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National advisory committee for aeronautics
Jan., I93I.]
BOOK R E V I E W S .
I29
of repeated networks and some generalizations of "["and II sections. The remaining chapters are concerned chiefly with extensions or applications. They include such subjects as Filters, Homographic Transformation, Coil Loaded Telephone Cable and Multistage Amplifier. The book is quite mathematical in nature and is well supplied with illustrations. T. K. CLEVELAND, NATIONAL ADVISOR*/" COMMITTEE FOR AERONAUTICS. Report No. 359. An Investigation of the Effectiveness of Ignition Sparks. By Melville F. Peters, Wayne L. Summerville and Merlin Davis. I3 pages, illustrations, quarto. Washington, Government Printing Office, I93O. Price ten cents. The effectiveness of ignition sparks was determined by measuring the volume (or mass) of hydrogen and of oxygen which combines at low pressures. The sparks were generated by a magneto and an ignition spark coil. It was found t h a t with constant energy the amount of reaction increases as the capacitance component of the spark increases. The use of a series of spark gap may decrease or increase the amount of reaction, the effect depending upon the amount and the distribution of capacitance in the circuit. So far as the work has progressed, it has been found t h a t sparks reported by other investigators as being most efficient for igniting lean mixtures cause the largest amount of reaction. Differences between the amount of reaction with a magneto spark and an ignition spark coil were noted. The method appears to offer a means of determining the most efficient spark generator for internal-combustion engines as well as determining a relation between the character of spark, energy, and effectiveness in igniting inflammable mixtures. Report No. 36I. Experimental Determination of Jet Boundary Corrections for Airfoil Tests in Four Open Wind Tunnel Jets of Different Shapes. By Montgomery Knight and Thomas A. Harris. 27 pages, illustrations, quarto. Washington, Government Printing Office, I93O. Price twenty cents. The tests reported herein were conducted at the Langley Memorial Aeronaatical Laboratory, Langley Field, Va., to determine experimentally the instantaneous pressures at the discharge orifice of a common-rail fuel injection system in Which the timing valve and cut-off valve were at some distance from the automatic fuel injection valve, and also to determine the methods by which the pressure fluctuations could be controlled. The instantaneous pressures at the discharge orifice of a common-rail fuel injection system were determined by analyzing the stem-lift records of an a u t o . matic injection valve. The fuel injection was obtained by releasing fuel from a reservoir under high pressure by means of a cam-operated timing valve. The period of injection was controlled by the opening of a cam-operated by-pass valve which reduced the fuel p, essure between the timing valve and the injection valve. An injection system of this type assures the same rate of fuel discharge regardless of engine speed. The results show t h a t pressure wave phenomena occur between the high-pressure reservoir a n d the discharge orifice, but t h a t these pressure
BOOK R E V I E W S .
I29
of repeated networks and some generalizations of "["and II sections. The remaining chapters are concerned chiefly with extensions or applications. They include such subjects as Filters, Homographic Transformation, Coil Loaded Telephone Cable and Multistage Amplifier. The book is quite mathematical in nature and is well supplied with illustrations. T. K. CLEVELAND, NATIONAL ADVISOR*/" COMMITTEE FOR AERONAUTICS. Report No. 359. An Investigation of the Effectiveness of Ignition Sparks. By Melville F. Peters, Wayne L. Summerville and Merlin Davis. I3 pages, illustrations, quarto. Washington, Government Printing Office, I93O. Price ten cents. The effectiveness of ignition sparks was determined by measuring the volume (or mass) of hydrogen and of oxygen which combines at low pressures. The sparks were generated by a magneto and an ignition spark coil. It was found t h a t with constant energy the amount of reaction increases as the capacitance component of the spark increases. The use of a series of spark gap may decrease or increase the amount of reaction, the effect depending upon the amount and the distribution of capacitance in the circuit. So far as the work has progressed, it has been found t h a t sparks reported by other investigators as being most efficient for igniting lean mixtures cause the largest amount of reaction. Differences between the amount of reaction with a magneto spark and an ignition spark coil were noted. The method appears to offer a means of determining the most efficient spark generator for internal-combustion engines as well as determining a relation between the character of spark, energy, and effectiveness in igniting inflammable mixtures. Report No. 36I. Experimental Determination of Jet Boundary Corrections for Airfoil Tests in Four Open Wind Tunnel Jets of Different Shapes. By Montgomery Knight and Thomas A. Harris. 27 pages, illustrations, quarto. Washington, Government Printing Office, I93O. Price twenty cents. The tests reported herein were conducted at the Langley Memorial Aeronaatical Laboratory, Langley Field, Va., to determine experimentally the instantaneous pressures at the discharge orifice of a common-rail fuel injection system in Which the timing valve and cut-off valve were at some distance from the automatic fuel injection valve, and also to determine the methods by which the pressure fluctuations could be controlled. The instantaneous pressures at the discharge orifice of a common-rail fuel injection system were determined by analyzing the stem-lift records of an a u t o . matic injection valve. The fuel injection was obtained by releasing fuel from a reservoir under high pressure by means of a cam-operated timing valve. The period of injection was controlled by the opening of a cam-operated by-pass valve which reduced the fuel p, essure between the timing valve and the injection valve. An injection system of this type assures the same rate of fuel discharge regardless of engine speed. The results show t h a t pressure wave phenomena occur between the high-pressure reservoir a n d the discharge orifice, but t h a t these pressure