Miks15
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| posted on 18/11/09 at 06:06 PM |
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Speed of a badminton shuttlecock
Hi fountain of knowledge!
As one of my uni courseworks, as a group we have to estimate the maximum velocity of a shuttlecock after a professional player smashes it. Bearing in
mind the advances in racquet technology.
Can anyone reccomend a starting point for this problem? Mabye some formulas etc.
Thanks all
Mikkel
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Steve G
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| posted on 18/11/09 at 06:11 PM |
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A mate of mine who i went to school with (former member off here Paulstiger6) used to play for Wales and he was timed at about 180mph on a decent
smash.
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Tatey
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| posted on 18/11/09 at 06:11 PM |
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This might be wrong but its how i'd go about it:
Found out how much force a player hits the shuttle cock with
Find out the mass of the shuttle cock
The drag caused by air resistance
The time the shuttle cock is in contact with the racket
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bilbo
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| posted on 18/11/09 at 06:13 PM |
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Surely, the maximum velocity is achieved at the point it's hit by the racquet? In which case, this should pretty much match the speed of the
racquet, regardless of the aerodynamics of the 'cock? So really, you need to work out how fast someone can move/swat the head of the racquet?
Not sure if that make it easier or not?
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paul the 6th
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| posted on 18/11/09 at 06:18 PM |
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get someone to smash a shuttlecock through a speed camera and wait for the NIP? 
GoDesign.me.uk - Self Adhesive Vinyl Artwork, Wide Format Printed Artwork and Customised Heat
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Steve G
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| posted on 18/11/09 at 06:26 PM |
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quote:
Originally posted by bilbo
Surely, the maximum velocity is achieved at the point it's hit by the racquet? In which case, this should pretty much match the speed of the
racquet, regardless of the aerodynamics of the 'cock? So really, you need to work out how fast someone can move/swat the head of the racquet?
Not sure if that make it easier or not?
Dont forget you have the effect of the strings - that'll be complex to work out on its own surely!!
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liam.mccaffrey
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| posted on 18/11/09 at 06:30 PM |
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Estimate how? From 1st principles, from video evidence?
consider air resistance, terminal velocity, conservation of momentum.
Sounds interesting though
[Edited on 18/11/09 by liam.mccaffrey]
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scootz
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| posted on 18/11/09 at 06:32 PM |
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67.4mph if I'm not mistaken...
It's Evolution Baby!
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scootz
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| posted on 18/11/09 at 06:32 PM |
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... which I am!
It's Evolution Baby!
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Dangle_kt
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| posted on 18/11/09 at 06:38 PM |
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Shuttlecocks will be very interesting, as it is beig hit it at it's least aerodynamic, it turns in the air as soon as it leaves the racket... So
is it quickest as t leaves or as it starts facing the right way?
If it was me I'd start with a slow mo camera and a large peice of checkered board, suspended approx where the smash will take place. View the
footage and then work backwards, as otherwise you are bound to miss something.
Intersting though, but I'm not sure getting help from a load of geeks is really cricket!
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rgrs
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| posted on 18/11/09 at 06:39 PM |
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Try googling simon archer, he is still the current world record holder set at 162 mph, although there have been claims of faster speeds none of these
have been fully verified.
Also just to add more issues , shuttles are made in varying 'speeds' these are needed to try and compensate for different temperatures
and moisture levels.
hth Roger
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speedyxjs
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| posted on 18/11/09 at 06:50 PM |
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Its all about angular and tangential velocity. You would need to know the average length of a players arm, the length of a badminton racket and the
average torque given by the players arm. Once you have these figures, its quite easy 
How long can i resist the temptation to drop a V8 in?
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Steve G
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| posted on 18/11/09 at 06:58 PM |
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"Men's doubles player Fu Haifeng of China set the official world smash record of 332 km/h(207 mph) in the 2005 Sudirman Cup. The fastest
smash recorded in the singles competition is 305 km/h (190 mph) by Taufik Hidayat of Indonesia."
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lsdweb
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| posted on 18/11/09 at 07:34 PM |
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I've gone back to competitive badminton at the ripe old age of 45 and in my case the answer is "not fast enough!" :-)
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02GF74
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| posted on 18/11/09 at 08:15 PM |
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quote:
Originally posted by bilbo
Surely, the maximum velocity is achieved at the point it's hit by the racquet? In which case, this should pretty much match the speed of the
racquet, regardless of the aerodynamics of the 'cock?
definitely not - you forget the "whipping action" of the shaft plus the tension in the strings.
since we are dealing with a rather complex shape, say compared to a ball, I doubt you'll get a smple formula for the speed - plus the bit of
flipping round.
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Ivan
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| posted on 18/11/09 at 08:19 PM |
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Assuming that you have to calculate the speed and not just measure it the factors below will have to be considered:
The highest speed will be as it leaves the face of the racquet and before it turns around to begin it's flight to the other side, the factors at
play are speed of the shuttle before it's hit, the mass of the shuttle, the compressibility of it, the give and elasticity of the strings, the
speed of the racquet and the inertia and springiness of the racquet, I would consider the racquet from the wrist up as the wrist is a flexible joint
of unknown stiffness so would be almost impossible to assess.
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D Beddows
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| posted on 18/11/09 at 08:21 PM |
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'estimate' may be the key word if it actually appears in the question - just though I'd mention it before you go off and spend 3
weeks actually trying to work it out rather than a few hours actually answering the question you may have been given 
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Miks15
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| posted on 18/11/09 at 08:26 PM |
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thanks for all the words guys.
Yes it is an estimation. So one thing i think we can do is assume the shuttlecock as a sphere, as the point i will be looking at will be the instant
it leaves the racquet.
So a couple points to look at will be...
Speed of the racquet during a smash.
Mass of both racquet and shuttlecock.
Elasticity of both racquets strings.
Anything else?
Thanks
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D Beddows
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| posted on 18/11/09 at 08:53 PM |
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yes, I'd seriously consider thinking outside the box a bit more why use badminton with it's strange shaped shuttlecock as the
example.......? if they wanted you to calculate the velocity of a sphere leaving a racquet why not tennis?
There are too many variables in the question you've given us which are absolutely impossible to calculate for a piece of university coursework
so have you considered the possibility that the question isn't quite as literal as you are taking it to be?
- which professional is hitting the shuttlecock? man or woman? what type of racket are they using? what string tension do they prefer? which type of
shuttlecock are they hitting? there are just too many unknowns even for an estimation unless you have been given other data !
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02GF74
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| posted on 18/11/09 at 09:31 PM |
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..... and after all of this, you know what the answer is: somewhere from 60 mph for an average player to 150 mph for a professional.
just write that and spend some time in the pub or building the kit.
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Dingz
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| posted on 18/11/09 at 09:58 PM |
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Its a great question! Ive played for over 40 years and would love to see a slo-mo film of a good smash, I expect the shuttle will compress a huge
amount at the moment of impact then it has to extend at the same time the strings are trying to recover. + the forward motion of the raquet. Too many
sums for me
Phoned the local ramblers club today, but the bloke who answered just
went on and on.
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hillbillyracer
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| posted on 18/11/09 at 10:41 PM |
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quote:
Originally posted by Miks15
Yes it is an estimation. So one thing i think we can do is assume the shuttlecock as a sphere, as the point i will be looking at will be the instant
it leaves the racquet.
To my mind I think you're right there, the maximum speed will be as it leaves the racquet as anything after that will have to be slower as there
is no more energy going in after that point. This means it's shape regarding air resistance is of no matter, although it will deform &
spring back in a different manner to a ball.
Mabye the question asks about a shuttlecock rather than a ball just to throw you off track?
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craig1410
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| posted on 18/11/09 at 11:16 PM |
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Hi,
I would modify a shuttlecock by removing the feathers and replacing them with material of equal mass but which will not increase air resistance. Then
I would then attach a ticker tape speed measurement device to the shuttle head and try a few test hits. The tape will be torn most of the time
probably but you should get the occasional successful test and can measure the speed from the ticker tape intervals.
By removing the feathers you should be able to get more consistent results and since you are interested in max speed then you don't really care
about air resistance effects.
Another option would be to strike the shuttle head from a point, say, 10 metres from a metal plate. The use a microphone to record the sound of
hitting the shuttle head and it hitting the metal plate. You should be able to analyse the sound recording to establish the flight time and therefore
measure the average speed during flight. Try this at different distances (eg. 5m, 15m) to help extrapolate the speed as it leaves the racquet. Do lots
of samples to eliminate error margins as much as possible.
You could even establish drag co-efficient by dropping from a height to achieve terminal velocity and timing the last, say, 10 metres of the drop to
work out the velocity. You can work out Cd from this velocity and then use this Cd in your previous experiment to work out initial speed from average
speed.
I hope these ideas help.
Craig.
ps. I was county badminton champion as a junior.
[Edited on 18/11/2009 by craig1410]
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hughpinder
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| posted on 19/11/09 at 08:35 AM |
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Its an engineering estimate, right.
Option 1.
length of a court = 26.8m
watch/guess time you have to react to a smash with both players at the back of the court, say 0.4sec (watch some playing on the internet - slow it
down if you can)
This gives average speed of approx 150mph. See if you can do the same for the time the shuttle takes to cover the first half of the court - this will
give an indication of how much faster the initial speed was.
The highest speed will be higher than that! The speed of a shuttlecock drops off very quickly - my guess is once the feathers flare out. Therfore
guess the maximum will be ca 200mph.
Option 2.
Obtain dvd of pro playing.
Find a smash. Get to the first video frame after the shuttlecock leaves the raquet, freeze frame forwards one frame and estimate distance. Find out
frame rate of recording (25fps?) and calculate from that.
Both thes options only need a couple of things to be actually estimated.
Option 3 - probably only applicable if this is a project designed to take the whole year!If you want to calculate 'properly' you will need
to find data for
Speed of raquet head (or work out from muscle contraction rate/length of racquet, amount of flexibility in the frame/head/...........)
flexibility of the strings and head in combination (I guess agood margin for error here as it will vary a lot, even with the different weights of
shuttlecocks(tournament feather ones are enormously heavier than plastic), energy/momentum transfer efficiency.......
I guess in the end you would end up having to video a pro smashing different weight objects to even get decent data on the shaft flexibility etc,
unless you can estimate that from the type of carbon fible, resin used, methiod of laying up, exact shape/structure of all elements of the
racquet....
For all estimates don't forget to include an estimate of how accurate each of your data sources is - E.g. For option 1 from a video on slow
advance you can probably get an average speed with your inputs accurate to +- .05 sec, +-1m.
For the last 'full calculation' option, even estimating how accurately you can estimate the speed will be a problem!
My guess is that part of the assignment is to make you determine how far to go in doing the calculation!
I hope this helps
Regards
Hugh
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