How the Rotary Pulse Jet compares with an IC Piston Engine: 2

Power developed by a Rotary Pulse Jet Engine:
The total pressure developed by a Rotary Pulse Jet Engine with a cylindrical combustion chamber (rocket pod) having a volume of 9" and a back wall diameter of 2.5" is ideally 1.25² x 3.14 x 500 = 2453lbsf, since both combustion chambers fire at the same time, the total pressure available during a single power stroke should be 2453 x2 or 4906 lbsf approximately. However, just as in the IC Engine, the slow rate of speed of the flame front means that it is not always possible to utilise the full power of the engine because the rotor is rotating faster than the fuel burns ! When I had first proposed this idea, many critics had suggested that the combustion chamber would simply explode under the combined pressure of 500 psi and a temperature of 2000^{0 Centigrade.}under the mistaken impression that the CDN valve would not be able to open quickly enough. In actual fact the problem is to forward the ignition enough to enable the ignition process to get started before the CDN valve is opened The CDN valve which is activated by a cam on the inside of the outer housing cover of the rotor has to travel only 1/2 an inch before being activated. If the rotor has a diameter of 10" then its circumference is 31.4 inches and the time taken to travel half an inch at 1500 rpm would be 1500/60 = 25 or 25 x 31.4" in one second = 785" therefore the time taken for the CDN valve to fully open is only about 1/1570 sec which is extremely fast. However thanks to advanced electronics the ignition can be timed so that it gives the maximum power for any rpm, the point at which the CDN valve opens, naturally remaining fixed. Once the CDN valve is fully opened it takes only about 1/1500 of a second for the combustion chamber to fully exhaust all the gases in it, thus timing is vital. However the great advantage of the Rotary Pulse Jet Engine is the amount of torque that it can develop. Torque is everything in a car engine, it represents the amount of power available for turning the main shaft. In the piston engine, as you had seen on the last page, much of the power is dissipated because of the presence of a crankshaft, in the rotary pulse jet engine , there is no such dissipation and practically all of the power available is in the form of torque. Imagine an axle attached to a lever one foot long, if one pound of pressure is applied to the lever it represents one foot pound of torque at the axle. Conversely imagine the same axle with the lever attached at its mid-point to the axle if one pound of force is applied simultaneously to both ends of the lever in the direction of rotation, the resultant is again one foot pound of torque being exerted on the lever. Having two combustion chambers firing simultaneously thus gives twice the torque of a single combustion chamber firing. Thus even though the initial power exerted by the RPJ might be smaller than that of a piston engine, the torque that it exerts would be much greater, making it much more efficient. Thus if the rocket pods combustion chambers work at 70% efficiency i.e 0.7 x 4906 = 3434 ft lbs all of which is available as torque, compare this with the 160 foot pounds of torque generated by the Chevy v-8 on the last page ! Of course these figures represent the maximum possible power, in practical conditions the power developed might be considerably less, but is is still a great improvement on the IC piston engine. The generation of such a large amount of torque actually results in fuel saving because this torque can be used to rotate a fly-wheel at a three to one gearing ratio, making it possible for the Rotary Pulse Jet Engine to work only intermittently while the fly-wheel carries most of the load ! This is rather the same principle used to work toy cars, the fly-wheel is revved up and then does the rest of the work. This would be quite impossible to do with a IC piston engine because of the need for linear to rotary conversion. The fly-wheel could be linked to the RPJ via a CVT continuously variable transmission and the RPJ would automatically switch on as the Flywheel energy reached critical levels. Alternatively , the RPJ could be connected to three auragen alternators in series giving a total output of 24 KW and run as an electric car ! The auragen alternator has been extensively tested by the US military for the past 8 years, has seen service in Iraq and Afghanistan and is absolutely dependable. Here again the flywheel would do its part, the invaluable advantage of this is that flywheels are used at ordinary speeds, around 7000rpm to 10000rpm there is therefore no risk of catastrophic failure as would result with flywheel speeds in excess of 50,000rpm as has been the general trend in recent years. The RPJ can extract power from flywheels at relatively low rpm, this is a great advantage over conventional piston engines. The maximum efficiency of the Rotary Pulse Jet Engine is when it is functioning between 1500 rpm and 3000 rpm, however this is hardly a disadvantage, the much vaunted and talked about Wankel engine has a maximum of only 1200 rpm! Yet it is able to work so well because the main shaft is geared at a 3:1 ratio to the turning of the rotor, thus the main shaft turns three times to the rotors one, this is possible because of the high torque generated by the Wankel engine. Further it is possible to use lower octane fuels to reduce the time during which the fuel combusts.
Why the Rotary Pulse Jet Engine will work:
If one looks dispassionately at an IC piston engine it is possible to see that in many respects it resembles a gun. With the cylinder forming the barrel, the piston the projectile and the fuel air mixture the propellant. Yet the bullet (piston) is fired only a distance of 3" or so down the barrel before it comes to a halt, this in itself shows the inherent inefficiency of an IC piston engine! By contrast the Rotary Pulse Jet engine is free to rotate to the maximum limit of its rotation. The reason that the Rotary Pulse Jet Engine will work is because of the manner of working of a recoilless rifle. For those who are interested there is a good article about recoilless rifles available at Wikipedia. In a recoilless rifle the breech of the gun is replaced by a ventura or convergent divergent nozzle, thus when the gun is fired the gases of the propellant combusting are ejected through the venturi at great velocity, propelling the projectile out of the barrel in an equal and opposite reaction, thereby cancelling out the forces of recoil. Despite the fact that a normal gun works by the pressure caused by the expansion of gases in a sealed barrel and the recoilless rifle works by ejecting those gases at velocity, the recoilless rifle has an efficiency almost similar to that of a normal canon, firing a similar caliber shell. The Rotary Pulse Jet Engine should be even more efficient because the gases are put under pressure before being ejected. Therefore it follows that the power developed by a Rotary Pulse Jet Engine should be equivalent to that of an IC piston engine having a similar size combustion chamber.

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