StarDestroyer.Net BBS

Click it.


EDIT: Title.

It works.

Context: I've wanted to do this design ever since I made this other design...

EDIT: thread.

I have a side view being built, but everything forward of the canards other than the leading edge extensions is currently still under construction.

Okay, roughed out. Still need panel lines, canopy frame, etc.

Thanks for the field goal, Keev.

Underside!



And yes, those are isentropic spike inlets that will translate forward at higher Mach numbers. I think this is the High Mach position they're shown at.

Looks good, like a modernised/awsomised F-108. Odd placement on the canards though, which are very small and far back on the chines (doesn't that decrease their effective moment and increase the probability of interfering with the airflow over the wings, which is why the ones on the B-70 are far forward and high?). Does a fighter sized aircraft really have/need 6 engines? It looks like it has spikes in the exhausts as well; are these torodial aerospike nozzles? Could presumably be an escort for your big design, if the latter is used as a bomber.

Starglider wrote:Looks good, like a modernised/awsomised F-108.

Thanks!

Starglider wrote:Odd placement on the canards though, which are very small and far back on the chines (doesn't that decrease their effective moment and increase the probability of interfering with the airflow over the wings, which is why the ones on the B-70 are far forward and high?).

I was thinking they would serve as airflow control devices for high angles of attack, rather like a wing slat.

Starglider wrote:Does a fighter sized aircraft really have/need 6 engines?

It's a bit bigger than a fighter. I can see how you'll think that with the cockpit. I'll be revising that next. It'll be going around Mach 5; 6 dash if we decide to overspeed the inlets and stress the TPS somewhat.

Starglider wrote:It looks like it has spikes in the exhausts as well; are these torodial aerospike nozzles?

Yes, something like that. I'm probably going to extend those outward as well to use as altitude-compensating nozzles.

Starglider wrote:Could presumably be an escort for your big design, if the latter is used as a bomber.

The Bomber? That's an orbital design; this is a hypersonic fast attack plane that flies around 120-140kfeet. It can also be used as a first stage for small satellites, drones or ASATs. This will be armed with RATTLRS missiles or derivatives thereof.

Aerospikes and cockpit done!

Einhander Sn0m4n wrote:I was thinking they would serve as airflow control devices for high angles of attack, rather like a wing slat.

Or perhaps they work like the retractable 'glove vanes' on the F-14A (to counteract centre of lift/centre of gravity shifts). This thing doesn't look like it's going to be dogfighting.

Is this actually done in MS Paint or do you just mean 'could be done in MS Paint if I was a masochist'? I usually use Paint Shop Pro 6 for such things (it took me years to wean off PSP4, now that was a solid piece of software).

Starglider wrote:

Einhander Sn0m4n wrote:I was thinking they would serve as airflow control devices for high angles of attack, rather like a wing slat.

Or perhaps they work like the retractable 'glove vanes' on the F-14A (to counteract centre of lift/centre of gravity shifts).

That's an idea. Maybe they do both!

Starglider wrote:This thing doesn't look like it's going to be dogfighting.

Oh hell no! This is a high-altitude high-speed penetrator, which is a fancy way of saying 'supersonic bomber from Hell'

Starglider wrote:Is this actually done in MS Paint or do you just mean 'could be done in MS Paint if I was a masochist'?

Yup. MSPaint.

Starglider wrote:I usually use Paint Shop Pro 6 for such things (it took me years to wean off PSP4, now that was a solid piece of software).

I tried Photoshop a few times; too complicated

Einhander Sn0m4n wrote:It'll be going around Mach 5; 6 dash if we decide to overspeed the inlets and stress the TPS somewhat.

It had better have a clamshell/capsule ejection system!

Starglider wrote:

Einhander Sn0m4n wrote:It'll be going around Mach 5; 6 dash if we decide to overspeed the inlets and stress the TPS somewhat.

It had better have a clamshell/capsule ejection system!

Bingo

Maybe I'll make it so the whole nose with a bit of the LEXes for stability/aerosurface becomes the eject capsule.

Looks great, Einy! A very interesting design. I don't have the patience to do that effort myself in MS Paint (I've tried to do some Star Wars designs, but it didn't work too well with the mouse).

Mange wrote:Looks great, Einy! A very interesting design. I don't have the patience to do that effort myself in MS Paint (I've tried to do some Star Wars designs, but it didn't work too well with the mouse).

Thanks.


Update:





Added bleed vents and intake doors. BVs are for high-speed operation so as not to overwhelm the engines and cause nasty things like compressor stall, and intake doors are for low-speed (subsonic up to around Mach 1.2) to stop air starvation.

Overall, the system is similar to the SR-71's inlet in terms of bleed vents and bypass doors. However, as it's mostly an external-compression rather than mixed like the SR-71, the spike adjusts in the other direction vs Mach Number than the Blackbird.

Einhander Sn0m4n wrote:Added bleed vents and intake doors. BVs are for high-speed operation so as not to overwhelm the engines and cause nasty things like compressor stall, and intake doors are for low-speed (subsonic up to around Mach 1.2) to stop air starvation.

Good stuff, the A-12 design was very interesting.

However, as it's mostly an external-compression rather than mixed like the SR-71, the spike adjusts in the other direction vs Mach Number than the Blackbird.

My limited understanding of intake design is that conical designs went out of favour and were replaced with square inlets because the later offer more scope for variable geometry (multiple moving ramps, which later developments in aerodynamics allowed the design of) without the extremely high mechanical complexity of something like an irising cone. Though that would look cool, and I would expect 3D designs to have a higher theoretical efficiency.

Starglider wrote:My limited understanding of intake design is that conical designs went out of favour and were replaced with square inlets because the later offer more scope for variable geometry (multiple moving ramps, which later developments in aerodynamics allowed the design of) without the extremely high mechanical complexity of something like an irising cone. Though that would look cool, and I would expect 3D designs to have a higher theoretical efficiency.

My design doesn't iris in or out, it just translates fore and back, like so:



Left is maximum extension for high mach, right is maximum retraction for low mach. Not shown are the open air doors for subsonic flow.

As discussed if it mainly cruises at mach 5 a point design is really fine, as long as there is plenty of excess engine power to accelerate through the suboptimal mach range and the A-12 tricks you mention to make the intakes minimally useful at those speeds. Stuff like irising cones, flexible intake materials and 'aerospike' inlets (high pressure gas injection ahead of the half cone to simulate a larger cone) are just cool sounding but completely impractical concepts to annoy mechanical engineers with.

Starglider wrote:As discussed if it mainly cruises at mach 5 a point design is really fine, as long as there is plenty of excess engine power to accelerate through the suboptimal mach range and the A-12 tricks you mention to make the intakes minimally useful at those speeds. Stuff like irising cones, flexible intake materials and 'aerospike' inlets (high pressure gas injection ahead of the half cone to simulate a larger cone) are just cool sounding but completely impractical concepts to annoy mechanical engineers with.

I'd imagine its 'efficiency band' would be from around Mach 3.5 up to 5.5.

I've also come up with a role for this aircraft: TBO Strategic Suppression of Enemy Air Defense with secondary photorecon and quick attack mission capability. It's a Jumbo-size Wild Weasel armed with nuclear HARMs. It can also likely be used to launch drones off its back like the D-21 Tagboard program attempted to do.

Made sense of the payload section, adding proper electronics and weapons bays. Also added front landing gear doors.

Sticking the payload bay forward of the engine seems like a bad idea unless you can make sure the ejectors can throw the missile/bomb away from the aircraft fast enough to prevent the munition from impacting th engine inlet.

Beowulf wrote:Sticking the payload bay forward of the engine seems like a bad idea unless you can make sure the ejectors can throw the missile/bomb away from the aircraft fast enough to prevent the munition from impacting th engine inlet.

Good thinking. I may just separate the inlets more and stick the weapon bays between them. It'll also solve the problems of just where in the hell I'll put the main landing gear and what to do about fucked up airflow ahead of the engines at Mach.

That won't work. Do it like the B-70, have one single sliding door which slams forward or aft to reveal the bomb bays, allowing hi match ejections