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The ram accelerator has a huge downfall. The velocity of the projectile must be at least 500m/s on entry, any less and there will be little or no ramjet effect. The barrel and projectile design is also crucial

inonickname wrote:The barrel and projectile design is also crucial

Not related to the ram accelerator but this is a crucial point in accounting for the performance of the V3. August Cönders, the man who championed the project worked for the Röchling company that was also responsible for an armour piercing "bunker buster" working on the same principle as an APFSDS shell. When fired from a conventional gun, it was capable of exceptional performance.

The shell could pass through 3 meters of earth, 36 meters of concrete, a layer of broken stone, a gun casement, and into the floor beneath with ONE shot!!!

The shell fired by the V3 was of similar design, though the point was to have it cut efficiently through the air as opposed to fortifications.

inonickname wrote:The ram accelerator has a huge downfall. The velocity of the projectile must be at least 500m/s on entry, any less and there will be little or no ramjet effect. The barrel and projectile design is also crucial

References please.. on ram accelerator.

I'm looking at some benefit even at below SOS causing rapid compression for hot light heated air at SOS in the transition zone which then expands above SOS in the barrel. I would much like to view and study your reference on 500 m/s minimum.

A ram accelerator is basically a ramjet. Ramjet's require high velocities to even begin functioning as a ramjet properly, hence why anything using a ramjet will be a hybrid with another propulsion means to get it up to velocity.

It was in a PDF which was posted here a while ago. Probably in this thread.

inonickname wrote:A ram accelerator is basically a ramjet. Ramjet's require high velocities to even begin functioning as a ramjet properly, hence why anything using a ramjet will be a hybrid with another propulsion means to get it up to velocity.

It was in a PDF which was posted here a while ago. Probably in this thread.

A ramjet needs to get enough input to provide the compression stage like any jet engine or combustion engine. With no compression they don't work as an engine. For air to be the mass projectile on the inlet, high speed is required. When compressing air with a projectile with considerably more mass than air (the piston) it can move much slower and still provide compression. The reduction of cross sectional area and energy given up by the deceleration of the piston provides the energy required for the compression.

I'm just using air as spring to transfer energy between a slower larger mass to a smaller mass. The area transition acts as a lever changing slow large cross section flow into small cross section high speed flow. High compression is not required to make this work.

It is not an air ram. It's a piston driven compression air ram.

IT WON'T WORK! Make an amplified combustion or multi-mix combustion instead!!!!

Moonbogg wrote:IT WON'T WORK! Make an amplified combustion or multi-mix combustion instead!!!!

I'll post results after I build it. Then we can decide if it works. I'm not building a multi stage, but am working on the math for a cannon driving a piston which drives a air ram. Goal, supersonic marshmallow.

I meant multi stage combustions will be inefficient and not work, at least not as hoped for.

Found this little clip related to the V-3, it's in German but some nice visuals and CGI.

[youtube][/youtube]