What is the KSP Sound Barrier Speed? (at various altitudes)

[inigma]

I am looking to create a Break the sound barrier! contract recreating most of the conditions/parameters that the Bell X-1 faced when attempting the same. I need an equivalent altitude and speed in KSP. Anyone know where I can find the answer, or do they have one to provide? I will credit you in the Contract Pack if you give me a near exact altitude  and speed to use for the contract.  See link in my sig for GAP.  Kudos if you can also give me speeds at the same altitude or better for other significant firsts in historiy: Mach 2, and Mach 5.

Thanks!

Edited December 30, 2015 by inigma

[Reactordrone]

The highest speed of sound value you should encounter on Kerbin will be 340m/s. It reduces a little at higher altitudes and then increases again but if you aim for 340 you should be ok for a "break the sound barrier" contract.

 

ETA- the X-1 itself got to just under 361m/s on its first supersonic flight at 13,100m.

Edited December 30, 2015 by Reactordrone

[NathanKell]

Nope, you're forgetting that KSC is on the equator so the air temperature is rather higher than the reference temperature. Actual speed of sound during the day near KSC at sea level is ~352m/s. It decreases to about 300m/s at 8km and holds there, more or less.

[Reactordrone]

You may find this thread useful,

http://forum.kerbalspaceprogram.com/index.php?/topic/114789-speed-of-sound-in-10/

[inigma]

If the speed of sound is on average 340 m/s then technically speaking Mach 2 would be 680 m/s?

[NathanKell]

How are you computing "average"?

As was discussed above, it varies with temperature (and temperature varies with altitude and latitude and day/night). 343m/s is the speed of sound at 15 C (288 K or 59 F), which is the reference temperature at sea level for the standard atmosphere, but is most certainly not the temperature at KSC during either day or night. In the mid atmosphere, the speed of sound is around 300m/s, and if you wanted to pick a 'round number' use that, it's going to be valid much more often than the sea level number is, for general use.

[inigma]

1 minute ago, NathanKell said:

How are you computing "average"?

As was discussed above, it varies with temperature (and temperature varies with altitude and latitude and day/night). 343m/s is the speed of sound at 15 C (288 K or 59 F), which is the reference temperature at sea level for the standard atmosphere, but is most certainly not the temperature at KSC during either day or night. In the mid atmosphere, the speed of sound is around 300m/s, and if you wanted to pick a 'round number' use that, it's going to be valid much more often than the sea level number is, for general use.

I'll use 343 m/s then. What about mach 2? just * 2?

[NathanKell]

Yes.

(343m/s will be valid at precisely 2km over KSC during the day.)

[kcs123]

Maybe it will be good idea what kind of formula DaMichel used to display Kerbal Flight Data near navbal. I think it works properly with stock and with FAR physics.

[Claw]

8 hours ago, inigma said:

What about mach 2? just * 2?

Yep

[Stephen Locksley]

On 12/31/2015 at 5:59 AM, inigma said:

I am looking to create a Break the sound barrier! contract recreating most of the conditions/parameters that the Bell X-1 faced when attempting the same. I need an equivalent altitude and speed in KSP. Anyone know where I can find the answer, or do they have one to provide? I will credit you in the Contract Pack if you give me a near exact altitude  and speed to use for the contract.  See link in my sig for GAP.  Kudos if you can also give me speeds at the same altitude or better for other significant firsts in historiy: Mach 2, and Mach 5.

Thanks!

I tested the Jebla KKC, it was faster than sound. Breaking the sound barrier is possible, as you would go ridiculously fast.