Llamas with Hats
Posted: Mon Apr 12, 2010 4:17 pm
Sitting in the garage, wondering why Llamas with Hats is so damn funny, I had an epiphany:
If a pulsejet's cycling draws in fresh air to ingnite the new fuel air charge, then why couldn't we do the same to vent a basic metered-propane combustion launcher?
We all pretty much understand; That when the fuel/air mixture is ignited... as the gas expands and the combustion chamber empties, the pressure inside the Combustion Launcher drops. Due to inertia of the moving gas, this drop continues for some time even after the pressure falls back to atmospheric. The expansion stops only when the momentum of the gas pulse is completely spent. At that point, there is a partial vacuum inside the Combustion Launcher.
The process can now reverse itself. The outside (atmospheric) pressure is now higher than the pressure inside the engine and fresh air can rush into the end with the PVC Check Valve.
The words from the last 2 paragraphs, were copied and pasted out of a pdf file about Valveless Pulsejets, which was created by Bruno Ogorelec. The words were edited to fit the current application of a new Combustion Launcher design concept.
It may take quite a bit of experimenting to find an ideal C:B ratio, such as the "general rule-of-thumb 0.7:1" for most basic metered-propane combustion launchers. But, how cool would it be to have a launcher that now requires no (additional) lapse in the reloading sequence, to vent the chamber?
My idea is:
If the check valve were mounted so that the flow was towards the inside of the combustion chamber, then perhaps the 14.7 pounds per square inch of force would be more than sufficient to overcome the spring pressure in the check valve and allow fresh air to be drawn in?
Starting with a 0.7:1 C:B ratio, the barrel can be progressively shortened, until the tester experiences a noticeable reduction in performance... Much like Latke' did in his testing.
If a pulsejet's cycling draws in fresh air to ingnite the new fuel air charge, then why couldn't we do the same to vent a basic metered-propane combustion launcher?
We all pretty much understand; That when the fuel/air mixture is ignited... as the gas expands and the combustion chamber empties, the pressure inside the Combustion Launcher drops. Due to inertia of the moving gas, this drop continues for some time even after the pressure falls back to atmospheric. The expansion stops only when the momentum of the gas pulse is completely spent. At that point, there is a partial vacuum inside the Combustion Launcher.
The process can now reverse itself. The outside (atmospheric) pressure is now higher than the pressure inside the engine and fresh air can rush into the end with the PVC Check Valve.
The words from the last 2 paragraphs, were copied and pasted out of a pdf file about Valveless Pulsejets, which was created by Bruno Ogorelec. The words were edited to fit the current application of a new Combustion Launcher design concept.
It may take quite a bit of experimenting to find an ideal C:B ratio, such as the "general rule-of-thumb 0.7:1" for most basic metered-propane combustion launchers. But, how cool would it be to have a launcher that now requires no (additional) lapse in the reloading sequence, to vent the chamber?
My idea is:
If the check valve were mounted so that the flow was towards the inside of the combustion chamber, then perhaps the 14.7 pounds per square inch of force would be more than sufficient to overcome the spring pressure in the check valve and allow fresh air to be drawn in?
Starting with a 0.7:1 C:B ratio, the barrel can be progressively shortened, until the tester experiences a noticeable reduction in performance... Much like Latke' did in his testing.