Memorandum presenting an analysis of probable heat-exchanger weights for stationary and rotary regenerator heat exchangers for use in a hydrogen-expansion turbine engine. This is because rotary regenerators offer possibilities for a considerably lighter heat-exchanger core, possibly one-fourth that of the stationary regenerators.

Memorandum presenting a theoretical mixed-jet one-spool turbofan engine analyzed over a range of flight Mach numbers up to 2.95. The engine was characterized by an eight-stage fan-compressor unit. Results regarding performance maps, rotating stall, turbofan inlet axial velocity, and weight-flow variations are provided.

Performance characteristics of underslung vertical wedge inlet with porous suction at Mach numbers of 0.63 and 1.5 to 2.0.

Memorandum presenting an experimental and analytical study made at transonic speeds up to Mach number 1.43 to determine the ability of present calculation procedures to predict transonic drag-rise changes which result from physical model changes. Both wing-body and wing-body-tail configurations were investigated.

Memorandum presenting certain considerations and techniques pertinent to the application of the supersonic area rule to the design of airplane fuselages. Some of the factors considered are an extension of the rule to account for the interference effects of the wing and tail on the general flow field for asymmetrical configurations, the determination of fuselage area developments which result in approximately the minimum wave drag, and the influence of wing parameters and design Mach number on the effectiveness of fuselage shaping.

"Theoretical values of performance parameters for liquid ammonia and liquid fluorine as a rocket propellant were calculated on the assumption of equilibrium composition during the expansion process for a wide range of fuel-oxidant and expansion ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity" (p. 1).

"Theoretical values of performance parameters for liquid ammonia and liquid fluorine as a rocket propellant were calculated on the assumption of equilibrium composition during the expansion process for a wide range of fuel-oxidant and expansion ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity" (p. 1).

Memorandum presenting an instrument for recording and indicating the frequency and intensity of aircraft icing conditions to obtain statistical icing data over worldwide air routes during routine airline operations. Data of this type is needed to provide pertinent meteorological information necessary for the optimum design of ice-protection systems. The features that make this particular instrument desirable include the simplicity of operation, freedom from maintenance and operating problems, automatic operation upon encountering an icing condition, visual indications of icing intensity available to the pilot, total weight of 18 pounds, and continuous recorded data.

Report presenting an investigation of several wingless missile configurations for a range of Mach numbers to determine their lift, drag, and pitching-moment coefficients. Results for missiles having nose controls and missiles having tail controls are provided. The results were also compared to a conventional missile with wings.

Report presenting development tests on a model of the Republic F-105 airplane at a Mach number of 0.20. The purpose of the current investigation is to obtain the longitudinal force and moment characteristics of the model equipped with trailing-edge flaps of various spans and deflections. Results regarding the longitudinal stability characteristics and effect of the horizontal tail are provided.

Report presenting a flight investigation of a rocket-launched solid-fuel ram-jet engine designed to bypass cooling air around the fuel charge. The internally cooled combustor averted combustor burn-out during the flight test. Results regarding the net thrust coefficient, gross thrust coefficient, time history of the air specific impulse, and total fuel load are provided.

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.

Memorandum presenting an investigation of a can-type flame holder employing a fuel-air-mixture control sleeve in a 20-inch-diameter ramjet combustor conducted by free-jet and direct-connect techniques at a simulated flight Mach number of 3.0 and altitudes from about 70,000 to 80,000 feet. Results regarding the effect of shortening combustion chamber and effect of pilot-burner variables are provided.

Memorandum presenting an investigation of the effect of the number and width of annular flame-holder gutters on afterburner performance in a 26-inch-diameter afterburner test rig. The burner inlet temperature was held at 1250 degrees Fahrenheit. Results regarding the effect of gutter width on stability limits and effect of flame-holder blockage on pressure drop are provided.

Report presenting an investigation of the effects of afterburner-inlet total temperature, total pressure, velocity, fuel-air ratio, and afterburner combustion-chamber length on afterburner performance and stability limits using a cylindrical afterburner installed in a duct test rig. The afterburner was investigated over a range of total temperature, total pressure, velocity, and afterburner fuel-air ratios.

Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord. Results regarding the leading-edge radius effects and maximum thickness-chord ratio are provided.

Memorandum presenting an investigation conducted in the 4- by 4-foot supersonic tunnel to determine the longitudinal stability and control characteristics of a model of a supersonic airplane configuration at Mach number 1.40. The model had a 40 degree sweptback wing with 10-percent-thick circular-arc sections normal to the quarter-chord line. The results indicated a high degree of longitudinal stability that was fairly constant throughout the trim-lift-coefficient range.

Report presenting a correlation of carbon deposition of 19 fuels in a turbojet combustor as a function of the boiling point and of the flame height at the sooting point of the fuels in a simple wick lamp for a particular combustor operating at a single set of conditions. Two similar investigations with different combustors, operating conditions, and nine different fuels yielded similar correlations on the same graph.

Report presenting the results of tests of four model wings of aspect ratios 1, 2, 4, and 6 and with NACA 65(sub 1)-210 sections. The experimental lift-curve slope is compared with predictions from theory. Results regarding lift, drag, and pitching moment, lift-curve slope, drag divergence, minimum drag, and pitching moment are provided.

Report presenting an investigation in the altitude wind tunnel to determine the operational characteristics of a J47 turbojet engine over a wide range of simulated flight conditions at a range of altitudes. Operational characteristics investigated include operating range, starting, altitude and airspeed compensation of the fuel regulator, and acceleration.

Data are presented for the fundamental flame velocities of 10 pure alkadienes that have isolated, conjugated, or cumulative double-bond systems. On the basis of this limited amount of data and the flame velocities previously reported, it is concluded that unsaturation changes the flame velocity in the order alkanes ? alkenes ? alkadienes with isolated double bonds ?= alkadienes with conjugated double bonds ? alkadienes with cumulative double bonds ?= alkynes. There were no significant differences in the flame velocities of cis and trans 1,3-pentadiene. The alkadienes 1,2-pentadiene and 2,3-pentadiene, with different positions of the cumulative double bond in the straight chain, have similar flame velocities. Methyl substitution in a hydrocarbon reduces the flame velocity; the extent of the reduction increases with the degree of unsaturation of the hydrocarbon.

Report presenting a review of the present status of research and development on high-energy fuels for ramjet propulsion. It also presents experimental investigations on the use of high-energy fuels in ram jets that include the materials aluminum, boron, boron hydrides, carbon, coal and coal-light metal compositions, liquid hydrogen, and magnesium. A comparison of the fuels in terms of heating values, combustion temperatures and specific impulse, and availability of fuels are provided.

Report presenting a method of generating variable Mach number supersonic flow in a channel of fixed geometry by the removal of air through uniform porous walls. Calculated porosity distributions are presented for several minimum-length nozzles designed to operate at Mach numbers up to 2.0. Experimental and analytical data is presented.

Report presenting an experimental investigation of thrust augmentation by bleedoff using a 4000-pound-thrust turbojet engine at zero flight-speed, sea-level conditions. Secondary combustion air was bled off from combustion chambers and discharged from an exhaust nozzle and water was then injected into the combustion chambers to replace the bleed-off air. Results regarding the thrust characteristics, engine power, and augmented thrust ratio are provided.