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Reduction of profile drag at supersonic velocities by the use of airfoil sections having a blunt trailing edge

Description: A preliminary theoretical and experimental investigation has been made on the aerodynamic characteristics of blunt-trailing-edge airfoils at supersonic velocities. The theoretical considerations indicate that properly designed airfoils with moderately blunt trailing edges can have less profile drag, greater lift-curve slope, and high maximum lift-drag ratio than conventional sections. These predictions have been substantiated by experimental measurements on airfoils of 10-percent-thickness ratio at Mach numbers of 1.5 and 2.0, and at Reynolds numbers between 0.2 and 1.2 million.
Date: September 1, 1955
Creator: Chapman, Dean R
Item Type: Report

A semi-empirical method for calculating the pitching moment of bodies of revolution at low Mach numbers

Description: A semiempirical method, in which potential theory is arbitrarily combined with an approximate viscous theory, for calculating the aerodynamic pitching moments for bodies of revolution is presented. The method can also be used for calculating the lift and drag forces. The calculated and experimental force and moment characteristics of 15 bodies of revolution are compared.
Date: May 17, 1951
Creator: Hopkins, Edward J
Item Type: Report

Investigation of stage performance of X24C-2 ten-stage axial-flow compressor at design speed

Description: The stage performance of the X24C-2 axial-flow compressor, as determined from radial distributions of total pressure and temperature measured in each stator-blade row, was investigated at design speed at weight flows corresponding to those of the maximum weight-flow, peak-efficiency, and surge points. The stage performance is presented as the measured stage pressure ratios and the calculated velocity diagrams. The average stage total-pressure ratio at the surge operating condition in the first stage was approximately 1.10; in the second stage, approximately 1.13; and in all remaining stages, approximately constant at a value of 1.15. Regions of inefficient flow are discussed so as to point out the reasons for the poor flow conditions.
Date: May 22, 1950
Creator: Finger, Harold B; Cohen, Leo & Stewart, Warner L
Item Type: Report