From Introduction: "The results of varying only Reynolds number for several equivalent tip speeds are presented and probable reasons for the apparent variation of adiabatic efficiency with inlet temperature are discussed."

From Introduction: "The design and flight evaluation of an airborne target simulator for use in tracking studies of fighter-type airplanes equipped with optical gunsights have recently been reported (ref. 1). In this equipment the target airplane was represented by a movable dot of light projected on the windshield of the test airplane."

The following report covers an investigation that was done to supplement available experimental data on flow fields behind wings of an aircraft at supersonic speeds, as well as to furnish more quantitative information on the choice of the theoretical method for a given configuration and the accuracy to be expected when using such a method.

"The data presented in this report are part of a general program to determine the effects of xylidines on the knock-limited performance of currently used aviation fuels" (p. 2).

This report is a revision of the altitude pressure tables of the United States standard atmosphere given in Technical Report No. 246 and the altitude range has been extended from 50,000 to 80,000 feet.

From Introduction: "The data included in this report for Nimonic 80A alloy, for instance, represent experiments carried out to help clarify a production problem of grain-size control in an alloy which has been extensively used. The general procedure of the investigation was to carry out controlled laboratory experiments on samples of bar stock to find conditions of heating and hot-working which resulted in abnormal grain growth."

Report discussing the 6-foot-4-inch wind tunnel and its auxiliary equipment has proven itself capable of continuous and reliable output of data. The real value of the tunnel will increase as experience is gained in checking the observed tunnel performance against full-scale performance. Such has been the case of the 8- by 8-foot tunnel, and for that reason the comparison in the calibration tests have been presented.

From Introduction: "Thrust augmentation of an axial-flow-type turbojet engine by burning fuel in the tail pipe is discussed in references 1 to 3. Thrust augmentation of the same turbojet engine by water injection at the compressor inlet is reported in reference 4."

From Introduction: "An apparatus that gives a quick and an accurate measurement of the rate of discharge has been has been designed by the NACA and is described in this report."

Memorandum presenting measurements of gust and draft velocities within cumulus clouds at a certain army air field using an AT-6 airplane. The measurements were made to supplement the at a obtained with P-61C airplanes. The data are summarized in tables.

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 August 7, 1947 to August 13, 1947 are presented.

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 August 16, 1947 to August 20, 1947 are presented.

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.

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 June 2, 1947 to June 7, 1947, are presented.

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 June 11, 1947 to July 11, 1947 are presented.

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 September 4, 1947 to September 5, 1947 are presented.

From Introduction: "Experimental investigations (reference 1) have shown that in some cases the thrust can be more than doubled by means of tail-pipe burning. A comparison is made of a standard turbojet engine, whose thrust is augmented by tail-pipe burning, and a ram-jet engine. The performance characteristics for the ram-jet engine were computed entirely from theoretical considerations and on the assumption that the burner-inlet velocity was constant."

From Introduction: "The experiments in high-speed flow showed that an intense, high-frequency acoustic radiation is an essential feature of the problem. Consequently, a study of the acoustic field (involving schlieren observations and frequency and intensity measurements) was undertaken. This report presents the salient features of the study, which was mainly exploratory."

Report presents the results of tests conducted at Stanford University of a 3-foot model propeller at four pitch settings and at 0 degree, 10 degrees, 20 degrees, and 30 degrees yaw.

Note presenting methods for ascertaining the value of n in Euler's simplified formula, which can be used for the compressive strength of tapered airplane struts, by estimating from curves and by calculation.

From Summary: "Data are included on the amount of fallout from the cloud and the concentration of boric oxide in the cloud."

From Summary: "This report presents the aerodynamic measurements made during a Navy investigation conducted in the Langley 8-foot high speed tunnel to determine the actual human tolerance to wind blasts."

From Introduction: "The difficulties experienced in cooling the exhaust-valve seats of the rear-row cylinders have been overcome to a considerable extent by improving the mixture distribution through application of the injection impeller (reference 1) and by augmenting the flow of cooling air to the critical baffles (reference 2). Flight tests of this airplane (reference 3) indicated that the temperatures of exhaust-valve seats on rear-row cylinders were markedly lowered by these modifications and that airplane range, altitude, and gross weight previously limited by these temperatures could be greatly increased."

From Introduction: "In the present report, consideration is given to certain features intended to improve the accleration-limiting characteristics of a normal-accleration control system."