Van Nostrand's engineering magazine . hus adding to the rate ofignition the mechanical disturbance pro-duced by the entering flame. Ho hassucceeded by this means in producingmaximum pressure in one-hundredthpart of a second in a space containing200 cubic inches. This rate of ignitionis too rapid, and would not give the en-gine time to take up the slack in bearings,connecting rods, Sec. But by firing amixture with varying amounts of mechan- the exhaust valve to open. This mayhappen from several causes, a too dilutedmixture, or too little mechanical disturb-ance by the entering flame; or the ign
Van Nostrand's engineering magazine . hus adding to the rate ofignition the mechanical disturbance pro-duced by the entering flame. Ho hassucceeded by this means in producingmaximum pressure in one-hundredthpart of a second in a space containing200 cubic inches. This rate of ignitionis too rapid, and would not give the en-gine time to take up the slack in bearings,connecting rods, Sec. But by firing amixture with varying amounts of mechan- the exhaust valve to open. This mayhappen from several causes, a too dilutedmixture, or too little mechanical disturb-ance by the entering flame; or the igni-tion may be missed until the pressurebegins to fall by the forward movementon the piston, when the rate of inflamma-tion begins to come more nearly to Mal-lards number of 11 inches per slow combustion, or rather slow in-flammation, is to be avoided in the gas• engine. Every effort should be made to! secure complete inflammation as soon! after ignition as is practicable. The linesin the diagram show this very clearly ;. COMPRESSION GAS ENGINE. ical disturbance almost any time of igni-tion can be obtained between -j-J-g- and y1^of a second. It does not matter whetherthe mixture used is rich or weak in gas;the rich mixture can be fired slowly andthe weak one rapidly, just as may be re-quired. The rate of ignition of thestrongest possible mixture is so slow thatthe time of attaining complete inflamma-tion depends on the amount of mechani-cal disturbance permitted. Fig. 9, a diagram from an Otto engine,shows what happens in a compressionengine of type 3 when the ignition comeslate and the movement of the pistonoverruns the rate of the spread of theflame. It is then seen that the maximumpressure is not attained until far on inthe stroke, and as a consequence greatloss of power results, the pressure at-taining its maximum when it is time for the normal lines are those in which the riseis almost straight up from the point ofthe beginning of the ignition ; they aremarked
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectenginee, bookyear1879
