This document contains reproductions of the technical papers presented at the NACA - University Conference on Aerodynamics held at the Langley Aeronautical Laboratory on June 21, 22, and 23, 1948. The conference was held in recognition of the difficulties, imposed by security restrictions, in keeping abreast of the rapid advances in aerodynamics. The papers were prepared to review the status of a number of fields of interest, to summarize the more important wartime advances that are no longer classified, and to orient reference material for further study.

From Summary: "Four solid-propellant rocket engines of nominal 500-pound thrust were tested for starting characteristics at pressure altitudes ranging from 89,000 to 111,000 feet and at a temperature of -75^o F. Chamber pressures were measured on two of the runs. Average chamber pressures in these two runs were lower than expected, although action times agreed with the expected values."

Memorandum presenting equations for obtaining the wall coordinates of two-dimensional supersonic nozzles. The equations are based on the application of the method of characteristics to irrotational flow of perfect gases in channels. A brief discussion of characteristics as applied to nozzle design is given to assist in understanding and applying the nozzle-design method of the report.

Report presenting testing of seven models that from two different wing series: a series of taper ratio 0.5 and differing aspect ratio and a series of aspect ratio 4 and differing taper ratio. Measurements of lift, drag, and pitching moment were made at Mach number 1.53. The aerodynamic parameters generally varied with aspect ratio and taper ratio in the manner indicated by the linear theory.

Report discussing the effect of half-span and full-span split flaps through a deflection range on the low-speed, longitudinal characteristics of a sweptback wing with a round-nose, extensible leading-edge flap. Information about the effect of split-flap deflection on lift and stalling characteristics, effect of split flaps on gliding characteristics, and effect of leading-edge roughness on longitudinal stability is presented.

"Six numerical examples are presented for steady, two-dimensional, compressible, nonviscous flow in centrifugal compressors with thin straight blades, the center lines of which generate the surface of a right circular cone when rotated about the axis of the compressor. A seventh example is presented for incompressible flow. The solutions were obtained in a region of the compressors, including the impeller tip, that was considered to be unaffected by the diffuser vanes or by the impeller-inlet configuration" (p. 141).

Report presenting an investigation in the stability tunnel of the use of spoilers for obtaining static longitudinal stability of a model of a canard missile in reverse flight. Results indicated that stable pitching-moment slopes can be obtained at angles of attack up to 11 degrees in the low speed range of the tests, but further investigation of high subsonic speeds will be necessary.

Memorandum presenting an investigation of the effect of nozzle internal contour on afterbody drag in the 8- by 6-foot supersonic wind tunnel. Five different nozzle-afterbody configurations were evaluated. Results regarding the boattail pressure drag, base drag, and total drag are provided.

Report presenting an extension of previous work on immersed surfaces in the combustion zone of a ramjet engine. The primary focus was to determine the effect of combustion efficiency and stability of blades located within the immediate wake of a V-gutter flame holder and to find some location and orientation of blades for optimum combustion efficiency and improved stability limits with a minimum of pressure loss.

Memorandum presenting an analysis and evaluation of the meteorological requirements and problems anticipated with the operation of commercial turbojet aircraft. Discussions concerning problems of temperature, wind, pressure, ceiling, visibility, cloud and clear-air turbulence, icing, and communication are included in this study.

Memorandum presenting computation methods for analyzing turbojet-engine performance for a series of air-cooled nonafterburning and afterburning engines where all the engine components are simultaneously aerodynamically limited. The coolant-flow ratio was arbitrarily assigned so that the results of the analysis can be applied to any specific air-cooled blade configurations.

Report presenting an investigation of NACA 8.75-(5)(05)-037 eight- and six-blade dual-rotating propellers under static conditions. The slipstream-boundary cone angle was found to agree with the theoretical angle of spread for an unheated jet. Results regarding the longitudinal survey, stationary survey, effect of blade angle, nature of flow near propeller, and effect of blade angle on slipstream rotation are provided.

This is the second report giving the results obtained in the NACA 20-foot wind tunnel on the drag due to landing gears. The present report gives the results of tests of nonretractable and partly retractable landing gears intended for heavier low-wing monoplanes of the transport and bomber type.