Report presenting static tests on the compatibility of gaseous fluorine with various liquids, solid plastics, waxes, and greases at pressures of 0 and 1500 pounds per square inch gage and atmospheric temperature. Several materials were found to be compatible at atmospheric pressure, but only Teflon and ruby were compatible under static conditions at 1500 pounds per square inch gage.

"An investigation of the isothermal wake-flow characteristics of several flame-holder shapes was carried out in a 4- by 4-inch flow chamber. The effects of flame-holder-shape changes on the characteristics of the Karman vortices and thus on the recirculation zones to which experimenters have related the combustion process were obtained for several flame holders. The results may furnish a basis of correlation, of combustion efficiency and stability for similarly shaped flame holders in combustion studies" (p. 1).

Report discusses the results of an investigation into the aerodynamic characteristics of models of a tailless, pursuit-type, supersonic airplane employing a wing of triangular plan form. Measurements of lift, drag, and pitching moment, side force, drag, and yawing moment are described for several angles of attack and angles of yaw. Information about elevator and rudder behavior is also described.

Memorandum presenting a brief method for estimating the speed response of turbojet and turbine-propeller engines to a step change in fuel flow. The method approximates the dynamic equilibrium in the gas-turbine engine with a first-order linear differential equation, the time constant of which varies inversely with the equilibrium speed. Engine time constants computed by means of this method are compared with time-constant data obtained by direct measurement of transient on three turbojet engines and two turbine-propeller engines.

Report presenting an experimental investigation on a single turbojet engine combustor and on a turbojet engine using a fuel mixture of 70 percent trimethyl borate and 30 percent methyl alcohol. Results regarding the single combustor's deposition, combustion efficiency, ignition, temperature distribution, pressure drop and the engine operation are provided.

"An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of a flying-boat hull of a length-beam ratio of 15 in the presence of a wing. The investigation was an extension of previous tests made on hulls of length-beam ratios of 6, 9, and 12; these hulls were designed to have approximately the same hydrodynamic performance with respect to spray and resistance characteristics. Comparison with the previous investigation at lower length-beam ratios indicated a reduction in minimum drag coefficients of 0.0006 (10 percent) with fixed transition when the length-beam ratio was extended from 12 to 15" (p. 1).

Static tests on the compatibility of fluorine with non-metals at atmospheric temperature eliminated many materials from further consideration for use in fluorine systems. Several materials were found compatible at atmospheric pressures. Only Teflon and ruby (aluminum oxide) were compatible at 1500 pounds per square inch gage.

"An investigation of the XJ-41-V turbojet-engine compressor with a revised vaned collector was conducted to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal compressors of this type. The original vaned collector was revised by increasing the flow area at the vaned collector entrance. A maximum adiabatic efficiency of 0.81 was obtained at a corrected weight flow of 36.5 pounds per second and a pressure ratio of 1.90" (p. 1).

One-dimensional mean-section flow and blade specific losses proportional to average specific kinetic energy are assumed in the analysis. Range of the work-speed parameter lambda considered includes low to moderate blade speeds with high specific work outputs, where critical turbojet, turbopump, and accessory-drive turbines are encountered. A diffusion factor of 0.5 limits the loading on the downstream stators. Turbine efficiences considered are total or aerodynamic, rating, and static. Efficiences of velocity-diagram types at impulse and that corresponding to values of maximum efficiency are presented and compared to indicate in what range of lambda downstream stators are beneficial as well as the attending improvements in efficiency.