y0da900
06-15-2006, 01:34 PM
Like the title says, many of us understand that having turbulent flow around an object can greatly reduce it's drag and increase it's accuracy (in the case of a true projectile with an unpowered trajectory). While what seems to be the most obvious answer to this has been shot down (dimples, like the ever compared to golf ball), there should be many other ways to induce a turbulent field around the paintball, such as mentioned by Tom Kaye before in a post about where he thought some improvements in technology could be made.
Very high speed two shot bursts where the 2nd ball would draft close behind the first ball for greater accuracy. The first ball would disrupt the air column and leave behind a turbulent wake. The turbulence would disrupt the laminar flow that leads to vortex shedding on the 2nd ball. Disrupt the vortex and improve the accuracy.
While that is always a possibility, I would love to see some other ideas that might possibly induce turbulence and increase the accuracy of paintballs.
And one big question before I launch into an idea I've been mulling over for a while: I know that as an objects speed increases, the flow around it has a tendency when it reaches a terminal speed dependent on boundary and fluid conditions, to make the transition from laminar flow to turbulent flow. In the case of a projectile moving at a given speed in a turbulent flow, as the turbulence should greatly reduce it's drag, the rate at which the projectile decelerates also reduces, allowing it to fly faster longer. While it can maintain a set speed for a longer period of time, how delayed will the transition back to laminar flow around the projectile be as it begins to slow down? Is the transition in this direction linearly proportionate to the transition from laminar to turbulent, or does the flow have a tendancy to remain turbulent once there?
Now with a huge assumption made regarding that long winded question: As a pojectile moving through a turbulent field has a reduced drag, therefore reduced deceleration, the turbulence surrounding the projectile will be less likely to reduce back to laminar flow while the projectile is moving, even if it enters a pocket of otherwise laminar flow (turbulence inducing turbulence so to speak).
And finally, for the idea. As Tom (again) has shown, in most situations, the most important, and potentially only, important part of the barrel as far as getting the ball up to speed is the first 8" - 10"., and the rest is balance and user preference. If a barrel has a control bore of these 8-10", and then, say, another 4-8" of oversized bore (not excessively, but more so than the fronts on most 2-piece barrels), and air was injected at the end of the control bore through a (series of) nozzle(s), allowing the air injected to reach relatively high velocity. If this injected air was timed in a very short well controlled burst, and directed down the barrel (as to prevent simply making a larger pressure gradient), then instead of simply pushing against mostly stagnant (laminar) air at atmospheric pressure, then immediately after leaving the control portion, the ball enters a pocket of turbulent air which should reduce the drag on the ball, and therefore increasing it's useful range and accuracy. This is, again, all assuming that turbulent air desires to remain turbulent more so than laminar desires to remain laminar.
In the event that this assumption is completely wrong, can anyone think of ways, other than having the ball follow an initial projectile's wake, to help maintain this turbulent pocket around the ball to do things many companies claim, but none can do.
Pipe in, let's hear those off the wall ideas, it's thinking outside the box that will make innovations in this sport instead of a line of guns with the next generations simply fixing flaws in the previous.
Very high speed two shot bursts where the 2nd ball would draft close behind the first ball for greater accuracy. The first ball would disrupt the air column and leave behind a turbulent wake. The turbulence would disrupt the laminar flow that leads to vortex shedding on the 2nd ball. Disrupt the vortex and improve the accuracy.
While that is always a possibility, I would love to see some other ideas that might possibly induce turbulence and increase the accuracy of paintballs.
And one big question before I launch into an idea I've been mulling over for a while: I know that as an objects speed increases, the flow around it has a tendency when it reaches a terminal speed dependent on boundary and fluid conditions, to make the transition from laminar flow to turbulent flow. In the case of a projectile moving at a given speed in a turbulent flow, as the turbulence should greatly reduce it's drag, the rate at which the projectile decelerates also reduces, allowing it to fly faster longer. While it can maintain a set speed for a longer period of time, how delayed will the transition back to laminar flow around the projectile be as it begins to slow down? Is the transition in this direction linearly proportionate to the transition from laminar to turbulent, or does the flow have a tendancy to remain turbulent once there?
Now with a huge assumption made regarding that long winded question: As a pojectile moving through a turbulent field has a reduced drag, therefore reduced deceleration, the turbulence surrounding the projectile will be less likely to reduce back to laminar flow while the projectile is moving, even if it enters a pocket of otherwise laminar flow (turbulence inducing turbulence so to speak).
And finally, for the idea. As Tom (again) has shown, in most situations, the most important, and potentially only, important part of the barrel as far as getting the ball up to speed is the first 8" - 10"., and the rest is balance and user preference. If a barrel has a control bore of these 8-10", and then, say, another 4-8" of oversized bore (not excessively, but more so than the fronts on most 2-piece barrels), and air was injected at the end of the control bore through a (series of) nozzle(s), allowing the air injected to reach relatively high velocity. If this injected air was timed in a very short well controlled burst, and directed down the barrel (as to prevent simply making a larger pressure gradient), then instead of simply pushing against mostly stagnant (laminar) air at atmospheric pressure, then immediately after leaving the control portion, the ball enters a pocket of turbulent air which should reduce the drag on the ball, and therefore increasing it's useful range and accuracy. This is, again, all assuming that turbulent air desires to remain turbulent more so than laminar desires to remain laminar.
In the event that this assumption is completely wrong, can anyone think of ways, other than having the ball follow an initial projectile's wake, to help maintain this turbulent pocket around the ball to do things many companies claim, but none can do.
Pipe in, let's hear those off the wall ideas, it's thinking outside the box that will make innovations in this sport instead of a line of guns with the next generations simply fixing flaws in the previous.