How fast can a plane go in atmosphere? What is the limit?

[n0xiety]

I was able to build a stable jet that can go 1500m/s to 1550m/s at 25k to 30k and stay at that speed with long range ability. So im curious can i do better? Any suggestions if you have built a plane that can go faster than this and still be stable?

Requirements;

1.Plane should be able to reach a certain altitude and keep that altitude within 2k margin without speed loss.

2.Plane shouldn't overheat enough to destroy parts while going max speed at the optimal altitude.

3.Plane should have enough fuel to do a Kerbin circumnavigation.

4.Plane should be able to reach the desired altitude and speed under its own power. So no rocket boosters or vertical takeoffs.

Hoping to improve my design with your suggestions. Ty in advance.

[Prepper-Jack]

Well, I would imagine 1500-1550 is pretty much the most reasonable sustainable max speed range one can expect in atmospheric flight - and that only at the very high altitudes. I've build small RAPIER test jests that go 1600+ in a slightly lower environment, but they eventually melt. Turbos, of course, are worse. I've gotten one to around 1500 before, slightly sub 20k, but it doesn't last long at that speed at that altitude (again, heat).

Most of my tests were very small and light probes stripped down to minimal fuel for absurd TWR. After some testing, I found that making the plane larger (adding more engines) would increase theoretical top speed - but it would just incinerate the plane even sooner. Precoolers everywhere helps - but it doesn't stop the eventual overheat.

For maneuverability, I've found that basic elevons used as elevators, tail fins, and canards are enough to handle super high speed flight.

Edited June 4, 2015 by Prepper-Jack
Typo

[ajburges]

Whiplash and RAPIER will never exceed sustained level speeds of 1.8 and 2 km/s respectively. That is when they lose all thrust due to velocity.

In practice you won't see much over 1 and 1.3 km/s where thrust starts decreasing. You need to over engineer badly to beat those speeds.

Best test bed would be RAPIER, Mk1 tank, probe core, and shock cone intake. Minimal (if any) wings.

[n0xiety]

Whiplash and RAPIER will never exceed sustained level speeds of 1.8 and 2 km/s respectively. That is when they lose all thrust due to velocity.

In practice you won't see much over 1 and 1.3 km/s where thrust starts decreasing. You need to over engineer badly to beat those speeds.

Best test bed would be RAPIER, Mk1 tank, probe core, and shock cone intake. Minimal (if any) wings.

Like i said i do have a jet that can fly at 25k to 30k without falling under 1500m/s with enough fuel to circumnavigate Kerbin atleast 2 times. I was just asking if someone has a better design without exploits like the cargo bay exploit. I know using that exploit you can even reach 2000m/s. Well hopefully someone will come along and share his design.