Report discussing a model of a delta-wing configuration with four engines mounted two to a nacelle below the wing that was tested a variety of Mach numbers and Reynolds numbers. The wing static-pressure coefficients, wing pressure coefficients, and lift coefficient of different configurations are described.

From Introduction: "The objective of this report are (1) to describe the complete fuel system, (2) to discuss the procedure used for transitions between JP-4 fuel and hydrogen, and (3) to present and discuss engine performance obtained with both fuels, and (4) to review the reliability of the fuel system."

Report presenting an investigation of a liquid-hydrogen fuel system developed to operate one of the turbojet engines in a twin-engine light bomber at an altitude of 50,000 feet and Mach number 0.75. The heat exchanger was evaluated in an altitude test chamber in conjunction with the complete aircraft fuel system. Results regarding calculated heat-exchanger performance, experimental heat-exchanger performance, and reliability are provided.

Memorandum presenting the system analysis, design, and performance of a control system for an experimental flight-type hydrogen fuel system. The fuel system was designed to investigate some of the problems associated with the utilization of hydrogen as an aircraft fuel. Speed control of the engine was obtained by coupling the hydrogen regulator to the JP-4 fuel control.

Memorandum presenting testing of a twin-engine light bomber modified to utilize hydrogen fuel in one of the two engines during flight at an altitude of 50,000 feet. Three completely successful flights were made using hydrogen fuel. Data are presented to show the effect of tank agitation on fuel pressure and fuel losses.

Note presenting an investigation at low speed of the performances of circular and annular 90 degree bends of simple shapes conducted for configurations for which the cross-sectional area was constant, expanding, and contracting. Two series of transition bends were included, in which the transition occurred upstream of the bend, within the bend, and downstream from the bend. Results regarding the inlet velocity profiles, exit velocity and total-pressure profiles, and mean total-pressure-loss coefficients and exit total-pressure distortions are provided.

Report presenting linearized-theory calculations of the drag reduction achieved by applying the first three terms of a power series for twist to flat delta wings. For the family of wings investigated, the maximum drag reduction is 2 percent in the medium sweepback range with a steady diminution in both directions. Results for the delta and arrow wings and the optimum settings are provided.

Report presenting the results of an experimental and theoretical investigation of the vaporization of fuel droplets in heated air under atmospheric pressure. An experimental investigation of the temperature and mass histories of single droplets was made, a comparison of the experimental results was conducted with calculated temperature and mass histories, and the time taken by a droplet vaporizing to for a mixture of fuel vapor and air of combustible strength is calculated.

Report presenting an investigation at low speed to determine the Magnus effect on various sections of a body of revolution of which several sections could be rotated either as individual units or in combinations. The investigation included the measurement of the Magnus effect on the body alone and on the body with a three-blade propeller.

Report presenting an approximate analysis of the nonlinear effects of initial twist and large deflections on the torsional stiffness of a cantilever plate subjected to a nonuniform temperature distribution. The results show that the initial twist and applied moments can have significant effects on the changes in stiffness produced by nonuniform heating. Results regarding the general results of equations and comparison with experiment are provided.

From Summary: "Results of rapid-heating tests of Inconel X sheet are presented for nominal temperature rates of 0.2 degrees F to 100 degrees F per second under constant tensile load conditions. Yield and rupture stresses obtained under rapid-heating conditions are compared with the results of conventional tensile stress-train tests at elevated temperatures. A marked increase in strength is observed with increased temperature rates."

Note presenting a method for determining lateral stability derivatives from flight measurements, which is obtained by arranging the lateral equations of motion in such form that information from each of the three modes of lateral motion may be utilized. The method permits determination of all the important derivatives without requiring an estimation of any of the derivatives. Results regarding the probable errors in measurements, errors in derivatives, effect of side-force rate derivatives, and some improvements in the method are provided.

Report presenting a study of the effects of wing flexibility on wing strains due to gusts for four spanwise stations of a four-engine bomber airplane and a correlation with previous testing results. Results regarding the power spectre, peak counts, amplification factors, statistical reliability, input disturbance, frequency-response functions, output response, and amplification factors are provided.

"By use of the linear theory of boundary-layer stability and Schlichting's formula for the maximum amplification of a disturbance, an approximate relation is derived between the Reynolds number on a cone and the Reynolds number on a flat plate for equal closeness to transition. The indication is that the ratio of the cone Reynolds number for transition, based on the distance to the cone apex, to the plate Reynolds number for transition, based on the distance to the leading edge, is not in general equal to 3, as has been suggested by other investigators, but varies from 3 when transition occurs at the minimum critical Reynolds number to unity when transition occurs at a large multiple of the critical Reynolds number" (p. 1).

Note presenting compressive stress-strain test results for 17-7 PH and AM 350 stainless-steel sheet in the heat-treated and annealed conditions for temperatures from room temperature to 1200 degrees Fahrenheit. Representative stress-strain curves are given for both materials at the test temperatures.

Note presenting the effect of reduced pressure on blowoff, flashback, and burning velocities of propane-oxygen-nitrogen burner flames were studied. The pressure exponent of burning velocity, 0.22, was nearly the same as for hydrogen-air flames; stability loops showed the same blowoff and flashback characteristics as were previously observed for hydrogen-air flames. Of the two system, the hydrogen-air system showed larger burning velocity, greater stability toward reduced pressure, and higher reaction order, and the propane-oxygen-nitrogen system showed the larger reactivity based on flashback.

Note presenting a flight-test investigation made on the control-line facility to determine the longitudinal stability and control characteristics of a model of a propeller-driven tail-sitter-type vertical-take-off airplane with delta wing during rapid transitions from hovering flight to forward flight and back to hovering. Results regarding transition from hovering flight to forward flight, transition from forward flight to hovering flight, and evaluation of control-line technique are provided.

Report presenting tests of a bomber and fighter airplane with experimental power control systems in order to explore some unsatisfactory control characteristics that seem to result from dynamic instability. The main explanation found in testing was the presence of static friction in the control valves of hydraulic-power control systems.

Report presenting a series of measurements made on the oscillating pressures near a tapered-blade-plan-form propeller at flight Mach numbers up to 0.72. Flight Mach number, power, and engine speed were controlled in an attempt to duplicate the conditions of a previous flight investigation. Results regarding effects of flight Mach number, effect of engine speed, and effects of engine power are provided.

"Available theories and test data on buckling of curved plates and shells are reviewed. For torsion and external-pressure loadings, the test data are correlated in terms of linear buckling theories for both the elastic and inelastic ranges. The cases which exhibit a marked disagreement between linear theory and test data include those of curved plates and cylinders under axial compression, cylinders under bending, and spherical plates under external pressure" (p. 1).

"A generalized crippling analysis for short monolithic panels with formed or extruded stiffeners is presented. Methods are presented for determining if riveted panels act in a monolithic manner and for determining the strength of those which do not. The failure modes of intermediate-length and long stiffened panels are discussed and methods given for estimating column strength. Theory and test data on optimum stiffened panels are presented and the various factors of importance in box types of construction are considered" (p. 1).

Available theories on failure of flat plates are reviewed, and test data on the postbuckling behavior, effective width, and failure of flat curved plates are correlated. Test data on the crippling strength of various formed and extruded shapes are reviewed, from which a generalized method of crippling analysis is formulated. This analysis is then applied to a variety of sections and materials in common use.

Note presenting a theoretical determination of minimum critical Reynolds numbers for laminar instability of two-dimensional stagnation flows over a wall cooled by normal fluid injection. The individual and net effects of wall temperature and normal fluid injection on the stability characteristics of the laminar boundary layer are investigated.

Report presenting testing demonstrating that fatigue cracks initiate in preexisting slip bands on planes parallel to planes from tests on large-grained specimens of 1100 and 5052 aluminum alloys. The resolved shear stress on the planes in crystal where fatigue cracks had developed were compared to uncracked crystals. Results regarding the location fatigue cracks, number of stress cycles observed, and differences of the crystals observed in the two types of aluminum alloys are provided.