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Parachute/Streamer Question

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Mike

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I've heard lots of times that using a streamer reduces drift and was wondering just how true this is. Is the drift reduced because the descent rate is quicker? Or does the wind 'catch' the parachute more and move it further, does the cross wind slip round the streamer more?

Any help would be great, thanks.
 

Darian Rachal

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Mike, My "guess" would be that if the streamer would slow the descent to the same rate a the parachute, the drift would be the same.
 

mkmilion

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A streamer drifts less. It's because it isn't effected by cross wind. It still has the same decent as a parachute just less drift. I believe 18'/sec. is optimal. I hope this helps.
 

KermieD

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Streamers as a rule descend much quicker than chutes. As you surmised at the start, the reduction in drift is at least in part due to an increased descent rate.
 

NUBlackshirts

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Also, streamers won't suffer as much from the effects of thermals.
 

jflis

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Another odd problem that you can encounter is a parachute actually producing *lift*.

From a thread on Streamers ( https://www.rocketryforum.com/showthread.php?s=&threadid=1964 ), I commented:


Two, you could cut a SPILL HOLE. Cut out the logo in the center of the chute (some day our chutes will put the logo elsewhere so you don't have to cut IT out... LOL). This will allow air to *spill* out of the canopy. This does two things. One, it reduces the effect of thermals lifting the chute. Two, it prevents wind from colapsing the leading edge of the chute (picture a cross section of a parachute). This collapsing forms the cross section of a chute into an airfoil and will produce lift in the wind stream. The spill hole prevents this.
jim
 

arthur dent

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Is there a rule of thumb for the size of a spill hole with regards to the size of the parachute??
 

jflis

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well, the rule of thumb I've always applied is to cut out the entire logo area.
 
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