures for the same conditions. This result was found to be true for a limited period of engine running time, this period coinciding with the time during which the cooling-correlation data were taken.
Date: October 8, 1946
Creator: Werner, Milton & Dandois, Marcel
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8, and 19XB-1 Jet-Propulsion Engines. II - Analysis of Turbine Performance of the 19B-8 Engine

Description: Performance characteristics of the turbine in the 19B-8 jet propulsion engine were determined from an investigation of the complete engine in the Cleveland altitude wind tunnel. The investigation covered a range of simulated altitudes from 5000 to 30,000 feet and flight Mach numbers from 0.05 to 0.46 for various tail-cone positions over the entire operable range of engine speeds. The characteristics of the turbine are presented as functions of the total-pressure ratio across the turbine and the turbine speed and the gas flow corrected to NACA standard atmospheric conditions at sea level. The effect of changes in altitude, flight Mach number, and tail-cone position on turbine performance is discussed. The turbine efficiency with the tail cone in varied from a maximum of 80.5 percent to minimum of 75 percent over a range of engine speeds from 7500 to 17,500 rpm at a flight Mach number of 0.055. Turbine efficiency was unaffected by changes in altitude up to 15,000 feet but was a function of tail-cone position and flight Mach number. Decreasing the tail-pipe-nozzle outlet area 21 percent reduced the turbine efficiency between 2 and 4.5 percent. The turbine efficiency increased between 1.5 and 3 percent as the flight Mach number changed from 0.055 to 0.297.
Date: January 8, 1947
Creator: Krebs, Richard P. & Suozzi, Frank L.
Partner: UNT Libraries Government Documents Department

Investigation of Turbine of Mark 25 Torpedo Power Plant with Five Nozzle Designs

Description: Efficiency investigations were made on the two-stage turbine from a Mark 25 aerial torpedo to determine the performance of the unit with five different turbine nozzles. The output of the turbine blades was computed by analyzing the windage and mechanical-friction losses of the unit. A method was developed for measuring the change in turbine clearances with changed operating conditions. The turbine was found to be most efficient with a cast nozzle having a sharp-edged inlet to the nine nozzle ports.
Date: October 8, 1947
Creator: Hoyt, Jack W. & Kottas, Harry
Partner: UNT Libraries Government Documents Department

Air-Stream Surveys in the Vicinity of the Tail of a 1/8.33-Scale Powered Model of the Republic XF-12 Airplane

Description: The XF-12 airplane was designed by Republic Aviation Corporation to provide the Army Air Forces with a high performance, photo reconnaissance aircraft. A series of air-stream surveys were made n the vicinity of the empennage of a 1/8.33-scale powered model of the XF-12 airplane in the Langley 19-foot pressure tunnel. Surveys of the vortical-tail region were made through a range of yaw angles of plus or minus 20 degrees at a high and low angle of attack. The horizontal-tail surveys were made over a fairly wide range of angles of attack at zero degrees yaw. Several power and flap conditions were investigated. The results are presented in the form a dynamic pressure ratios, sidewash angles, and downwash angles plotted against vertical distance from the fuselage center line. The results of the investigation indicate that a vertical tail located in a conventional position would be in a field of flow where the dynamic pressure ratios at the horizontal tail to be increased; for equal lift coefficients, the effect of power or flap deflection on the direction of flow at any particular point in the region of the horizontal tail is small.
Date: April 8, 1947
Creator: Foster, Gerald V.
Partner: UNT Libraries Government Documents Department

Altitude performance and operational characteristics of 29-inch-diameter tail-pipe burner with several fuel systems and flame holders on J35 turbojet engine

Description: An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning has been conducted in the NACA Lewis altitude wind tunnel. Several fuel systems and flame holders were investigated in a 29-inch-diameter tail-pipe burner to determine the effect of fuel distribution and flame-holder design on tail-pipe-burner performance and operational characteristics over a range of simulated flight conditions. At an altitude of 5000 feet, the type of flame holder used had only a slight effect on the combustion efficiency. As the altitude was increased, the decrease in peak combustion efficiency became more rapid as the blocking area of the flame holder was reduced. At all altitudes investigated, an improvement in the uniformity of the radial distribution of fuel and air slightly increased the peak combustion efficiencies and shifted the peak combustion efficiency to higher tail-pipe fuel-air ratios. The use of an internal cooling liner extending the full length of the tail-pipe combustion chamber provided adequate shell cooling at all flight conditions investigated.
Date: November 8, 1949
Creator: Conrad, E William & Prince, William R
Partner: UNT Libraries Government Documents Department

Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms July 12, 1947 to July 18, 1947 at Clinton County Army Air Field, Ohio

Description: The gust and draft velocities from records of NACA instruments installed in P-61c airplanes participating in thunderstorm flights at Clinton County Army Air Field, Ohio, from July 12, to July 18, 1947 are presented.
Date: December 8, 1947
Creator: Funk, Jack
Partner: UNT Libraries Government Documents Department