Ok, this is my first post on our newly set up Blog and it originates from a topic discussion on one of the kite forums online. The topic was about line drag and the noise some lines make....specifically Q-Powerline. This Blog post helps explain whats actually happening to your lines and why they sing when you fly. The topic was saying that Q-Powerlines have more resistance because they vibrate so loudly. This post was to help clarify that common misbelief amoung kite flyers.
Q-Power line sings quite loudly compared to other lines.
The line itself doesn't cause that much drag. The sine wave caused by the vibration as air rushes around and over the lines is what causes the most drag. Your lines aren't just restricting wind from the diameter of the line but more from the entire sine wave the line is creating. The more the line vibrates, the larger the sine wave - thus the more restriction (and disruption of air flow) the lines will create. This is the same reason that a single strand of wire will cause more wind resistance than a 6" diameter pipe. The air flows smoothly over the pipe (kind of the same way it flows over your kite) but gets very disrupted and distorted from the vibrations caused by the wire. Most of the time your lines will be causing more parasitic drag through the air than your entire kite does because of the distortion of air from the lines compared to the smooth flow of air over the kite or wing.
All lines vibrate. Can't help it, they are thin, long and flexible. As air hits the lines they WILL vibrate!
The frequency that your lines vibrate will determine just how much resistance the lines will give. Lower frequencies produce a very large sine wave and are much larger and more disruptive than higher frequencies that produce a very tiny sine wave. Even though you can't hear any audible vibrations from your lines - they are still vibrating. If you can't hear your lines singing to you, then the vibration is in the sub-sonic frequency range and causes tremendous line drag and resistance. As the power of the kite increases, the frequency that the lines are vibrating at also increases causing your lines to start singing more audibly when they are stretched very tightly.
Q-Powerlines are designed to load up the braid of the lines faster which means that your Q-Powerlines will start singing at a very high pitch very quickly in lower winds (as compared to other flying lines). This high pitch vibration is a much higher frequency than what is obtainable by other lines and allows Q-Powerline to have much less resistance and parasitic drag than any other line on the market. Q-Powerline is the only known company that has actually wind tunnel tested their lines against hundreds of other lines and proven that their lines have less parasitic drag (military contract requirements).
Q-Powerline can be a bit loud at times and will sing much louder and start to sing quicker than other line. Some people take this as adding more drag or reaching the breaking strain of the line faster but that is very far from the truth. It actually gives much much less drag as explained above but, because the line is vibrating at a much higher frequency, it actually helps maintain the rated breaking strain of the lines more than a line that is vibrating at a much lower frequency (think of a line that is constantly being pounded on by huge whipping yanks compared to a line that is only being tugged on in very small inputs).
So, Q-power is more audible than other lines but has less parasitic drag overall and higher strength when under load.
Sorry to drag on about this.... (pun intended) Just some useless information for everyone to share next time your sitting around with your buddies waiting for the wind to blow. I need to get out of this office and fly!!!!!!
So, there goes my first Blog post. Hopefully more will be coming soon. Let me know if you have any questions or comments and maybe we can even open up a new topic about them.