Describes precautions that should be taken when storing ear corn on the farm.

Note presenting an experimental study of the wet-surface temperature and stream conditions that result in ice-free surfaces for bodies in flight through icing clouds, and the results obtained are compared with values calculated using an analytical method. Two symmetrical airfoil models, one of diamond shape and the other of double-circular-arc contour, were used in the investigation. Results regarding the chordwise variation of pressure distribution, chordwise variation of recovery factor, the diamond airfoil, and circular-arc airfoil are provided.

"Results are presented of a free-flight investigation between Mach numbers of 0.7 to 1.3 and Reynolds numbers of 3.1 x 10(exp 6) to 7.0 x 10(exp 6) to determine the longitudinal aerodynamic characteristics of the Northrop MX-775A missile. This missile has a wing, body, and vertical tail, but has no horizontal tail. The basic wing plan form has an aspect ratio of 5.5, 45 deg of sweepback of the 0.406 streamwise chord line, and a taper ratio of 0.4" (p. 1).

A compilation of the six technical papers presented at the NACA Conference on Engine Stall and Surge on February 3, 1955 at the Lewis Flight Propulsion Laboratory. A list of conference attendees is also provided.

Report presenting external wave drag of bodies of revolution moving at supersonic speeds, which can be expressed either in terms of the geometry of the body or in terms of the body-simulating axial source distribution. The second of the methods is found to be more tractable.

Report presenting a study of the lubrication of steel by a series of stable fluorine- and chlorine-substituted methane and ethane derivatives. Several compounds containing fluorine and two or more chlorine atoms per molecule functioned as boundary lubricants to reduce friction and to prevent surface welding and metal transfer.

Note applying Stewartson's transformation to the laminar compressible boundary-layer equations and the requirement of similarity, resulting in a set of ordinary nonlinear differential equations previously quoted by Stewartson, but unsolved. The requirements of the system are specified. It is then transformed to an integral system with the velocity ratio as the independent variable.

Note presenting a determination of the spontaneous explosion limits of nine alkylsilanes as a function of temperature and fuel-air composition at a pressure of 1 atmosphere.

From Introduction: "This report presents a computational procedure which provides for the rapid and accurate calculation of any streamline in a series of special flows. Detailed information is given on the boundary conditions and equations used for computing the characteristic nets and stream function."

Note presenting an investigation of the intergranular corrosion of high-purity aluminum in hydrochloric acid studied as a function of iron content, heat treatment, and acid composition under conditions where the rate of intergranular penetration was of the order of 1 millimeter per week.

Report presenting a study of the wet-surface temperature and stream conditions that result in ice-free surfaces for bodies in flight through icing clouds and a comparison of these experimental results with calculated results using the analytical method. Two symmetrical airfoil models were used in the investigation and testing occurred for a range of Mach numbers and pressure altitudes. Results regarding chordwise variation of pressure distribution, chordwise variation of recovery factor, results with the diamond airfoil and circular-arc airfoil, and the experimental and analytical results are presented.

Report presenting an analysis of a method for determining pressure losses due to the flow of non-Newtonian materials in pipe lines by using basic flow data obtained from measurements of flow curves, which are rate-of-shear-shear-stress curves. Reported flow and pressure data are analyzed. The validity of the generalized friction diagram for describing flow of Bingham plastics in pipe lines is shown by an evaluation of experimental data of two independent investigators.

Note presenting an approximate thermal equation that was derived for quenching distance based on a previously proposed diffusional treatment. The quenching distance is expressed in terms of the thermal conductivity, the fuel mole fraction, the heat capacity, the rate of the rate-controlling chemical reactions, a constant that depends on the geometry of the quenching surface, and one empirical constant.

From Summary: "General quenching-distance equations were derived as extensions of the original simple theory of quenching by diffusion of active particles. These equations take into account the possibility of gas-phase chain breaking and branching and the effect of the efficiency of the walls to destroy active particles. The general characteristics of the equations were examined."

Report examining the use of transpiration cooling as a method to cool different structural elements such as turbine blades or the walls of combustion chambers in jet engines and parts of the skin of missiles. In some of the applications, the surface roughness inherently connected with a porous material may exceed the limit for which a surface is considered as hydraulically smooth.

Report presenting interferogram equations for calculating one-dimensional density distributions from optical-interference records, which are derived from generalized equations. The resulting evaluation equations are applicable for any plane of focus.

Report presenting an investigation of the ingestion of foreign objects by vortices formed between engine inlet and ground surface using a 5000-pound-thrust axial-flow jet engine. Pebbles were projected into the air by the vortices and were drawn into the engine by the high-velocity inlet-air stream.

Report presenting an exploratory study to determine whether a pilot could use vibration of the control stick as a means of maintaining a desired lift margin below the stall. Results regarding the ability of the subject to maintain a selected stick-shaker frequency and amplitude and ability of the subject to detect changes in frequency or amplitude are provided.

Note presenting an experimental investigation to study the behavior of full journal bearings under steady load when acted upon by a steady misaligning couple. Displacements of the ends of the journal axis relative to the bearing axis were measured with either an axial couple applied in the plane of the central load or a twisting couple in the plane normal to the central load. Results regarding the phenomena at zero central load, misaligned attitude, Sommerfeld number and capacity number, load ratio, and couple variable are provided.

"The manner in which flow in a boundary layer becomes turbulent was investigated on a flat plate at wind speeds generally below 100 feet per second. Hot-wire techniques were used, and many of the results are derived from oscillograms of velocity fluctuations in the transition region. Following a presentation of the more familiar aspects of transition, there are presented the very revealing facts discovered while studying the characteristics of artificially produced turbulent spots" (p. 853).

"As predicted by friction theory, experiments showed that friction and surface damage of metals can be reduced by solid surface films. The ability of materials to form surface films that prevent welding was a very important factor in wear of dry and boundary lubricated surfaces. Films of graphitic carbon on cast irons, NiO on nickel alloys, and FeO and Fe(sub 3)O(sub 4) on ferrous materials were found to be beneficial. Abrasive films such as Fe(sub 2)O(sub 3) or MoO(sub 3) were definitely detrimental. It appears that the importance of oxide films to friction and wear processes has not been fully appreciated" (p. 93).

From Summary: "This report treats the Kernel function of the integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for harmonically oscillating wings in supersonic flow. The treatment is essentially an extension to supersonic flow of the treatment given in NACA report 1234 for subsonic flow. For the supersonic case the Kernel function is derived by use of a suitable form of acoustic doublet potential which employs a cutoff or Heaviside unit function. The Kernel functions are reduced to forms that can be accurately evaluated by considering the functions in two parts: a part in which the singularities are isolated and analytically expressed, and a nonsingular part which can be tabulated."

"An investigation of the low-speed, power-off stability and control characteristics of a 1/10-scale model simulating the Convair F-102A airplane has been made in the Langley free-flight tunnel. The model in its basic configuration and with two modifications involving leading- edge slats and an increase in vertical-tail size was flown through a lift-coefficient range from 0.7 to the stall. Only relatively low-altitude conditions were simulated" (p. 1).

The lift on a bent, flat plate is calculated exactly by the use of conformal mapping. Results are presented in terms permitting direct determination of the angle of zero lift, the lift coefficient, and the lift-curve slope for any flap-chord ratio, flap-deflection angle, and angle of attack.