I agree, amppatel. The mistake in assuming that momentum is the primary predictive indicator in penetration is that it is based on an errant postulate that penetration of animal tissues is modeled most effectively as a fluid and that drag forces are the primary resistive force encountered...
I don't think it's an overly simplistic proposition to identify animal tissue as either fluid or solid. Solids don't have to be hard or rigid in order to be a solid, by definition. I think what may be missing or going undisclosed is that the nature of penetration of fluid and solid are...
Actually, it IS required that there be a base assumption that the object is either fluid or non-fluid because the drag formula ONLY applies to an object moving through a fluid and actually the core argument is whether or not it is drag that is primarily responsible for stopping an arrow as it...
Am I to assume that there is something to which you object in the wording or is there something that you are not understanding or objecting to conceptually. The core of argument number 2 is that animal flesh is a solid and that because of this, animal tissue cannot be modeled as a fluid for the...
I think it's safe to say that the sponsors of argument number 1 actually would accept a cucumber or a jellyfish (particularly the jellyfish) to be modeled after a fluid. And silly or not as the concept might be, an acceptable proof would be helpful one way or another.
Ask yourself instead...
"a fluid is a material continuum that is unable to withstand a static shear stress".
I believe this is what is meant by a fluid environment; something like air or water.
Naty, thank you for the idea, but the quesion isn't whether ballistic gellatin would be a suitable alternative for testing terminal ballistics. We're more concerned with whether the properties of animal tissue are fluid or non-fluid.
There has been a running debate for some time on an archery forum with one rather simple question going unresolved.
Here are the opposing arguments. Can anyone shed light on which is most accurate?
Argument 1. Animal tissue must be modeled after a fluid for the purposes of terminal...
Interesting
There is a general assumption that increase in velocity means increase in resistance, which is true in projectiles moving through fluid (drag equation) but not for projectiles moving through solid or semi-solid objects. Animals such as deer and other vertebrates consist of muscle...
Actually, the assumption is that a GIVEN bow will have X-amount of potential, which will wind up as KE in the arrow being launched. How much KE will depend on the mass and velocity, of course, but it's typically a variation of less than 10% with a bow's efficiency being best at heavier arrow...
Assuming arrows of different mass are launched with equal KE and lose none of it to drag in flight, they would arrive with the same KE. Now comes the consideration of resistance - but the resistance is not drag. Drag only occurs when an object is moving through fluid and our target is not...
In Traditional Archery, there is a widely held belief that momentum is the best indicator of an arrow's capacity for penetration. The most important support for this theory comes from this document: The Ashby Report<---Link to document (PDF)
This document has never been reviewed or proofed...