Thomm Posted April 25, 2000 Share Posted April 25, 2000 Dear Lewis! As the shockwave travels with the speed of sound, how can it be overtaken by shrapnel? Maybe you mean the hot gas, but this is not the shockwave ... Link to comment Share on other sites More sharing options...
Username Posted April 25, 2000 Share Posted April 25, 2000 High explosive is any material that explodes and expands faster than the speed of sound. The speed of sound is not the speed of the expanding gases/flame front (I am calling this a shockwave, perhaps a poor choice of words, you tell me). The expanding gases/flamefront rapidly loses speed and the shrapnel will overtake it (shrapnel speed does depend on its size too). The acoustic energy resulting from the explosion WILL travel with the speed of sound. You are implying this is a 'shockwave' and I cant use that word to describe the expanding gases/flame front. Okay. (And people say I nitpick...) Lewis Link to comment Share on other sites More sharing options...
Thomm Posted April 26, 2000 Share Posted April 26, 2000 Sorry to bother you, Lewis! My post is a result of my ignorance, not meant as nitpicking. For some reason I have a problem with gas travelling at supersonic speeds. I guess I have the wrong equation in mind (conservation of momentum between gas state in front and behind a shockwave). Not really my field, obviously ... Link to comment Share on other sites More sharing options...
Username Posted April 26, 2000 Share Posted April 26, 2000 <BLOCKQUOTE>quote:</font><HR>Originally posted by Thomm: Sorry to bother you, Lewis! For some reason I have a problem with gas travelling at supersonic speeds. I guess I have the wrong equation in mind (conservation of momentum between gas state in front and behind a shockwave...<HR></BLOCKQUOTE> No bother. Think of the "gas" as particles just like the shrapnel. It can be accelerated to a velocity also. Sound is just energy travelling through a medium though. I THINK (dont quote me) that the "sound" starts at the point where the explosion gets subsonic. The rapid expansion of the gas smacks the atmosphere around it causing the sound. Which brings up a stupid point: Is there noise inside an explosion? Is this the "ka" in "kaboom"? Inquiring minds want to know... Lewis Link to comment Share on other sites More sharing options...
Guest Big Time Software Posted April 27, 2000 Share Posted April 27, 2000 Lewis, although the science is WAY over my head, this is my understanding. The sound is generated from the point of exceeding the sound barrier. Well, at least it makes sense to me And as for your question... I think you would have a hard time finding volunteers for that experiment even if a test could possibly pass the Ethics board Steve Link to comment Share on other sites More sharing options...
Colin Posted April 27, 2000 Share Posted April 27, 2000 <BLOCKQUOTE>quote:</font><HR>Originally posted by Username: Drop a 15 pound weight on your toe. <HR></BLOCKQUOTE> Ow. That hurts. ------------------ Visit my webpage! http://cm4mac.tripod.com Link to comment Share on other sites More sharing options...
Fionn Posted April 27, 2000 Share Posted April 27, 2000 Well, if we really look at this mathematically sound can only, ever, reach a speed of 330 m/s in air. Sound speed is affected by things such as moisture in the air, fog, smoke etc which can both refract sound waves and also can cause it to speed up or decrease in speed due to their effect on air density. Anyways... Sound is merely one of the forms of energy released when the potential energy (yeah I know I'm mixing terms here but it is easier for non-mathos to follow this way) of the big block of explosives is transformed, by detonation into various other forms of energy ( heat, light, sound etc). The sound waves can be assumed to be virtually immune to interaction with other energy forms emanating from the epicentre of the explosion ( there is a momentary density effect due to displacement of air etc but that doesn't create a total vacuum and really is so fleeting it needn't bother us given the crude means at our disposal in this discussion. ) Anyways, the point is that after accelerating to 330 m/s the sound wave exists (we'd all agree on this). While accelerating to 330 m/s the sound wave also must exist (although with different properties). Lastly, since we have shown that the existence of a sound wave isn't dependent upon the existence or non-existence of the compression front, heat or light it follows that the sound wave can exist at all times following the detonation although it doesn't achieve fully characteristic behaviour until the shockwave dissapates and the sound wave can travel through relatively unroiled air. Basically my contention is that the shockwave is independent of the sound wave and that the sound's existence is independent of such a shock wave and thus the sound exists before the shockwave goes subsonic. Taht's my take anyways. I normally don't concern myelf with this sort of stuff. I'm much more interested in the effects of the thing going kaboom on the armour or men near it usually . Link to comment Share on other sites More sharing options...
Trooper Posted April 27, 2000 Share Posted April 27, 2000 OK.. If we're going to go on round nomenclature (and I would find 'round' to be quite acceptable), then what the devil would you categorise the British system of separate warheads and bagged propellant charges? NTM Link to comment Share on other sites More sharing options...
Trooper Posted April 27, 2000 Share Posted April 27, 2000 OK.. If we're going to go on round nomenclature (and I would find 'round' to be quite acceptable), then what the devil would you categorise the British system of separate warheads and bagged propellant charges? NTM Link to comment Share on other sites More sharing options...
nijis Posted April 27, 2000 Share Posted April 27, 2000 Um, if anyone wants to get back to the original Panther/Tiger thing, a previous thread, if I recall, concluded that the Tiger is up on the Panther in terms of 1) flank armor and 2) HE shell effectiveness. The Panther wins in terms of 1) front armor 2) penetration 3) mobility 4) turret rotation speed. It's also my understanding that the Germans still continued to think of the Tiger as qualitatively superior to all other tanks, at least through the Normandy battles, and organized them into independent fire-brigade style battalions. Hence, Wittmann (sp?) commanded a Tiger, not a Panther. Does anyone know why this is the case? Is it mechanical reliability? Crew comfort? Hitler had a grudge against the Panther after the early models let him down at Kursk? Elite crews had a year's additional experience with the Tiger, and therefore were more effective in it, making the Tiger the armored equivalent of the QWERTY keyboard? Or does flank armor and anti-infantry stuff make all the difference? [This message has been edited by nijis (edited 04-27-2000).] [This message has been edited by nijis (edited 04-27-2000).] Link to comment Share on other sites More sharing options...
rwcanuck Posted April 27, 2000 Share Posted April 27, 2000 Late in the war the Panther was the obvious choice as the main battle tank for the Germans. The Panther Ausf. F with a 7.5 cm gun & schmalturm turret was already on the production lines when the war ended. The Panther II was close behind in development with a 8.8 cm Kw.K 43 gun and a schmalturm turret. In fact all available Panthers were to be converted with the 8.8 cm Panther-Schmalturm. Link to comment Share on other sites More sharing options...
Ben Galanti Posted April 27, 2000 Share Posted April 27, 2000 I'm not sure what the correct accustic terminology is here, which may be part of the confusion... My understanding though is that there would be a couple of different sounds from an explosion. First, the sound of the explosion it self. By that I mean, the particles of gas (and shrapnel) being accelerated by the rapid release of energy. As those particles move through the air, the deplace the air. This displaced air would be one sound wave. These waves, by their definition, travel at exactly the speed of sound. From fluid mechanics, for air, the speed of sound is solely dependent on temperature. Secondly, for high explosives, once the expanding gas exceeds the speed of sound, it will form a shockwave (I think that's the correct term...) This shockwave is the result of the sound waves from above 'bunching up' on each other. When this overpressure passes an observer, they hear it as a sonic boom. The original sound waves will also be trailing that overpressure wave, and would be heard as a second sound. This second sound can only be heard in a specific area (a cone, whose tip is at the supersonic particle) So, that being said, I would think there would be sound in an explosion. I'm not about to go check it out though... And I thought fluid mechanics would never be useful... Link to comment Share on other sites More sharing options...
Fionn Posted April 27, 2000 Share Posted April 27, 2000 They're called "Separate charge projectiles" or the simpler "separate ammunition". The projectile portion is termed projectile and the powder container is termed either "bag" or "charge" Link to comment Share on other sites More sharing options...
Bastables Posted April 28, 2000 Share Posted April 28, 2000 The Panther II was an earlier design based upon the fear that the Panther ausf D1 and D2 armour would be found wanting in the presumed conditions of 1943’s Russia (those dammed AT rifles were really irritating). The development and successful tests of Schuerzen spaced armour killed the Panther II project as a production vehicle by the 4th of May 1943. But laudable design features were included in the ausf G chassis i.e. the deletion of the wedge on the upper side hull and deletion of the driver’s forward vision block in favour of one rotating episcope. The KwK 43 L71 8.8cm were to replace all KwK 42 L70 7.5cm armed ausf F’s, this included the declaration that all earlier KwK 42 armed ausf F were to be rebuilt once the new gun could be mounted in the Panther Schmalturm. Link to comment Share on other sites More sharing options...
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