Super Sonic Speed Help

[AletzN1]

Ok so, I have this jet. The Hawk Moth

I'd say it's pretty big, but it's not huge.

here it is:

It has two landing gear modes.

-Landing/Taxi mode

-Take Off mode

The first pic is on L/T Mode. here is take off mode:

Nothing fancy, it just uses larger landing gear. Allows for a shorter Take Off distance requirement.

But that's besides the point.

What i'm here for, is your help.

T̶h̶e̶ ̶p̶l̶a̶n̶e̶ ̶r̶e̶l̶i̶a̶b̶l̶y̶ ̶r̶e̶a̶c̶h̶e̶s̶ ̶M̶a̶c̶h̶ ̶1̶.̶

B̶u̶t̶ ̶I̶'̶v̶e̶ ̶b̶e̶e̶n̶ ̶t̶r̶y̶i̶n̶g̶ ̶t̶o̶ ̶m̶a̶k̶e̶ ̶i̶t̶ ̶f̶a̶s̶t̶e̶r̶,̶ ̶a̶r̶o̶u̶n̶d̶ ̶M̶a̶c̶h̶ ̶2̶ ̶.̶.̶.̶.̶ ̶m̶a̶y̶b̶e̶ ̶M̶a̶c̶h̶ ̶3̶.̶ ̶B̶u̶t̶ ̶i̶'̶d̶ ̶s̶a̶y̶ ̶t̶h̶a̶t̶'̶s̶ ̶p̶u̶s̶h̶i̶n̶g̶ ̶i̶t̶.̶

Maximum speed is around Mach 3.7

-Structural intakes removed

-Flight optimal fllight altitude has been set at 15000m

Any tips? Methods that you use? Obvious things i'm missing?

If you would like more screenshots, i'd be happy to provide them :3

anddd here's the file. http://www.4shared.com/file/_f4NssCpba/Hawk_MOTH.html

press 2 to toggle the small landing gear.

press 3 to toggle the large landing gear.

Only use the large one when taking off.

Edited July 13, 2015 by AletzN1

[FlipNascar]

Well without a craft file it's hard to see what the exact problem is, and moreover, without any examples of what altitudes you are using when you are unable to attain the speeds, no idea if it's just a case of inappropriate operation or a design fudge...

But from a quick glance you seem to have far too many intakes, they'll add drag and slow you down. You can probably get rid of every single structural intake that surrounds the circular intake.

For best performance you need to get that thing high - the higher the better. Although with the turbojet that you've got you'll find peak performance (in terms of thrust) for the engine is at around 15,000m. Try climbing to 15,000m and then attempting your speed run. For optimum high speed you'd want to use the RAPIER engine because you'll get more performance at a higher altitude ~20,000m.

Hope that helps you on a path to more speed...

[worir4]

Also more boosters!

Seriously try add more engines and also i think 1 ramcone intake or 2 radial intakes per engine should do it. Also get rid of any excess fuel to make it lighter.

[AletzN1]

good advice. Reached Mach 3.7 at 15000m. Originally i reached mach 1 at 1000m. This is a real step up.

here's the file. http://www.4shared.com/file/_f4NssCpba/Hawk_MOTH.html

press 2 to toggle the small landing gear.

press 3 to toggle the large landing gear.

Only use the large one when taking off.

Around half of the fuel tanks are empty.

I would only have one full, but i need something to shift the CoM

[Sharpy]

There's little point adding more jets to get past 1200m/s. Some people reached 1700 but through some extreme trickery and in a plane vastly lighter. Plus at these speeds either you're not getting enough intake air or you're burning up.

What you need now is an "intermediate engine" - something light but with decent thrust and reasonable vacuum ISp (remember, at 10km it's 90% vacuum from the engine ISp standpoint). Aerospike, Reliant, or if you go with bigger planes then Poodle or even Rhino. And of course its fuel. Since you're not using nukes yet, you may need more than one.

Once you reach 1000m/s at about 10km, start climbing some 20-30 degrees up, and when you stop gaining speed, fire the intermediate engines.

At this point KER is priceless as you should nose down just so much that your "Time to Apoapsis" stays the same while you're still gaining speed. (it may crawl up or down, but no more than a tenth of second per second).

At one point, once apoapsis around 50,000 the time will start climbing. Don't worry. Keep rising it.

Once your apoapsis is past 80,000, switch the engines off, then once in the apoapsis, circularize your orbit. Congratulations, you have your first SSTO.

At that point go back to SPH and give it a pair of nukes so that it can go farther than the LKO.