You’ve all heard them, those Fomula 1 commentators talking about getting into the “Slipstream” of the car in front. Well I’m sorry to say that unless the car in front is propeller driven, there is no “slipstream”. “Slipstream” is the air thrust bck by a propeller which is being driven, nothing else.
I’ll try and explain. (Look at my drawings below). You’ve all seen a bolt – the threads have a “pitch”, when you screw the bolt in, it moves a fixed distance determined by the “pitch”, on a screw this is called the “Lead”. It moves the full distance because it is being screwed into something solid.
A propeller (ships and Aircraft) also has pitch, but it is screwing into a fluid (water/air) so instead of travelling the full distance it should, the “theoretical distance” it Slips and travels less. The difference between how far it should travel and how far it does travel is called “Slip”. The air thrust backwards due to this slip is the Slipstream”. NO PROP = NO Slip = NO Slipstream !!!
What the racing boys actually mean is “Wake Turbulence” and thats something entirely different!
KeithMac
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By: ageorge - 3rd October 2002 at 18:21
RE: Slipstream!!
[updated:LAST EDITED ON 03-10-02 AT 06:22Â PM (GMT)] A few years back I flew through the wake turbulence from a Tornado , i was taking microlight lessons , sitting in the front and too busy watching the ground – the backseater grabbed the bar and smashed it off my helmet frantically pointing in front of me , eventually I spotted a Tornado crossing in front of me at the same height as me travelling North-South as I was heading West about 1k out , the Tornado was out of sight but when we hit its turbulence it was quite violent , we did phone Leuchars to ask if they knew of a Tornado which had not read the area NOTAM’s and did get a reply apologising as it was an Italian exchange pilot exiting the area. 2 weeks later , same place , I spotted a Hercules travelling North and then noticed a Tornado behind it waggling its wings while overtaking , luckily we were on finals and did’nt fly through the wash , interesting though !!
By: keithmac - 2nd October 2002 at 20:32
RE: Slipstream!!
Hi Lancman, I do try to get out, but with no flying Vulcan and only one flying Lanc, it is really worth it?
KeithMac
By: Bluebird Mike - 2nd October 2002 at 10:13
RE: Slipstream!!
…I WAS only kidding, by the way!
By: futurshox - 2nd October 2002 at 07:28
RE: Slipstream!!
Mind you, a propellor-driven F1 car might liven things up a bit…!
By: Ant.H - 1st October 2002 at 23:02
RE: Slipstream!!
Thanks again Kieth,another enlightening post :). I have to say I disagree with Lancman!
Keep em coming mate!
By: Moggy C - 1st October 2002 at 21:34
RE: Slipstream!!
Damn,
It’s sort of depressing when you find that something you’ve believed for around fifty years isn’t actually so.
Moggy
By: Bluebird Mike - 1st October 2002 at 20:03
RE: Slipstream!!
You really want to get out more, do you know that?! 😉
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October 1, 2002 at 7:56 pm