b3ta.com links
You are not logged in. Login or Signup
Home » links » Link 1316787 | Random

This is a link post I love Forumla 1 but I hate the sounds the current cars make
Maybe we should get this guy to dub each race.
(, Fri 26 Jun 2015, 17:18, , Reply)
This is a normal post not unlike the intro to meatloafs bat out of hell
Done on guitar dontchknow
(, Fri 26 Jun 2015, 17:27, , Reply)
This is a normal post Thank goodness for the last few seconds
Until he looked up, I wondered what he might have had in place of eyes hidden under that hat.
(, Fri 26 Jun 2015, 17:43, , Reply)
This is a normal post You're still here? I smell a rat.
*narrows eyes*
(, Fri 26 Jun 2015, 22:21, , Reply)
This is a normal post Pete Doherty off the skag?

(, Fri 26 Jun 2015, 18:06, , Reply)
This is a normal post Pe-Do

(, Fri 26 Jun 2015, 22:09, , Reply)
This is a normal post Question about the sound of F1 cars:
Presumably some of the smaller parts of a high revving F1 engine are moving at greater than the speed of sound, so is part of what we hear thousands of tiny sonic booms every second?

(I've tried Guardian Notes & Queries and an engineer mate who works for Jaguar, help me B3ta, you're my only hope...)
(, Fri 26 Jun 2015, 18:27, , Reply)
This is a normal post
Every car has a little failed SRV inside
(, Fri 26 Jun 2015, 18:39, , Reply)
This is a normal post if you can find the bore x stroke them mutiply that by the peak revs available you will get the vmax of the piston crown
which would occour at just before bottom dead center.
The crown of the piston will travel further then the crank for the same amount of rotary motion and there for will have to travel faster to keep pace.

Think of an ice rink with a line of 21 people linkinh arms and starting to spin around the central person, the outside will be seen to be traveling at a much fast rate than the central figure.
however Williams had there mechanical kers device with counter rotating weights spinning in the region of 100,000 rpm
And dont forget the turbo will be spinning even faster to get the best performance, so take your pick on what part you would like to hear the small sonic booms from.
also i have just had a truly scrummy COD FISH FINGER buttie, so good it needed emphasis .

my work here is done
(, Fri 26 Jun 2015, 19:30, , Reply)
This is a normal post Blimey just reread that and it seems to make sense WTF have i been taking for that to appear out of the blue?

(, Fri 26 Jun 2015, 19:54, , Reply)
This is a normal post OK, that's an interesting problem, let's see what I can come up with.
Firstly, the speed of sound you refer to is the speed of sound in free air. It simply measures the speed at which pressure waves are transmitted through an elastic medium, and is primarily dependent on the density of that medium. The density of a gas is governed by its temperature and pressure so let's just take the sea level value of ~340m/s for now and see where we end up. The speed of sound in the engine block will be in the region of 6000m/s so let's neglect that.

The pistons are the primary moving part to consider - they have the largest range of movement and therefore will displace the largest quantitiy of gas (indeed, that's what they're designed to do).

OK, so let's pick an engine to try. The Renault RS27 (PDF doc) powered Red Bull to the championship in 2013, the last season for the V8s. This revved over 18000 RPM. Unfortunately, what I can't find out is the piston stroke, so lets assume it's close to that of the V6 replacement's 53mm and call it 50mm (0.05m) for ease.

So:
- 18000 RPM gives 300 revs/sec.
- That gives a distance to cover of 300*0.05 = 15m

Therefore *on average* the piston is travelling at 15 m/s. Now at both ends of the stroke it's stationary or covering little distance, but even if we double the speed to 30m/s it's still travelling under 10% of the speed of sound in air.

------ tl;dr ------

Q: Is part of what we hear thousands of tiny sonic booms every second?
A: No.
(, Fri 26 Jun 2015, 20:14, , Reply)
This is a normal post I prefer the Milliband answer
"Hell Yes"!
(, Fri 26 Jun 2015, 22:29, , Reply)
This is a normal post THANK YOU FOR YOUR BRAIN

(, Sat 27 Jun 2015, 1:01, , Reply)
This is a normal post Rereading it this morning
I realise that, apart from it being a not entirely coherent explanation in desperate need of editing, I also cocked up the calculation:

The distance travelled by the piston during one cycle is double the stroke length. i.e. up and down the cylinder. That still doesn't get you anywhere near sonic velocities though, so doesn't change the conclusion.
(, Sat 27 Jun 2015, 9:16, , Reply)
This is a normal post You are Mona Lisa Vito AICMFP
www.youtube.com/watch?v=6qgREMBTE28
(, Sat 27 Jun 2015, 7:25, , Reply)
This is a normal post *Pays fiver*
*Strips naked and stands in front of mirror*

I want my money back!
(, Sat 27 Jun 2015, 9:20, , Reply)